S/i^-e^

THE JOURNAL

OF THE

QUEKETT MICROSCOPICAL CLUB.

VOL. II

1S-70— 187*1.

WOODS
HOLE,
\ MASS.

,>*-,

[Published for the Club,]

BY

ROBERT HARDWICKE, 192, PICCADILLY.

GEO. P. BACON, PRINTER, LEWES.

THE JOUKNAL

OF THE

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^utkttt Uticrostflpttal €luh.

On the Harvest Bug.
{Trombidium Autwnnale.)

By the late J. J. Wright, M.D., Edinburgh.
(Bead Sept. 24th, 1869.;

In many country houses, at this season of the year, among the
many minor miseries of life, not the least is that caused by the
Harvest Bug. They are extremely partial in the distribution of
their attentions. Many people are never bitten by them, others
suffer a martyrdom from their attacks. As far as my own obser-
vations extend, females suffer more than males, which may arise
simply from the greater protection afforded by the dress of the
latter. The Harvest Bug is most abundant in autumn, and it
rarely appears before June or July. They are especially plentiful
on the leaves of the raspberry, the French bean, and in the stubble
fields. They seem to have most partiality for the chalk formations;
for example, they are abundant on the chalk formation of the
Yorkshire Wolds, but very rare on the low lands at the foot of the
hills. Gilbert White in his " Natural History of Selborne," tells
us, " The warreners are much infested by them on the chalky
Downs, where these insects swarm sometimes to so infinite a de-
gree as to discolour their nets, and to give them a reddish cast,
while the men are so bitten as to be thrown into fevers." The
Harvest Bug is also said to attack the lower animals, such as sheep,
dogs, horses, and rabbits.

VOL. II.

B

Z J. J. WRIGHT ON THE HARVEST BUG.

It is probable that the Harvest Bug is the young, or immature
form of some species of tick, which bury their suckers so firmly in
the skins of the animals they infest, that they can rarely be pulled
away without injuring the parasite, or tearing the skin.

The Harvest Bug is of a bright red colour, looking, when upon
the surface of a leaf, or a dark dress, not unlike a very minute grain
of cayenne pepper. Its form is oval, or rather egg-shaped, the an-
terior extremity representing the small end of the egg. The head
is oval, and attached to the abdomen without any intermediate
neck, or constriction. Two lancets project from the anterior part
of the head ; they are curved and lancet shaped ; the point of each
projecting forwards and outwards, and diverging from the one on
the opposite side, so that the convex edges are directed towards
the mesial line. Just below the point of each lancet, aline com-
mences and runs downwards to the centre of its base. At the
under surface of the head, just at the base of the lancets, is a tu-
bular proboscis, mouth, or sucker, which can probably be projected
forwards between the two lancets after they have pierced the skin.
On each side of the base of the lancets is a projecting eye, a dark
looking spot occupying the centre. External to the eyes are the
conical shaped mandibles, attached by a broad base to the under
surface of the head, and terminating in two or three bristles, one
of which appears to be much stouter than the others. The abdomen
is rounded and covered sparingly with long, curved, and rather deli-
cate hairs, which project posteriorly beyond its outline. In the
young state, the state in which it is generally found, the insect has
six legs. After moulting, it is said to acquire an additional pair.
The legs are jointed, covered with longish hairs, and terminate in
three long, curved hooks. The entire insect is extremely soft, deli-
cate, and easily crushed by a very slight pressure.

In all the books I have consulted, it is said that these insects
burrow in the skin of those whom they attack, and that a raised
wheal is caused by their presence in, or beneath the skin. This
quite coincides with the popular opinion ; but I believe it to be en-
tirely erroneous, and for the following reasons. It is difficult to
conceive that a parasite, having such an external form as we have
just described, could penetrate a texture so dense as that of the
human skin. I have repeatedly, and very carefully examined with
a powerful lens, the raised spots, or wheals, without finding the
slightest trace of an opening or track, along which the insect may

J. J. WRIGHT ON THE HARVEST BUG. 3

have been supposed to pass, such as the red line, or burrow of the
itch insect when it leaves its pustule. They may sometimes be
observed adhering to the skin at the top, and centre of the wheals,
after these are fully formed ; at a period therefore, when, if they
burrowed, they might be supposed to be concealed from view.
When examined on the skin, the head, or part of the head is some-
times seen partially covered with an epithelial scale; and this is the
nearest approach to burrowing which I have ever noticed. When ob-
served upon the skin it gives the impression that the lancets are buried
in its substance, while the mandibles and claws firmly grasp the hairs,
or inequalities on the surface of the skin. They are extremely
difficult to remove without completely crushing them, so tena-
ciously do they adhere. No central puncture can be detected in the
wheal, as in the case of the bite of a bug, flea, or gnat : and this
may perhaps be urged as a reason for supposing that the lancets
of the Harvest Bug do not pierce the skin. But its lancets are ex-
tremely small as compared with those of the insects just mentioned,
and they are so arranged as to make an essentially different kind
of opening. Penetrating the skin directly downwards, and then
diverging in the same plane, they will make something like a
simple incision, which from its form, and extreme minuteness, and
from its tendency to close accurately the moment the lancets are
withdrawn, would be far more difficult to detect than the large and
circular puncture of the flea. Further, if the wheal from the sting
of a nettle be examined, which is extremely like that produced by
the bite of the Harvest Bug, it is impossible to detect the point
at which the sting has penetrated, though we are quite sure there
has been a penetration, and the injection of an acrid fluid. Again,
it may be objected, if the incision be so minute and simple in its
form, why should it excite irritation so severe? I suspect, though
this is certainly only a conjecture, that an irritant fluid is poured
into the wound through the minute line, or tube, which passes
through the centre of the lancets. This line appears to me to
bear a strong analogy to the hollow tube which passes through the
fangs of the spider, and which we know to be connected with a
poison sac. That an acrid fluid is injected is also rendered the
more probable from the striking resemblance between the effect pro-
duced by the sting of the nettle, and the bite of the Harvest Bug.
Suppose the insect does burrow beneath, or embed itself in the skin,
what is the object to be accomplished ? It neither deposits its

b 2

4 J. J. WRIGHT ON THE HARVEST BUG.

eggs there, nor does it undergo any further development, as in
the case of the itch insect for example, and some other parasites.
If the Harvest Bug were allowed to remain undisturbed on the
human skin, which, however, is to suppose almost an impossibility,
I imagine it would pierce the skin with its lancets, protrude its
proboscis into the opening, and quietly suck the fluids required for
its nutrition until it underwent a further development, becoming
possibly a true tick.

The above remarks are not intended as anything like a complete
history of the Harvest Bug ; but they are designed to direct atten-
tion chiefly to the structure and supposed burrowing habits of the
insect. There are many points in its history and development
which are altogether unknown, and which I could have wished to
investigate, had not the state of my health precluded the possibility of
further observations. Hitherto, in the books which I have consulted,
I have not seen either a good description, or a correct plate of the
Harvest Bug. The subject may possibly have sufficient interest to
engage the attention of some of the members of this Society.

Malton, Sept. 6, 1869.

Dr. Braithwaite objected to the name " Trombidium " being
applied to this insect, that being the generic name of the common
red earth mite, which he believed to be a totally distinct creature.
He suggested " Leptis " as being more correct, and pointed out that
the six legs of the Harvest Bug do not of necessity indicate it to be
a larval condition, degradation of type being found in all classes.

Mr. M. C. Cooke said that he thought a figure of this creature
would be found in Koch's " Arachniden," and in Kuchenmeister's
"Parasites." He could not agree with Dr. Braithwaite that there
was any evidence of its being a perfect insect. It was agreed by
most zoologists that although we do not know anything of a further
development, that its manifest affinities are with the larval forms of
Acarina, and that it doubtless belongs to the section Trombididas,
which, in the larval form, have six legs. There is a species of
Hydraclina found adhering to the legs of certain Tipulce, and also
those of Dragon-flies whilst in the hexapod state ; but when these
take upon themselves the octopod condition they are purely aquatic.

J. J. WRIGHT ON THE HARVEST BUG. 5

So with this creature, it may afterwards become aquatic, or pass to
some other and different mode of life, in which its prior condition
may not be suspected, and which, of course, has not been traced.
Professor Westwood, some time since, directed the attention of the
members of the Entomological Society to certain immature speci-
mens of Tick which he had found in a dog kennel, but in the hexa-
pod state they possessed such close affinities with the octopod condi-
tion of Ixodes that there was no difficulty in recognizing them.
There is no good ground, therefore, for presuming that there is any
connection between Harvest Mites and Ticks, even in the hexapod
state.

On the Use of the Microscope as an Aid to the
Classification of Animals.

By B. T. Lowne, M.R.C.S. Eng.

(Read October 22nd, 1869.;

There are several ways in which the microscoiDe has afforded im-
portant aid to us in studying the relations of the various classes
and species of animals to each other. Its uses in discriminating the
affinities of the minuter forms of life, and in examining minute
organs, are too obvious to need enlarging upon. Again, the facts
brought to light by means of the microscope, especially during the
past few years, in the embryology and development of animals,
have been of the utmost importance.

It is not, however, to such classes of facts as the above that I
intend to draw your attention to-night, but to a hitherto unworked
field of enquiry.

I believe histological structure, that is, the form and structure
of the ultimate elements of the bodies of animals, is destined to
afford an important clue to their relations to each other, and will
perhaps, when clos,ely studied, go far to settle the great zoological
question of the day — how far animals and plants are related to each
other by descent.

Perhaps it is almost premature for me to speak of this sub-
ject to-night, but its issue is so important, and the facts I have to
bring before you are so suggestive, that I cannot refrain from say-
ing a few words upon it.

On a prima facie view, the histological structures of all animals
appear to be identical ; for instance, the epithelial cells of molluscs,
insects, and vertebrates present the same essential characters. I do
not know of any means by which the conical epithelium of the
stomach of an insect could be distinguished from that of a man,
nor do I know any mode by which gland cells, pigment cells, or
muscular fibres belonging to one class of animals, could be distin-
guished from those of another class.

It is by means of this close resemblance of tissue that
we are mainly enabled to judge of the functions and characters of the

ON THE MICROSCOPE IN THE CLASSIFICATION OF ANIMALS. 7

organs of the invertebrata, especially where they differ materially (as
they usually do), in their structure and appearance from those of ver-
tebrates. In fact, I know of no other sure guide to function except
histological structure.

It is true that the histological tissues of the lower forms of
life frequently exhibit characters which belong to the same
structures in higher animals, whilst yet in an undeveloped or
embryonic condition. For instance, muscles appear to be developed
by the fibrillation of proto-plasm, and in such forms as the higher
Hyclrozoa, the muscles consist merely of proto-plasm, exhibiting
indications of fibrillation. The existence of nuclei in the muscles
of insects has been ascribed to a similar undeveloped condition, but
must, I think, be attributed to rapidity of growth rather than to
any arrest of development, since the muscles of insects exhibit the
utmost perfection of structure, and the nuclei are often absent when
the insect has reached maturity.

Rapidity of growth seems to have an important influence on the
character of all histological tissues, and as far as my observations
go, tends to increase the size of the ultimate elements of the fabric
very materially ; for instance, the muscular fibres and gland cells
of the larva? of insects, are often nearly ten times as large as the
same structures in the perfect state. It has been repeatedly stated
that the muscles of insects have larger fibres than those of verte-
brates, — such is the case in the rapidly growing tissues of the
larva, but I have repeatedly found muscular fibres in insects as
small as ^-qVo of an inch in diameter, which is nearly as small
as any known fibres.

I do not know any more important tissue than muscle, nor any
which presents so complex a problem in its distribution and develop-
ment in different animals.

Two kinds of muscle have usually been described ; these are
known to anatomists as the striated and non-striated varieties.
The structure of striated and non-striated muscle differs very
materially, the former consists of bundles of fibrillar of very minute
diameter, bound together in a membranous sheath so as to form a
muscular fibre, a number of muscular fibres constituting a muscle.
The fibres exhibit regular transverse stria? ; and when the fibres are
broken up by the rupture of the myolemma or sheath, the fibrillar
of which they are composed present the appearance of minute
fibres, presenting alternate dark and light spaces, so that each of

8 B. T. LOWNE ON THE MICROSCOPE IN THE

these fibrillar appears to be made up of a number of alternate cylin-
ders of greater and less opacity. The non-striated muscles consist
of more or less elongated fusiform cells, exhibiting distinct nuclei,
or of long fibres bulging at intervals, and exhibiting nuclei in the
swollen spaces.

In the Vertebrata, these two forms of muscle are constant in their
occurrence ; the former in all the muscles of the body, which serve
the purpose of locomotion as well as all ordinary voluntary, or re-
flex acts ; the latter constitute the muscular coats of the viscera
and blood vessels, except the heart, which has its muscular walls
composed of the striated variety of muscle.

In the Mollusca and Insecta the case is however far different ; in
the former the non-striated, and in the latter the striated varieties
enter into all the muscles, almost without exception ; thus, the walls
of the stomach and intestines of insects exhibit the striated kind,
whilst the elaborate muscular system of the Cephalopoda is en-
tirely composed of non-striated muscle.

In the Annelida again, which forms a large division of the
Annulosa, and which present many characters which show their
close affinity to insects, the non-striated muscle only exists, —
whilst the Ascidians, a group of the Molluscoida, according to the
best authorities, possess striated muscular fibres.

This irregular distribution of striated and non-striated muscle is
worthy of careful consideration, but especially in relation to the
origin of species ; much has yet to be done in working out the re-
lation of the one kind of fibre to the other. To say the least, it is
a fact yet to be accounted for by those who believe in the descent of
several types from a common ancestor.

Other facts of a kindred nature might be carefully worked out,
and the results of such investigation may have the most important
issue.

The close resemblance of the Spermatozoa of the most widely
separated groups of animals, and their great diversity of form and
size in nearly allied types, are facts, the import of which are at
present not understood. The apparent identity of nerve cells and
fibres in the most diverse types, together with the strange manner
in which the different kinds of muscular fibres are distributed, the
absolute unity of structure existing side by side with the greatest
diversity of type and form, are all facts bearing upon the same
great problem. I commend them to your notice, gentlemen, feeling

CLASSIFICATION OF ANIMALS. 9

sure that they present fruitful fields of enquiry to every naturalist,
and I hope many years will not elapse before I shall be in a position
to lay something much more tangible upon this important subject
before you.

I would suggest, in conclusion, the immense advantage of nume-
rous workers in this branch of research, and that each of you who
are conversant with the different varieties of tissue, should take every
opportunity of making such observations as opportunities occur,
whilst reports of all such researches, even if they extended only to
some single species, and even to a single tissue, would form most
valuable notes, and be a great addition to the Journal. Elaborate
papers are not necessary, so that each member will bring the note
of a single careful observation.

10

On Some Portions of Skin, supposed to be Human, found on a
Door in Westminster Abbey. By Henry F. Hailes.

(Read October 22nd, 1869.J

I have placed under a microscope upon one of the tables an object
"which may be considered rather as an archaeological than a micro-
scopical curiosity. It is a portion of skin taken from one of the
doors of Westminster Abbey. Some explanation is necessary in
order to make this object intelligible ; I have therefore gathered
together a few particulars, chiefly from Dean Stanley's " Memorials
of Westminster Abbey."

In the eastern cloisters of Westminster Abbey is a door which
is never opened except in the presence of the Secretary of the
Treasury, the Chancellor of the Exchequer, and the Comptroller of
the Exchequer. This door leads into a chamber in the old Norman
substructures, beneath the original dormitory of the monastery.

This chamber is the Treasury of England, of which the Prime
Minister is the First Lord and the Chancellor of the Exchequer
the administrator. It it now better known as the " Chapel of the
Pyx."

In this chamber were kept, up to the year 1303, the choicest
treasures of the State ; the Regalia, sundry relics, and a large
hoard of money*

In the year 1303, the King (Edward I.) being at Linlithgow,
this treasure was carried off by thieves. The chief robber appears
to have been one Richard de Podlicote, who, having previously
broken into the Chapter-house and robbed the Refectory of a large
quantity of plate, had thus ascertained the precise position of the
Treasury, and afterwards concerted with his friends (some of whom
were within the precincts of the Abbey), and with their aid carried
out the robbery.

The treasure, after it was taken out, was concealed in some
hemp (planted it is believed for that purpose) growing in the clois-
ters, and was afterwards conveyed in two black panniers across the
river to the " King's bridge," by the monk Alexander of Pershore
and others.

The abbot and the eighty monks residing in the Abbey, were
taken to the Tower and tried, but were all released with the excep-
tion of the sub-prior and the sacrist.

H. F. HAILES ON SOME SUPPOSED HUMAN SKIN. 11

The approach to the Treasury from the north side was walled
off, and the Treasury thus reduced in size. Inside and outside of
the door by which this passage is entered is nailed the skin of a
man. The door of the Sacristy, in the south transept of the Abbey, has
also been decorated in a similar manner.

The more valuable part of the treasures was thenceforward kept
elsewhere, and the " Pyx Chapel " was used only to keep the
Regalia, relics, some records, and the " Pyx," or box containing
the dies of the coin of the realm. The Regalia have since been
removed to the Tower, the relics were probably destroyed at the
Reformation, and the chamber is now used, I believe, only for the
" Pyx," and for the standard weights and measures. It is guarded
with great care, and only opened once in five years, as before said,
by the Prime Minister, Chancellor of the Exchequer, and the
Comptroller of the Exchequer, for the time being, with much
ceremony.

The fragments of skin exhibited are from the door leading to
the " Pyx Chapel." They clearly show the roots of hairs ; cer-
tainly more resembling those of the human body than they do any
other animal that I know of, but they do not appear to me to be
those of a " fair-haired man," as asserted by Dean Stanley. This,
however, would rather tend to bear out his theory, that these skins
are not those of sacrilegious Danes as is generally supposed, but
are more probably the skins of those concerned in the robbery.
We are not informed what was the fate of Richard de Podlicote and
his accomplices, but it seems probable that they were executed, and
that the sacrist's skin was displayed upon his own door, whilst the
other two may have served to line the inside and outside of the
door leading to the Pyx chamber.

12

A Simple Form of Selenite Stage. By W. Hislop, F.R.A.S.

(Bead Nov. 26th, 1869.)

A short time since I endeavoured to point out the necessity of a
closer attention to the mechanical arrangement of the polariscope
as applied to the microscope, in order to render the advantages of
illumination by polarized light, more generally available. As a
contribution to this end, I described a piece of apparatus which
I had contrived, used, and exhibited for some time, and which I
called an Analyzing Selenite Stage ; the arrangements of which
were so contrived as to contain three separate films of selenite, and
to give them the power of rotation in all directions, together or
separately, and in close contact with the object under examination.
The facility with which this could be done, and the proper effect
produced and registered for each object was also pointed out.

Since then the use of that instrument has produced some curious
results, and the simple arrangement which I have now to describe
is one of them, and will, I think, greatly increase the range of the
ordinary forms of polarizing apparatus, without the necessity of
incurring the expense of more elaborate contrivances.

I merely avail myself of a previously known fact — namely, that if
a film of mica be superimposed on a film of selenite, the colour
transmitted by the latter will be much modified. I find that if we
take a film of selenite producing, say, a blue colour, and if we
superimpose on that a film of mica, of say '002 in thickness, and
separate their axes of polarization by a certain angle, we obtain by the
combination nearly all the colours which we have got by different
films of selenite. I cannot fix the exact angle of divergence, as it
varies with different specimens of mica, but it is easily ascertained
by trial.

To make this compound film available, I use first an ordinary brass
slide about 3 inches by 1 1 of an-inch (See Fig.), with a ledge at the

(JO

W. HISLOP ON A SIMPLE FORM OF SELENITE STAGE. 13

lower side. The central portion of the slide is turned out with a flange,
so that a brass ring may be made to revolve in it easily. The film of
selenite, and the film of mica are cemented into this ring in the pro-
per relative position to give the desired effect, and eight notches
are cut in the edge of the disc. When the mounted object is
placed on this brass slide, the edge of the disc projects beyond the
slip, and it is easy to turn it through a portion of a revolution
without disturbing the object, by using a hooked wire or even the
point of a penknife.

If now the colour given during the rotation of the analyzer be
blue and yellow, by simply turning the disc holding the compound
film through one-eighth of a revolution these colours will give place
to their complementary ones, namely, — red and green ; and they
will be given as brilliantly as they can be obtained by more compli-
cated arrangements. Intermediate positions give other tints.

Further, this contrivance enables us to employ that most effective
element, namely, the rotation of the depolarizing film to suit the
various planes of double refraction in the object under examination,
and it does this in an easy and inexpensive manner.

14

On the Different Methods of Measuring
Microscopical Objects.

Memoir by Count A. F. Castracane cV Antelminelli.
(Read November 26th, 1869. J

It is not only to those who contemplate the immensity of the celes-
tial bodies, or the wonderful harmony of the stars, and of their
movements, that it is given to feel themselves transported with
amazement when reflecting on the infinite wisdom of the Creator.
The earth and the sea, under whatever aspect they are regarded,
and even in most minute details, give evident proof that all proceeds
from the same infinite, ordaining Mind. Or rather, all that pro-
ceeds from the hands of the highest Artificer cannot but be equally
stupendous in itself, so that man feels himself compelled to marvel
more when he reflects on the organization of the most humble
flower of the field, or on the structure of the smallest fly, than he
does at the sight of an aged oak, or at the immense bulk of an
elephant. Hence, we can safely say that there is no more ineffable
or purer pleasure than that which is afforded to him who, with the
aid of the microscope, investigates the marvels of minute structure
so eminently calculated to exalt the mind to the admiration of Infi-
nite Creative Wisdom.

However, the micrographical observer does not have the gratui-
tous enjoyment of his satisfaction, since he has very often to en-
counter difficulties which must be overcome, aud has inevitable an-
noyances to bear. Among other things, the nricroscopist, and es-
pecially one who attends to the study of the Diatomacea?, finds
himself constantly obliged to take and to register the measures of
the objects which he has before his eyes, and to calculate the mi-
nuteness of details, which are often so small that more than a
thousand could be contained in the space of a millimetre.

For taking these measures and computing the wonderful small-
ness of these particles, numerous are the means at the disposal of
the student, who, with different methods and by different ways, can
attain his desired object with more or less facility and exactitude ;
and of these I intend to treat. On such a subject I do not pre-
tend to say anything new ; I shall only rewrite, in a few words, as

ON MEASURING MICROSCOPICAL OB ECTS. 15

much as I have been able to collect from the best treatises which
have been written on the subject : I shall, however, speak from
experiments made by myself, to which I have united a few practical
particulars which from time to time I have ascertained to be the
most useful. I hope however, it will not be altogether useless to
make known the means I make use of, thus, as it were, clearing the
way for those who wish to undertake similar researches, or who
wish to become expert in the use of the microscope.

From the first moment when I undertook the study of the Dia-
tomaceae, I was induced to occupy myself with their measurement
as one of the data which might serve for the determination of the
species, and for the identification of the subjects which I had under
my eyes, with the species described in Smith's Synopsis of the
British Diatomacese, and in the works of Kiitzing, Rabenhorst and
others. The easiest system for taking such measurements is that
founded on the use of the Camera Lucida, an invention which is due
to the celebrated English savant, Wollaston, in 1807, which has
been successively modified and perfected by the illustrious German
anatomist, Soemering, the French opticians, Chevallier and Nachet,
and the Italian Professor, John Baptist Amici, whose name is con-
nected with nearly all the improvements in the microscope.

The Camera Lucida consists essentially of a reflecting surface,
which forms an angle of forty -five degrees with the axis of the
microscope, which surface must be such as to permit the simul-
taneous view of the object disposed in the field of the instrument,
and of the plane on which the same image is reflected. It is then
extremely easy for anyone whose hand is trained to the use of the
pencil, to draw, by these means, the object under observation, fol-
lowing all the contours, and making, as it were, a tracing. Some-
times, however, he finds some difficulty in seeing with ease, at the
same time, the reflected image, the contour already drawn, and the
point of the pencil which is completing the drawing. This incon-
venience arises from the want of a just relation between the illumi-
nation of the field of the microscope and that of the plane on
which he is drawing. Thus, if the former is very much illuminated
and the paper in shade, it will be difficult to have a simultaneous
view of the object and of the drawing he is making. Such an in-
convenience must be carefully obviated by diminishing the concen-
tration of the light in the field, or by selecting a position in which
the plane on which the drawing is being made will be better
illuminated.

16 ON THE DIFFERENT METHODS OF MEASURING

Having completed by this method the drawing of the object, or
simply indicated the extremities, the application of a metrical
measure "will immediately give the dimensions, increased precisely
in proportion to the magnifying power used in the microscope ;
from which it results that the real size of the object is equal to the
apparent size divided by the magnifying power, in diameters. It is,
however, essential to remember, that in order to obtain with the
Camera Lucida, a drawing corresponding in dimensions to the in-
crease obtained in the field of vision, the distance from the reflecting
point to the plane in which the drawing is being made must be
precisely equal to the distance from the same point of the object
under observation ; while the drawing and the measure which is
deduced from it will be greater or smaller than the dimensions
presented by the object in the field of the instrument in proportion
as the height of the Camera Lucida from the plane of the drawing
may be greater or less than is correct.

Such is the most prompt and most practical method of determin-
ing the dimensions of objects which are observed under the mi-
croscope. Still, such a determination is a thing of very little im-
portance, if not even a mere matter of curiosity. The same cannot
be said, on the other hand, of the number of stride, or rows of dots,
or of cells, which may occupy a given space on the surface of the
observed object. Although up to the present time those who are
engaged in observing the Diatomaceze are not agreed in recognising
the importance of such a datum in regard to the value it may have
as a diagnostic character, yet it is generally acknowledged that, at
any rate, within certain limits of variableness, the number of the
stride which cover the valve of a Diatomaceae, is one of the means
of identification of the species to which it belongs. It is, however,
useless to trust to the means of the Camera Lucida for determining
the thickness of the striee, so close together and so fine are they ;
for this purpose it is necessary to have recourse to means of much
more exquisite delicacy.

A process answering better for this purpose is found in the use
of the eyepiece micrometer, which is nothing but a measure adjusted
to the eyepiece, from which measure is determined the value, in re-
lation to the magnifying power used by means of a millimetre cut
on glass, and divided into hundredths and placed under the objec-
tive. The commonest form is that of a thin plate of glass, on
which is engraved a series of equal divisions, and in order to
facilitate the reading every fifth and tenth mark is longer than the

MICROSCOPICAL OBJECTS. 17

others. Such divisions fixed in the focus of the eyepiece are seen
ajross the field of the microscope, in such a manner as to see
contemporaneously and with the greatest fineness and distinctness
the object which it is wished to measure, and the divisions. Let
us suppose that the object has transverse lines, of which we
wish to know the intervals, in order to deduce what number
would be required to occupy the space of a millimetre. To ob-
tain this I arrange the object under the eyepiece micrometer,
in such a manner that the striae may be parallel to the divi-
sions of the micrometer, and by causing one of the divisions
to be superimposed, and to coincide with one of the striae, I
determine how many of them there are in the space of one or
more of the divisions, taking notice that the observation will be
the nearer to the truth in proportion as it extends over a greater
number of divisions. Knowing the value of the ocular divisions
in relation to the magnifying power used, with a very simple equa-
tion we obtain the number of the striae in the object corresponding
to one millimetre.

Thus, for example, I take for observation a Diatom in the
shape of a boat, in which the central nodule is seen to be dilated
transversely, and I recognize it as a Stauroneis Phoenicenteron
(Ehrbg). The valves of this Diatom are ornamented with very fine
moniliform striae, and rows of granules. I wish to know their
thickness or the number of them which correspond to a millimetre.
For that purpose : 1st, — I adapt to the microscope a micrometer
eyepiece : 2nd, — I cause the division to be superimposed
on the lines of the Stauroneis, exactly combining one of them
with one of the divisions : 3rd, — I count the striae comprised be-
tween five divisions of the micrometer, and find they are exactly
eight. I ought now to ascertain the value of a unit in the division
of the eyepiece, and I obtain it by substituting for the preparation
placed under the microscope an objective micrometer, that is to say,
a millimetre divided into a hundred parts, and cut on a thin glass ;
and recognizing that in the magnifying power used forty-nine
divisions of the eyepiece correspond to six hundredths of a milli-
metre ; I establish the proportion : 49 : 0. 66 m m : : 1 : x. Thence
a^% m = 0.001224 m m , which is the value of a unit in our case.
Now, since eight was the number of the striae which were counted
in five units of the ocular micrometer, we ought to say : if in
5 x 0.001224 mm there are eight striae, how many are there in one

VOL. II. c

18 ON THE DIFFERENT METHODS OF MEASURING

millimetre ? And the final result will be .oo6i 8 2mm= 13 °7- Whence
the stride of the Stauroneis Phcenicenteron are of such fineness
that 1307 of them are contained in a millimetre.

Although such a method of taking small measures may be cor-
rect in theory, and in most cases is found the most practical, yet in
many circumstances of recognizing the finest details it becomes a
difficult and uncertain method. And this is specially the case when
one has to do with the most difficult Diatomacea3, the study of
which requires the most powerful objectives, and the most accurate
direction of the illumination. Anyone who has familiarised him-
self with the study of these can well bear me witness how the per-
ception of very fine strige requires a sustained tension of the visual
faculty, so that one frequently hesitates, and it is not always possi-
ble to recognize without hesitation and with certainty the number
of very minute stride which may be confined in an interval which,
relatively to the magnifying power used, and to the infinite small-
ness of the details, appears considerable. Such an inconvenience I
have been able partly to obviate by the use of variable eyepiece
micrometers. I have two of these, one with cobweb lines, con-
structed by Nachet, of Paris, the other with variable points by
Hartnack ; the two lines or threads of the first and the two points
of the second are separated from each other to a given distance,
which is determined in the first place by comparison with an objec-
tive micrometer. The Diatom being placed in the middle of the
field of vision under the variable micrometer, the number of striae
is determined, either at one glance or by very slowly advancing
one of the lines or one of the points, and fixing all the attention
on the point or line in motion, and on the crossing made succes-
sively by the stria3, from which it is possible to determine the
number.

But still, this method presents a grave difficulty in the oscilla-
tion which is inevitably communicated to the instruments, so that
more striae seem to pass before or behind the moveable point, so
that here again I find myself in uncertainty and in the fear of
erring. Such difficulties cannot be overcome otherwise than by
rendering the eyepiece micrometer independent of the body of the
microscope, by fitting to it a supporting foot distinct from the
mounting in question. In the absence of such an arrangement,
when I am about to occupy myself with the Diatomaceae, which
are most difficult, on account of the extreme delicacy of the stria-

MICROSCOPICAL OBJECTS. 19

tion with which they are adorned, I usually approach the two
points of Hartnack's micrometer very close, so as to be able to
include in the interval only one or two stria3 which I judge I can
easily keep within view. Afterwards I substitute for the micro-
scopic preparation, in the plane of the object-holder, the objective
micrometer, with the micrometer cut on the glass, with the Camera
Lucida ; I draw the interval between the two points, and that of a
hundredth of a millimetre magnified in the microscope, and by ob-
serving the number of times that the latter is greater than the for-
mer, and multiplying it by the number of strife observed between
the two points, I obtain the number of strife contained in one hun-
dredth of a millimetre, and consequently the number contained in
a millimetre.

All these systems certainly give an approximative idea of the
measures, but we cannot expect from them an exact and precise
determination, and this so much the more in proportion as the
basis of the calculation maybe smaller; — seeing that any error
there may be in the first place, though only of a fraction of a stria
by being multiplied as many times as the smallest space is com-
prised in the measure of the millimetre magnified in the micros-
cope, may amount to a sufficiently notable difference from the
truth. And this I think may be the origin of the differences in the
number of the striae which are observed in the Diatomaceae of the
most distinguished micrographers, who purposely and specially, or
only accidentally, have occupied themselves with the Diatomacete,
in order to the determination of the species to which they
belong. Having, however, proposed to occupy myself principally
with the study of this interesting class of organisms, I was led to
think of some method which, by facilitating the operation, would
lead me to a more exact estimation, rendering it not only possible,
but relatively easy, to count the striae, and in consequence deter-
mine their sizes and that of their intervals.

Such a method I find in the habitual use of Photo-Micrography,
by which means I reproduce the different forms which present
themselves in my researches. Having proposed to myself to edit a
most complete photographic monograph of the whole order of the
Diatomaceae, in which I have up to the present time included
nearly a thousand types, I adopted the magnifying power of 535
diameters for the reproduction of these, so that I could keep an
approximative account of the relation of size between one type and

c 2

20 ON MEASURING MICROSCOPICAL OBJECTS.

another. The images which I obtain directly, and which are usually
called by photographers, negatives, from which I print off so
many identical proofs, are obtained on plates of glass. These
present with the greatest fineness and fidelity, not only the form of
the Diatomaceae, but even the finest details, which can only be
perceived with doubt and great trouble when observing them di-
rectly under the microscope. Would that we could obtain equally
fine results in the positive which is printed on paper, and which,
by the imperfection of the surface presenting small asperities of ele-
vated and depressed points, does not perfectly and equally ad-
here to the glass of the negative, and is far from presenting the
same degree of fineness ! Having thus at my disposition the most
faithful and authentic representation of the Diatomaceae on a plate
of glass, I direct my attention to this, and on it I follow the enu-
meration of the striae. To facilitate the enumeration I count the
lines which correspond to a hundredth of a milimetre, multiplied
five hundred and thirty-five times, and I see how many lines are
included in a space of the negative equal to 5. 35 m m . This
measure, cut on a thin metallic plate and placed on the negative or
matrix, gives the greatest facility for obtaining the number which,
multiplied by a hundred, will give as the final result, the precise
number of stria?, or rows of dots, which cover the valves of the
Diatomacese.

Those, however, who are not able to have recourse to Photo-
Micrography, which also offers the incalculable advantage of giving
as it were, an authentic reproduction of the objects under study,
in order to be as near as possible to the truth, ought to have re-
course to repeated measurements according to different methods,
assuming for the final result, the mean number obtained by the
repeated operations.

Translated from the Italian, Nov. 16th, 1869.

21

NEW BOOK

The Anatomy and Physiology of the Blow-Fly (Musca Vomitorid). — ■
A Monograph. By Benjamin Thompson Lowne, M.R.C.S.
Eng. Illustrated with ten plates. London : Van Voorst ;
pp. 121. 8vo.

We have been favoured with a sight of the proof sheets of the
above work, which is now nearly ready for issue to the subscribers.
We have not time to execute a review which shall do justice to the
merits of Mr. Lowne's elaborate monograph, and, in fact, we doubt
whether much more could be done than refer to the work itself.
A more comprehensive treatise on the microscopic anatomy of a
single insect has, probably, never been published, and we sincerely
hope that the author's labours will receive their due appreciation.
We feel bound to add that this work owes its origin to the Quekett
Microsco]:>ical Club,

On the Observations necessary for Correcting Object
Glasses. By F. H. Wenham.*

For this purpose, a particle of mercury is placed upon a slip of
black glass. A piece of watch spring, or the thin handle of a spatula,
is held up at its end by the fore-finger of the left hand, and slapped
smartly down on the mercury, which is thus beaten into powder in
the form of numerous minute globules. Of these, a larger size is
selected for correction for colour, and a minute one for ascertaining
the errors of figure and centering and state of the oblique pencils.

The globule must be illuminated by direct candle or lamp-light,
and not by daylight, as the latter will not allow perfect correction
to be obtained. The light requires to be set as close as it can be,
and, of course, in the highest powers when there is little distance
in front it must be very oblique, but this is of no consequence, as
it is not the globule itself, but the spot of light reflected from it that
is required to be seen.

The lens to be tested is adapted to the microscope having the
ordinary Huyghenian eyepiece. On placing the globule either in or

* Extracted from trie Monthly Microscopical Journal.

22 F. H. WEXHAM OX THE OBSERVATIONS NECESSARY

out of focus the luminous point expands into a ring. If the object
glass is under-corrected for colour as in a single lens, the bright
ring appears within the focus, the outer margin is red, and the inner
circle green. If the lens is over-corrected the bright ring appears
without the focus, with the colours in the same order as before. A
practical knowledge only derived from these appearances can deter-
mine the amount of concavity to be given to the flint, or difference
of convexity in the crown, for obtaining the desired correction; but
even in the most experienced hands it generally involves several
alterations to secure perfect achromatism. When this is corrected
as far as practicable, a pale green colour only is perceptible beyond
the focus. This arises from the secondary spectrum or relative
difference in the width of the prismatic colour spaces of the crown
and flint, and seems to be a variable condition, according to the
composition of the glass employed.

Though correction for spherical aberration is intimately related
to that of colour, a single lens, when finally achromatised, being
also nearly free from spherical error, yet in a combination of three
pair, when matched so as to be achromatic, this may be so con-
siderable as to render the object glass useless, and is oftentimes
exceedingly troublesome to remedy. The error may arise from an
improper proportion between the relative foci of the lenses — as the
back being too long. I have before stated that in the form that I
have advocated the spherical aberration is mainly corrected by
giving thickness' to the front lens, and by properly adjusting the
distance between them. In a glass spherically under-corrected the
light from the globule is greatest within the focus, and when set
out of focus, speedily vanishes and becomes diffused ; in the case
of spherical over-correction the contrary appearances result. When
the relative distance of the lenses is rightly adjusted, the light
spot expands equally, and is of the same intensity for a short dis-
tance on either side of the focus, in which the globule should ap-
pear with a clear bright margin. The object-glass is now in a
proper condition for testing the errors of construction and work-
manship.

To examine the condition of the oblique pencils, and consequent
flatness and distinctness throughout the field, a small globule is
selected and brought to the edge, using the lowest eyepiece. If
the bright point in the centre of the globule, when a little out of
focus, approaches to the inner side of the concentric light rings, it

FOR CORRECTING OBJECT CLASSES. 23

is termed " outward coma," and indicates that the front incident
surface of the back triple is too convex. If, on the other hand,
the bright spot is on the outer side of the rings, or next the margin
of the field of view, there is " inward coma," which shows that this
same surface is too flat. I have previously remarked that this
curve has a powerful effect on the flatness of field, and perfection
of the oblique pencils, and for them no other correction is generally
requisite than an alteration in this radius.

Before the glasses are finally cemented in their cells, they should
be carefully tested for centering ; for this purpose a very minute
globule is selected and placed exactly in the centre of the field. If
the bright spot appears excentric, the pair of lenses which occasion
the error should be shifted on each other while warm enough to
cause the Canada balsam by which they are cemented together to
yield, till on repeated trial the error is corrected. This is impor-
tant, as the least fault in centering materially impairs the per-
formance of an object-glass.

There is yet one other globule test for object-glasses to indicate
accuracy of workmanship, or whether the lenses are worked to
true spherical surfaces. If the rings from a minute globule appear
of an irregular wavy outline, either approximately to a polygon or
a triangle, it shows that one of the surfaces at least that refracts
the rays is of this form. Such workmanship is inexcusable, and
those that cannot avoid it had better let glass grinding alone.

Finally, there is an appearance that I have sometimes seen in
our best object-glasses, when focussed away from a globule, viz.,
" Newton's rings." This shows that in the contact surfaces of one
of the pair of lenses the convex is deeper than the concave, and
bears hard in the middle. This may have no worse effect than the
loss of light, but still it is as well avoided.

24

QUEKETT MICKOSCOPICAL CLUB.

OKDINAKY MEETING.

SEPTEMBER 24th, 1869.

P. Le Neve Foster, Esq., President, in the Chair.

The minutes of the preceding meeting were read and approved.

The following donations were announced : —

"Science Gossip" and "The Monthly Microscopical Journal," from the
Publisher ; " Land and Water," from the Editor. Curtis's Photographs of the
19th band of Robert's Test-plates, consisting of three positives and two glass
negatives, from the Surgeon-General U.S.A. Army, Washington; four Coloured
Drawings of the Transitional Stages of the Privet Hawk Moth, by Cyril B.
Harcourt ; three Microscopic Preparations of Trombidium Autumnale, illustra-
tive of Dr. Wright's paper, from the late Dr. Wright and Miss Webb ; " Maxime
miranda in minimis," from Mr. Pichter ; Pamphlet on Reade's Prism, from Mr.
Highley ; one slide of the Harvest Bug, from Mr. Curties.

The thanks of the Club were returned to the donors.

The Secretary read a paper, by the late Dr. J. J, Wright, "on the Harvest
Bug."

A short discussion ensued.

Mr. Wright described a method whereby Reade's prism might be used as a
polariscope by attaching a bundle of thin glass plates to one face of it.

The Secretary described a new form of microscope for aquarium observation,
invented by Mr. J. W. Stevenson.

Votes of thanks were accorded for the various papers read.

The President announced that the subscription list to the Bywater testimonial
would be closed On the 30th instant.

The names of five gentlemen proposed at the last meeting were ballotted for,
and declared duly elected.

The Secretary announced that the following objects among others were about
to be exhibited : — Fredericella sultana, by Mr. Golding ; Ballia callitriclia, by
Mr. Wright; Pleurosigma balticum. with Reade's prism, by Mr. Suffolk ; three
beautifully coloured drawings of the House Fly and Spider, by Mr. Richter.

The Secretary announced that Mr. Suffolk's course of lectures was being pub-
lished in the " Chemical News."

Dr. Braithwaite announced that he was about to deliver a course of lectures
on Bryology, to members of the Club, at his house, on the second and fourth
Thursdays in each month, commencing in October. Those who wished to attend
were requested to send in their names at once.

Mr. Suffolk expressed his willingness to repeat his course of lectures at the
commencement of the ensuing year, should a sufficient number of members
present themselves to form a class.

25

The names of the following gentlemen were proposed for membership : — Mr.
C. J. Fox, Mr. Cyril B. Harcourt, Mr. Henry Davis, Mr. J. D. Rendell, and
Mr. W. F. Shore.

A paper by Mr. Lowne was announced for the next meeting, as also the ex-
cursion for the ensuing month, and the proceedings terminated in the usual
manner.

ORDINARY MEETING.

OCTOBER 22nd, 1869.

P. Le Neve Foster, Esq., President, in the Chair,

The minutes of the preceding meeting were read and approved.

The following donations were announced: — "Science Gossip" and "The
Monthly Microscopical Journal," from the Publisher; "Land and Water,"
from the Editor; Huxley's "Introduction to the Classification of Animals,"
from Mr. Arnold; fifty slides from Mr. M. C. Cooke; two slides from Mr.
Curties ; one slide from Mr, Tat em.

The thanks of the members were returned to the respective donors.

Five gentlemen proposed at the previous meeting were then ballotted for, and
declared duly elected.

Mr. B. T. Lowne read a paper " On the Aid Derivable from the Microscope
in the Classification of Animals."

Dr. Braithwaite made a few remarks on the remarkable character of Mr.
Lowne's paper, and expressed his conviction that the investigation of the subject
could not be in better hands.

Mr. Hailes read a paper " On some Portions of Skin supposed to be Human,
found on a door in Westminster Abbey."

Thanks were voted for the papers read.

A number of objects were announced for exhibition.

The following gentlemen were proposed for membership : — Messrs. E. M.
Chater, Ed. Hart, Edmund Perken, and George Naylor Stoker, F.E.M.S.

The Secretary called attention to the extra meetings, and expressed his con-
viction they formed a characteristic distinction of the Club.

The proceedings terminated in the usual manner.

ORDINARY MEETING.

NOVEMBER 26th, 1869.
P. Le Neve Foster, Esq., President, in the Chair.

The minutes of the preceding meeting were read and approved.

The following donations to the Club were announced :— "The Chemical
.News," from the Publisher and Mr. Suffolk; " Science Gossip" and " The
Monthly Microscopical Journal," from the Publisher ; " Nature, " from the
Publisher ; " Taylor's Scientific Calendar for 1870," from the Publishers ;
twelve slides from Mr. Curties ; six slides from the Secretary ; ' ' Land and
Water," from the Editor ; specimens of Sponge Sand, from Mr. Lemon.

26

Thanks were voted to the donors.

Mr. Durham described a microscope designed by Mr. Marshall, President of
the Birmingham Natural History Society, and made by Mr. Field. It was
contained in a case which comprised a simple microscope with five or six powers,
with a cell for dissecting and pins for setting out an object. The dissecting
stage being removed, a mounting plate was put in its place with a contrivance
for centering and a turntable. The case also contained a tray, with mounting
materials and slides, and a drawer with dissecting implements. A tube or
body could be attached , so as to convert the instrument into a compound
microscope with a good achromatic combination, and also other apparatus ;
the price of the whole being £3 10s .

Mr. Durham also read a letter from Mr. Tomlinson, calling the attention of
members to the motions of particles of Camphor. It was said that small
fragments of camphor would rotate if placed on any smooth, clean, solid
surface, and that the motion might be seen under the microscope; members
were invited to repeat the experiment, and communicate the results to Prof.
Tomlinson for publication.

The President announced that the four gentlemen proposed at the last meet-
ing had been ballotted for, and elected members of the Club.

Mr. Hislop read a description of a new simple Selenite Stage.

Mr. M. C. Cooke read the translation of a paper by Count A. F. Castracane,
" On Micrometric Measurement."

Dr. Matthews pointed out that in measuring by the aid of the Camera Lucida,
the amount of light diminishes as the object is enlarged, and that a different
calculation is required for each eyepiece and objective used. As to diatom
markings, they were variable even in different parts of the same valve ; with
cobwebs also it was difficult to say where to begin the measurement.

Mr. Lowne had made all his measurements with the Camera Lucida, makinga
scale from the stage micrometer, and always using the same objectives and
eyepieces, and the same distances from the paper. There were, however, one
or two little points which required some attention, and which every novice
finds a matter of extreme difficulty, because he does not get a due balance of
light between the object and the paper. By using a reflected light from the
plane mirror for the object, and a direct light from a lamp for the paper, ad-
justed according to the requirements of the object, there would be no trouble
in the matter. For all rough measurements it was far the best method, though
for diatoms it might be necessary to use something more delicate, but no
difficulty would be experienced in camera lucida measurements down to 100
diameters.

Mr. Breese had found that the ordinary Beale's neutral tint reflector, with a
micrometer on the stage, would give measurements as approximate as were re-
quired for all ordinary purposes. The method proposed by Dr. Matthews
would give as good results as anything, with fine measurements, provided that
one of the points were moved by a tangent screw.

Dr. Matthews said that he had mentioned in his paper that the handles of
his micrometer might be worked by tangent screws j these had since been added,
and leave nothing to be desired. In using high powers it is a matter of great
importance to have perfect steadiness, and when a tangent screw is used the
motion is as delicate as could be wished ; it was not necessary to have a tangent
screw to both points. He should be happy to show the instrument again with
this improvement added.

27

The Secretary read an extract from " The Photographic News," describing
the Albertype process, and suggested its applicability to the illustration of
books on Microscopy. Specimens of the process were exhibited. The cost of
prints, Gin. by 8in. was stated to be sixpence each, which sum was subsequently
doubted as being too large.

Mr. Breese pointed out that the specimens exhibited were soft and well
adapted to likenesses, but they were without detail, and therefore quite useless
for microscopic purposes.

Among other objects exhibited attention was called to Amphipleura pellu-
cida (acus), shewn by Mr, Powell, with one-eighth Immersion lens.

The following gentlemen were proposed for membership : — Messrs. Henry
Jones Coppock, John Salmon, Gilbert Sanders, Benjamin D. Jackson, F.L.S.,
William Parker, M.D., George Ackland Ames, D. W, Hill, Thomas Lloyd,
and Arthur Brewin, F.R.A.S., F.R.M.S.

PRESENTATION OF A TESTIMONIAL TO MR. BY WATER.

The President having vacated the chair, it was taken by

Mr. Arthur E. Durham, who said that on no previous occasion had he occu-
pied that chair with so much pleasure, and he considered that great courtesy had
been shewn him in requesting him to do so now. All present knew how the
Club had originated, and what a marked and signal success had attended it since
its commencement. Amongst those of its first founders, and those who had
done most to contribute to its success, no one had been more active than Mr.
By water, who for the past four years had been its Honorary Secretary ; he
knew that in discharging the onerous duties of his office no secretary ever did
his work in a more indefatigable manner, or with such hearty good will. At
length a time came when he found his labours crowned with success, and the
Club in such a vigorous condition as to be able to go on without such constant
care, and feeling that he might safely lay down his charge, he had resolved to
retire from the office he held so long. We felt that we ought to render him
some acknowledgment of his services, and it was resolved to present him with
some permanent mark of our sense of the value of those services.

A service of plate, consisting of a salver, silver coffee-pot, teapot, cream
jug and sugar basin, was then brought forward, and Mr. Bywater was asked to
accept it in the name of the Club, Mr. Durham at the same time expressing
regret for the loss of his services, and good wishes for the future. The follow-
ing inscription was engraved on the salver : —

" Presented, together with a silver tea service, to Witham Matthew Bywater,
by members of the Quekett Microscopical Club, as a token of appreciation
of his indefatigable exertions both as a founder of the Club and as
honorary secretary during four years. 1869."

Mr. Bywater expressed his deep sense of obligation to the members for this
valuable mark of their kindly feeling and esteem, and he hoped that he should
be pardoned, if his words failed to express all he felt upon the occasion. He
looked back with pride to the period during which he had been associated with

28

the Club, which had been an unparalleled success, and had astonished its most
sanguine promoters. When he first undertook the office of Secretary he told
those who worked with him that he could lay no claim to scientific knowledge,
but would give the work he had to do such attention as was compatible with
business. He regarded the past four years with considerable pleasure, for
amongst the many new associations into which he had been brought true friend-
ships had been formed among those with whom he had worked, and which he
believed would be as lasting, now that his position was altered. He should
ever regard with pride the splendid testimonial with which he had been pre-
sented, and for which he again thanked them heartily.
The proceedings then terminated with a conversazione.

In reference to the testimonial presented to Mr. By water we are requested to
add that the list of subscribers comprehended about 150 names, and that the
arrangements were carried out by a committee composed of the following
gentlemen, viz. : — Messrs. Arnold, M. C. Cooke, Curties, A. E. Durham, Gay,
Dr. Gray, Hislop, Ketteringham, Kent, Leighton, Mclntyre, W. W. Reeves,
Reynolds, and Watson.

29

The Geographical Distribution of Mosses in Europe, and

their Aspects in Nature.

By Eobert Braithwaite, M.D., F.L.S., V.P.
(Read 28th January, 1870 J

To the unobservant eye Nature discloses nothing, yet she scatters
her productions broadcast over this fair world of ours, and by the
massing of individuals, or admixture of species, stamps each locality
with its own peculiar features.

Among the plants which take part in this, and to a much greater
extent than is generally supposed, are the Mosses, and I have
thought that an outline of their geographical distribution in Europe
as given by Prof. Schimper, might interest those who do not study
them more particularly.

He divides the whole of Europe into three zones.

1st. — A Northern Zone, extending from the Arctic Ocean to
the 60th parallel of latitude, and thus including N. Russia and the
Scandinavian Peninsula, and at its western end descending to 57°
so as to take in the N. of Scotland.

2nd. — A Middle Zone, embracing all the country between the
60th parallel, the German Ocean, and the south foot of the Alps,
or a line on the 46th parallel from the outlet of the Danube to the
mouth of the Garonne.

3rd. — A Southern Zone, extending south of the last to the
Mediterranean and Black Sea.

The Northern Zone presents sufficient diversity of character as
to permit of its division into an arctic and a lower part.

In this zone about 480 species are found, but the arctic portion
has only some 160 ; the individuals however occur in such vast
numbers as to impress a decided feature on the landscape, the
Polytricha especially give a gloomy aspect to these desert regions,
only relieved by great bogs covered with Sphagna, and on the
rocks black tufts of Andre wa and hoary Grimmias.

Yet it is here that some of the rarest species reward the Bry-
ologist, and it is in such solitudes as even our own country can

Journ. Q. M. C. No. 10. d

30 R. BRAITHWAITE ON THE GEOGRAPHICAL DISTRIBUTION OP

offer in the wild mountains of Braemar and Glen Lyon, that we
indeed feel alone with Nature, and with Nature's God.

The lively green of more temperate climes is nowhere visible
among the far-and-wide spreading mosses of the Arctic Northern
Zone, yet among them are found scattered some species which
even excel in beauty those of the most favoured countries, witness
these Splachna luteum and ruhrum, which do not descend to the
most northern point of Britain, yet form a striking object in the
bogs of Lapland and N. Russia. As we proceed southward, new
species are added to the list, the trees lose their lichens, and often
support mosses, though the Sphagnum swamps are still a noticeable
feature. Besides the Splachna mentioned, we have also S. Worm-
skioldii and vasculosum, the latter reaching the Scotch mountains,
with (Edipodium, Psilopilum arcticum, a number of Hypnacea? and
Bryaceas, and various species of Andrecea and Dicranum which are
confined to the northern zone.

The Middle Zone, embracing the greatest extent of country and
the most varied surface, is also the richest in species, many of
which pass over the northern and southern boundaries into the cor-
responding zones. Six hundred species of mosses have been
enumerated in this zone, and some are characteristic of it, as several
of the Phascoid group, Anmctangium Hornschucliianum and Sendt-
nerianum, Braunia sciuroides, Tetrodontium repandum, Encalypta
longicolla and apophysata, &c.

The Southern Zone having a more elevated temperature, and
wanting the dense forests of central Europe, is less adapted to the
growth of mosses, and the list falls to 340 species ; yet the slopes
of the Pyrenees and Apennines have a rich bryological flora, and
some species' are peculiar to the Mediterranean area as Phascum
Carniolicum, Bruchia Trobasiana, Fabronia, Fissidens grandifrons,
rivularis, and Sardous, and especially a number of Trichostomaceae,
some of which, encouraged by the higher temperature of the coast,
creep up the Atlantic shore of France, and extend over to the
south of Ireland and south-west of England, and thus become
rarities in the British Flora ; of these I may mention Tortula
squarrosa, Vahliana and cuneifolia, Trichostomum flavo-virens, cris-
pulum and brachydontium, with Bryum Tozeri, torquescens and Doni-
anum, Leptodon Smithii, Daltonia splachnoides and Hookeria Icete-
virens.

For a similar reason the coast of Norway, and its parallel

MOSSES IN EUROPE, AND THEIR ASPECTS IN NATURE. 31

mountain range, the Dovrefjeld, are rich in mosses, being exposed
to the influence of the Gulf-stream, which greatly modifies the
severity of the climate. Besides this superficial distribution^ an-
other still more important is that in altitude, or range above the sea
level, and this is marked out by lines gradually descending as we
pass from south to north, until in the Arctic Zone they become
closely approximated ; in fact, the lines form arches from pole to
pole, whose highest point or crown is over the equator.

Prof. Schimper indicates five regions for the distribution of
mosses altitudinally, all of which are characterised by certain pre-
dominant species, just as they are by certain flowering plants, and
we have only to climb any elevated mountain range to find that the
plants we first met with disappear as we ascend, and are replaced by
other species, which also have their limits, until we reach the line
of perpetual snow, beyond which all is solitude and desolation, and
the crustaceous lichens even fail to maintain a footing.

Commencing at the sea level we have :

1st. — The Campestral Region, or that of the cereal plants and
fruit trees, which extends up the mountains to a variable height,
according to the latitude ; thus in the Southern Zone, on the
Pyrenees, it reaches to 3100ft. on the south side and 2100ft. on
the north ; in the Middle Zone it approaches 1400 in the southern
parts, falling to 750 and 500 at its northern limit ; in the Northern
Zone it descends so rapidly from 500 to that at 66° it disappears,
and thus in the Arctic part of this zone the campestral region is
altogether wanting.

You will observe that this region in the separate zones presents
very different conditions of surface : we have the artificial sub-
stratum of cultivated fields and roadsides, hills and woods, open
desert plains, heaths, bogs, and marshes, and all varying inter se,
according to the nature of the soil, whether calcareous or argilla-
ceous, sandy, rocky, or stony ; and according to this difference in
the chemical constituents of the soil are certain species predomi-
nant, and hence the aspects of the campestral region are in the
highest degree varied. Many mosses of this region extend upward
to the one above, from which again others descend into it. It would be
tedious to enumerate the species occurring in this region, since
they comprise all that are generally diffused over our downs and
heaths, woodland banks, and hills of moderate elevation.

2nd. — The Montane Region ascends from the cultivated region to

d 2

32 R. BRAITHWAITE ON THE GEOGRAPHICAL DISTRIBUTION OF

the upper limit of growth of the beech, and extends in the southern
zone from an altitude of 5800 to 6800ft., in the middle zone from
1400 to 3400, and in the arctic northern descends into the plain
but little above the sea level. The features of surface are dense
woods of oak, beech, and pine, stony banks of streams and rocks,
all localities congenial to a rich growth of mosses.

The most characteristic species are — Bryum crudum, elongatum
and Duvalii, Cinclidium Stygium, Amphoridium Mougeotii, Tetra-
phidacece, Bartramiacece, many Polytricha, Dicranacea and Grim-
miacece, Ulota Drummondii, Ludivigii, crispa and other Ortho-
trichaceas, Hypnum Halleri, crista-castrense, commutation, uncinatum
and revolvens.

3. — The Subalpine Region reaches from the limit of the beech
to the upper limit of the Pinus abies, or spruce fir; the beech,
when it does occur, has ceased to be a tree, and takes the form of
a shrub. The chief features are pine and birch woods, rocky
streams, bare mountain pastures, turf bogs and rocks. The rapid
streams bring down many mosses from the higher region, which
become associated with others of the region below.

In the northern zone the most characteristic mosses are — Andreosa
rupestris, petrophila and falcata, Blindia acuta, Ditrichum flexicaule
and homomallum, Distichium capillaceum, Grimmia apocarpa and
patens, Splachnum sp., Mnium cinclidioides and spinosum, Timmia.
Bartramia ithyphylla and Halleri, Oligotrichum, Pogonatum alpinum,
Polytrichum gracile, Pterogonium jiliforme, with Plagiothecium
pulcliellum and Muhlenbeckii.

4. — The Alpine Region extends above the upper limit of the
fir, and commences with the Pinus Pumilio, or dwarf pine, ending
where that ceases to grow.

In the northern zone the birch tree has disappeared, but the
Betula nana, or dwarf birch, as an erect shrub, occupies marshy
ground, and Salix Myrsinites, Menziesia ccerulea, Silene acaulis,
Diapensia Lapponica, &c, flourish abundantly. Many fine mosses
now appear for the first time, and yield a rich harvest to the col-
lector, as any who have explored the Highland mountains must
have observed.

Among our British species I may enumerate Dicranella Grevil-
leana and subulata, Dicranum falcatum, Blyttii, glaciale, &c, Dis-
tichium, Rhabdoiveisia, Grimmia many sp., Dissodon, ' Tetraplodon,
Bryum julaceum, Muhlenbeckii, polymorphum, &c, Tortula Drum-

MOSSES IN EUROPE, AND THEIR ASPECTS IN NATURE. 33

mondii, Ditrichum glaucescens, Polytrichum sexangulare, Amphoridium
Lapponicum, Encalypta commutata and rhabdocarpa, Andrecea cras-
sinervia, petrophila, alpestris and obovata, Hypnum sarmentosum,
callichroum, Bambergeri, sulcatum, &c., Myurella j'dacea and
apiculata.

5. — The Supra-Alpine Eegion, reaching above the limit of
Pinus Pumilio and Betula nana to the line of perpetual snow.

Here we have vast sterile rocks, some beaten and lashed by every
tempest, others constantly irrigated by streams from the melting
glaciers, with patches of short grass and deposits of black earth,
often mixed with detritus from the rocks above. In the middle
zone this region lies between 6,800 and 8,300 ft., in the northern
from 4,800 it descends gradually to below 2,800. Although the
line of perpetual snow does not touch our Scotch mountains, we
have snow fields more or less extensive lasting through the sum-
mer, as on Ben Nevis and the Cairngorm range, and we have some
of the characteristic mosses of this region, as Conostomum, Bryum
demissum, acuminatum, Ludwigii, and polymorphum, Pottia latifolia,
Dicranum fulvellum, Grimmia Doniana, contorta, elongata and mon-
tana, Polytrichum sexangulare, Andreosa nivalis, alpestris and
obovata, Hyp. glaciate, uncinatum, sarmentosum, arcticum, &c.

I may now say a few words on the various habitats affected by
mosses, some of which, no doubt, have come under your notice, if
only as the little Tortula muralis, which raises its fruit stalks in
serried ranks between the bricks of our garden walls, or the Bryum
argenteum and Ceratodon purpureus that overrun neglected paths.
These, however, are sufficient to teach you many points in the
structure of the class to which they belong, and they will show you,
also, that mosses are pre-eminently social plants, that they never
occur as solitary individuals, but live in densely aggregated
colonies, which unite with others of various kinds, and thus form
that verdant carpet which, as Prof. Schimper well observes, " ani-
mates with brightness the highest mountains, inaccessible to more
perfect plants, enlivens woods impervious to the sun's rays, and
protects the earth against the drying and congelation equally fatal
to vegetable and animal life." A very little observation will tell
us that certain habitats have their constant occupants, and thus an
old wall becomes a very botanic garden to the Bryologist, Such
we may term mural species, and foremost among them place the
never failing Tortula muralis, and its pretty constant companion,

34 R. BRAITHWAITE ON THE GEOGRAPHICAL DISTRIBUTION OP

Grimmia pulvinata, associated with which are Tortula revoluta,
Bryum ccespiticium, argenteum, and capillare, Hypnwm sericeum
polymorphum, tenellum, murale, &c. Roofs of outhouses, both of
thatch and wood, support Tortula ruralis, Didymodon Jlexuosus,
Ceratodon, Weisia cirrhata, &c.

Passing next to the road sides and cultivated fields, we find on
clay soil Ephemerum, and most Phasca, Pottia truncata and minu-
tula, with Tortula ambigua, unguiculata, and fallax, Physcomitrium
pyriforme and Weisia controversa; on waste ground and gravelly
commons Funaria, Ceratodon, and Bryum argenteum, and where
these are heathy Polytrichum piliferum, Pogonatum aloides and
nanum and Dicranella heteromalla.

From the mural mosses it is but a step to the saxicolous, or rock
inhabitants, for some species are common to both ; they vary how-
ever, according to the chemical constituents of the rocks, and ac-
cording to the altitude of the locality. Thus we have the silici-
colous, or those living on siliceous rocks, of which there are two
types, sandstone and granite, both widely distributed.

Sandstone rocks are a favourite site for many species, the porous
nature of its particles permitting water to percolate freely, and
allowing them easily to fix their roots. Schistostega, Seligeria
pusilla, Tetrodontium, Amplwridium Mougeotii, Thamnium alope-
curum, Grimmia apocarpa, Amblystegium filicinum and commutatum,
are seldom absent from them.

Granite, on the other hand, is more compact, yet often contains
those ledges and fissures in which so many alpine species delight
to establish themselves, numbering among them all the Andreasas,
Cynodontium polycarpum and Virens, Dicranum Scottianum, longi-
folium and hyperboreum, Grimmia, many sp., Hedwigia, Racomi-
trium, Ptychomitrium, Glyphomitrium, Orthotrichum rupestre, Sturmii
and Hutchinsice, Brachyodus, Campylostelium, A nodus, Mielich-
hoferia, Bryum alpinum, Muhlenbeckii and julaceum, Hyp. molle,
umbratum, demissum and StarJcii.

Calcicolous mosses, or those of chalk and limestone, are often
peculiar to that formation, such e.g. as Eucladium, Seligeria several
sp., Weisia calcarea and 7*iq)estris, Trichostomum tophaceum and
fiexicaule, Grimmia anodon and orbicularis, Encalypta streptocarpa,
Bartramia GEderi and calcarea, Hypnum tenellum, &c.

Another group which adds much to the enjoyment of sylvan
scenery, is the arboricolous, or those residing on living trees — the

MOSSES IN EUROPE, AND THEIR ASPECTS IN NATURE. 35

beech, willow, and larch bearing the greatest number of tenants,
among which the species of Orthotrichum hold the first place, s6me,
indeed, being confined to a single kind of tree. We have also
Cryphoea, Leucodon, Zygodon, several sp., Tortula Icevipila and
latifolia, Leskea pulvinata, Habrodon Notarisii, Neckera sp., with
many others.

The lower part of the trunks and stocks are also often coated
with a beautiful mat composed of creeping interwoven stems, the
most frequent being Stereodon cupressiformis, Amblystegium serpens
and Anomodon viticulosus.

The only other group impressing a marked feature on the
locality it occupies is the Paludal, comprising the species living in
bogs and marshes, foremost among which are the Sphagnaceas,
which in northern regions cover vast areas with their pale green
masses. Besides these, we have also Polytrichum commune, Aula-
comnium palustre, Meesia, Mniurn punctatum, subglobosum and
cinclidioides, Hyp. fluitans, and others of the aduncum group, with
cuspidatum, nitens, stramineum and cordifolium.

In illustration of some of these aspects, I place before you sheets
of specimens, in some cases with the flowering plants also with
which they were associated, the last labour of one now no more,*
who thus attempted to work out the idea of representing the flora
of each locality at a glance.

In this sphagnum tuft you notice the dense aggregation of indi-
viduals, to the exclusion of all other forms, which, with its loose
cellular texture, give it that spongy character so treacherous to all
who venture on it.

Here are sheets from the Gap of Dunloe, with the wild Saxifraga
umbrosa, or London Pride, and from Killarney, rich with Hooheria
Icetevirens, and Hymenophyllum, associated with the fine Hepaticas,
Hygrophila irrigua, Physiotium cochleariforme and Triclwcolea
tomentella.

Others exhibit the mosses and lichens from sandstone rocks
in Bridge Park, and these beautiful specimens from our friend
Mrs. C. F. White, are products of the commons about Virginia
Water. The Alpine species are represented by collections from
Ben Voirlich and Ben Lawers, the latter one of our richest
localities.

But especially I would call your attention to the universal asso-

*N. B.Ward, Esq.

36 R. BRAITHWAITE ON THE DISTRIBUTION OF MOSSES.

elation of mosses with ferns, for both delight in moisture and
shade. Here is a great tuft of Hypnum loreum from the surface
of a rock at Ambleside, and growing from its centre is the beau-
tiful fern Polypodium Phegopteris ; the moss, no doubt, was the
first occupant, and as it stretched out its tiny arms and thousand
little leaves, these detained the dust grains borne onward by the
winds, and entangling the autumn leaves, soon converted them
into rich mould ; anon the fern spore, too, is arrested in its course,
vegetates and permeates the tuft with its rhizomes, binding the
whole firmly together, and to its rocky bed.

Since mosses require but a point on which to fix themselves, and
moisture to continue their existence, no class of plants enjoys such
a wide-spread distribution, for from the eternal snows of the highest
mountains to the ocean fringe of the shore, they are everywhere
prevalent ; clasping in their slender, yet tenacious arms the
crumbling stone, or hiding, as with a mantle of youth, the pros-
trate monarch of the forest in his final stage of dissolution, and
supplying the last wreath placed by nature on the tomb of man.

How extensive, then, is the field occupied by these plants in the
economy of creation ! How eminently are they calculated to de-
light the eye, both by their exquisite structure and the part they
play in the scenery of the world around us ! Even here, though
dead, they may point our moral and adorn our tale, and they will
live for ever on painter's canvass and in poet's verse.

Testimonial to Dr. R. Braithwaite.— On Thursday evening-, February
10th, a deputation from the gentlemen who had attended Dr. Braithwaite's
Lectures on Mosses assembled at his residence for the purpose of presenting
him with a token of their esteem and regard. The Testimonial consisted of a
Silver-mounted Claret Jug, and Prof, de Notaris' great work "Epilogo della
Briologia Italiana." The former bore Dr. Braithwaite's crest, and the latter
the inscription, " Presented with a Claret Jug to R. Braithwaite, M.D., F.L.S.,
in token of the pleasure and instruction derived from a Course of Lectures on
Mosses." This was signed by all the subscribers. Mr. Bell, F.C.S., in making
the presentation eulogized the care bestowed in the preparation of the Lectures,
the clearness of their delivery, and also the hearty friendliness with which the
subscribers had been received by Dr. and Mrs. Braithwaite.

Dr. Braithwaite expressed his gratification at the kindly feeling displayed
towards him by the subscribers, and at the reception of so unexpected a recogni-
tion of his humble efforts to spread a knowledge of his favourite study.

r» :

Notes on some French Diatomace.e, Presented to the Club
by Alph. de Brebisson, Corr. Mem.

(Communicated February 25th, 1870. )

Pleurosigma JEstuarii. W. Sm. — Mortalines, near St. Vaast
(Manche). In these two preparations there will also be remarked
the Amphora membranacea, Nitzschia spathulata, and even a few
individuals of Toxonidea falcata and insignis.

Pleurosigma gracilentum Rabenh. P. Kiitzingii Grim. This ought
to be the P. Spencerii of W. Smith's Synopsis, but it is not Bailey's
species, according to his own examination.

Navicula (Pinnularid) dactylus. Ehrb. One of the principal
forms of the group which includes the Navicula or Pinnularia nobilis,
major, etc., which, doubtless, all have the same origin, as coming
from the N. viridis Ehrb. (Infus. vol. xiii., f. xvi.)

Navicula punctata (W. Arnott, in litt.) This species, which is
always mixed with many other Diatornacea?, is easy to distinguish
by the three enlargements, one of which is central, and two terminal,
all rounded, and nearly of the same volume, and especially by its
carapace covered with punctuations or rugosities, which appear to
be internal. It is this species to which I had in 1828 (" Consid.
sur les Diatom, p. 19) given the name of Frustulia acrosphceria,
but it is not the Navicula aero splicer ia of Kiitzing (Bacill., p. 97,
tab. 5, f. ii.), the summits of which are not sensibly enlarged, nor,
as some authors have thought, the Nav. tabellaria of Ehrenberg,
which has no punctuations. To avoid a confusion, which is always
to be regretted, Walker- Arnott proposed to give to this species the
name of Navicula (or Pinnularia) punctata, an opinion which I
hastened to adopt, supported by so competent an authority.

Navicula humerosa Breb. (in W. Sm. App.) This species, which
I first found at Divas, in the sandy pools of the sea shore, is pretty
common between Trouville and Honfleur in the pools or pits of
slightly brackish water with stony bottom.

It much resembles the Nav. granulata, but the valves of the latter
are more elongated, less suddenly attenuated at the summit, often

38 A. DE BREBISSON ON SOME FRENCH DIATOMACE^E.

contracted towards the middle, and charged with more pronounced
and more distinctly moniliform striae.

Navicula oculata Breb. (in Desm. Crypt., 110) First discovered
by the learned algologist, M. G. Thuret, near Lagny, in the
environs of Paris ; this species has since been collected by us near
Falaise. It is very small, linear, with rounded summits, and re-
markable by its very apparent central nodule.

Peronia erinacea Breb. and W. Arn (in Journ. Micr. Sc.)
Different characteristics, and principally the absence of a central
nodule on the valves, not permitting this Diatom to be retained
in the genus Gomphonema, where I had first placed it (see Kiitzing,
Sp. Alg. p. c g, sub. Gomph. Fibula) have determined W. Arnott and
myself to propose this new genus which at present contains but one
single species which grows in fresh water springs, on inundated
plants, and especially on the leaves of Sphagnum.

Cymatopleura apiculata W. Sm. et var. We do not think that
this Cymatopleura can be anything but a variety of C. Solea. All
the forms presented by this species pass so much from one to the
other in an insensible manner that it would be always difficult to
assign them a place in a regular series. The forms included in the
accompanying preparation are the var. apiculata and another
larger, broader, figured by Ehrenberg in his large work on the
Infusoria (t. xiii., xxii., f. 1 and 3) and which, for this reason,
I call var. Ehrenbergii. Fig. 2 of the same plate must be the
variety Librile.

Surirella Capronii. I am indebted to Mr. Fr. Kitton for the
knowledge of this remarkable Diatom. Having communicated to
him, nearly two years ago, the mixture of Surirella which had been
collected in our neighbourhood, he observed to me that, in the
midst of the numerous individuals of Sur. elegans which were most
prevalent, there was another form, the valves of which were pro-
vided on their broadest summit with a sort of spur, or salient point,
and informed me at the same time that a similar form had been
noticed in England by Dr. Capron, the naturalist, who is so often
mentioned by W. Smith as having communicated to him interesting
researches in the neighbourhood of Guildford. Dr. Capron having
been so good as to address to me a preparation of his curious
Surirella, I was able to convince myself of its identity with the
Normandy plant ; I then proposed to dedicate it to Dr. Capron.
I have since received from the clever Danish preparer, M. Moller of

A. DE BREBISSON ON SOME FRENCH DIATOIIACE^E. 89

Wedel, another Surirella, the S. nobilis or robusta, the valves of
which are also armed with a spur. It is the S. splendida (?) var.
aculeata of M. Grunow. Then, finally, I found again near Falaise,
a real S. splendida, Ehrenb., on the valves of which is also seen a
rudimentary spur. This appendage is not, therefore, an essential
characteristic, on which we can establish a distinction of species,
but only an accidental state, the result of a superabundance of silex
in a certain point of the carapace of these Diatoms. Often in
such a case, a collection of the siliceous matter, the secretion of
which forms the envelope of the Diatornaceaa shows itself on the
middle of the valves, in the form of a kind of cord, or medial nerve.
This line, strengthened, may remain straight and salient, in con-
sequence of rupture in the point where the valve bends suddenly,
especially at the broad and rounded extremity of the cuneiform
frustules ; at the other summit, which is narrower and less curved
inwards, it is rarer to meet with such a spine-shaped appendage,
although this anomaly is sometimes met with there.

The Surirella biseriata, which is also in these preparations, having
no decided curve at the summits of its valves is never furnished
with spurs. Nevertheless, this Diatom, although its envelope is
not cuneiform, is probably, like the preceding, only a modification
of one and the same type.

Surirella linearis, W. Sin. and Sur. amphioxys, W. Sm. In
examining the different forms which are found mingled together in
these preparations, we might be tempted to believe that the draw-
ings given by W. Smith were made from a similar collection.
Several authors, and W. Smith himself, have remarked that the
figures 58a, a 1 and b 1 of the synopsis (t. 1., pi. viii.) belonged to
at least two species. In these preparations may be recognised
individuals which ought to be referred to the Sur. pinnata, the
S. panduriformis, and even to the S. angusta, which would assign
to all these forms one and the same point of departure, an hypo-
thesis which is very admissable.

Surirella crumena Breb. (in litt. ad Kiitz., 1844, con. spec.)
Cyclotella Meneghiniana (3. major Spec. Alg. p. 19. Surir. Bright
wellii, W. Smith, syn. i., p. 33, pi. ix., f. 69.(?) Fresh and brackish
waters, Calvados, Geneva, Montpellier, etc. Misled by a form of
Sur. subsalsa with large valves and rounded, which I refer to fig.
G9, pi. ix., of W. Smith's Synopsis, I thought that as this figure
represented >,he type of *S*. Brightwellii this species ought to be

40 A. DE BEEBISSON ON SOME FRENCH DIATOMACE.E.

different from my S. crumena ; thence came the observation I ad-
dressed to W. Smith, which determined him to announce in a note
to his 2nd vol., p. 89, that I had recognised characteristic differ-
ences between S. crumena and S. Brightwellii. Since then I have
had numerous specimens from England, from W. Smith himself,
from W. Arnott, and M. G. Norman, which have convinced me
that it was one and the same species. Only it is possible that W.
Smith's figure, quoted above, ought to be referred to a form with
large and rounded valves of S. subsalsa. This latter species is
especially distinguished by its inferior summit of the valves, which
is attenuated and considerably hollowed into a gutter, and by the
presence of applied wings, but these are raised and more apparent
near the summits. The valves are also generally oval, while in the
crumena they are nearly always circular, and so much so that
Kiitzing in his Spec, Alg., p. 19, thought proper to unite this
species to his Cyclotella Meneghiniana as variety /3. major ; a con-
nection which it is difficult to understand, if we remark the double
direction of the canaliculi which converge towards two diametrically
opposite points of the circumference, the two summits {Pali Rab.)
instead of radiating regularly in the direction of one centre, as is
the case in the Cyclotella.

Surirella minuta Breb. (in Kiitz. Spec. Alg.) although this
Diatom is always smaller than the ovata, that its colour is darker,
more blackish, and that its figure is different, it is very probable
that it is only a form of S, ovata to which ought to be united also
a certain number of pretended species which are common in
brackish waters.

Nitzschia Brebissonii W. Sm. syn. i., p. 38 (exclus. synonym).
I had no right to the honour of this dedication, which must be
accepted in order to avoid rendering the synonymy inextricable.
This species, from brackish waters, differs completely from Sigmatella
Brebissonii of Kiitzing, which inhabits fresh water, and is only a
broad and but slightly sinuous variety of Nitz. sigmoidea, a variety
which may be called Armoricana in order to avoid a source of
errors. It was the Synedra Armoricana of Kiitzing (Bacill, tab. 4,
f. 34.)

Nitzschia obtusa W. Sm. (syn. i., p. 35, pi. xiii, 107.) Pools
of brackish water near Trouville. This species is found in abundance
in the midst of the filaments of algse which carpet the surface of
the pools. It Was thought that the filaments had originally con-

A. DE BREBISSON ON SOME FRENCH DIATOMACE^. 41

tained the frustules, which would consequently have belonged to
the genius Homeocladia. This opinion was the result of an in-
complete observation. These felted layers supplied the diatom
with an accidental station, but were not a part of their indi-
viduality.

Nitzschia gracilenta Grun. in. litt. Found in November, 1868,
in pools near Falaise, on a clayey soil.

Fragilaria virescens Ralfs. Remarkable in this state on account
of its numerous sporangiferous articles, half as long again as the
frustules, which are disposed in series, and present the most varied
forms.

Eupodiscus Gregoryanus. Breb. MSS. Cherbourg. This
species is probably Eup. subtilis of W. Gregory, (Diat. Clyd., p. 29,
tab. iii., f. 5.) but it may be doubted, for the figure indicates a
kind of central nodule, and does not mention the series of small
protuberances (processes ) which are placed near the edge of the
valves. It is this species which was first indicated by W. Smith,
under the name of Coscinodiscus concinnus. It cannot be referred
to Ehrenberg's Coscinodiscus concinnus, and therefore it seems to
me better to give it a new name.

Eupodiscus Roperii Breb. MSS. Coscinodiscus ovalis. Rop.
This species, like the preceding, ought to belong to the genus
Eupodiscus. Its texture is the same, and its valves also bear, near
their edge, a row of small protuberances or salient appendices
(processes), which have no communication with the centre by
means of radiating lines, as in the genus Aulacodiscus.

This is certainly Roper's Coscinodiscus ovalis (Journ. Micr.
Sc, vi., p. 3, f. 4.) In truth, in the figure given (i.e.), the inter-
marginal processes are not indicated, and they may have escaped
the draughtsman's observation if he had under his eyes a balsam
preparation, as this renders these organs too transparent.

This species, and the preceding, ought to belong to the genus
Cestodiscus, founded by Greville. — (Trans, of Micro. Soc, N.S.,
vol., xiii., p. 48.)

Cyclotella rectangula Breb. (Cycl. operculata /3. rectangula
Kiitz. Spec. Alg., p. 19.) — I first collected this Diatom near
Lagny, in the environs of Paris, and we have since found it
around Falaise. It differs much from Cyclot. operculata ; its valves
are plane and not undulating ; their contour is strongly marked
with points or dimples which are very apparent, even on the very
squarely angular edge of the frustules (front view).

42 A. DE BREBISSON ON SOME FRENCH DIATOMACEiE.

Biddulphia loevis Rop. Found at Divas (Cotes du Nord) at the
mouth of the Ranee, at a few leagues from St. Malo. It has also
been seen in the neighbourhood of Careutan.

Epithemia succincta Breb. I discovered this Diatom in June,
1852, at Ouistreham, at the mouth of the canal, which was not
then open to navigation. It was growing mixed with Epith. sorex
and ventricosa, on the floating debris of senii-deconiposed Ulvacese.
I named it Epith. constricta, and I offered it, under that name, to
W. Smith, who was travelling through our country at that time.
Occupied at that time with the publication of the first volume of
his fine work on the English Diatomacese, he inserted Epithemia
constricta., and figured it in one of his supplementary plates. The
drawing was not made from my specimens, but from a different
plant of the same. Always seeking to avoid causes of error, I
have abandoned the name of constricta to Smith's species, and have
called the Ouistreham one Ep. succincta. It is much smaller than
the former ; its lateral indentation is also less decided. This
strangulation might be only accidental, and not furnish a really
distinctive character fit to establish a species. The Epithemia
gibberula, so common in the Mediterranean, sometimes presents a
kind of analogous indentation.

M. Pedicino has figured this state of E. gibberula, figs. 10, 20, and
23 of plate 1 of his work on the Diatomaceaj of the thermal waters
of the Isle of Ischia.

Note. — The preparations mentioned in the foregoing communi-
cation having been submitted to Mr. F. Kitton for his opinion,
elicited the following observations : —

" I do not see much to add to M, de Brebisson's remarks. I
would suggest that the specific name of Navicula punctata be
changed, as we have already a Navicula punctulata. I should,
however, prefer retaining the genus Pinnularia, and referring to
that genus all forms with costate markings. The following are the
synonyms of this form : — Pinnularia tabellaria, Synopsis of
British Diatomaceee — the longer form of the same species,
P. acrosphceria of the same work. In a communication from
Dr. Arnott he says — ' I send you slide of P. tabellaria, true, from

A. DE BREBISSON ON SOME FRENCH DIATOMACEJ3. 43

Wales, agreeing exactly with Smith's in his slide in the Brit. Mas. ;
his P. acrospharia turns out to be the longer form of the same seen
also here, but most common in the Premnay peat.' I am afraid that
the spines of Surirella Capronii are of no scientific value, and if
not this form must be referred to S. splendida.

" Eupodiscus Gregorianus is the Eupodiscus subtilis of Gregory.
It is not a true Eupodiscus, but one of the forms of Actinocyclus
Ehr. ; the marginal spines are not peculiar to this genus, and are
of no generic or specific value ; they may be observed in other
genera, notably in Cyclotella rotula. This form is not the same as
Coscinodiscus concinnus of Smith, which is a true Coscinodiscus,
with delicate hexagonal cellules. It is common in the stomachs of
Noctiluca.

tl E. Roperiana is identical with Coscinodiscus ovalis. My re-
marks on the preceding species apply to this form. It seems to
me to belong to the genus Actinocyclus rather than Eupodiscus or
Coscinodiscus.

11 One of the slides marked for Eupodiscus Gregorianus does not
contain that form, but is the same as the Navicula punctata slide.
I enclose a slide of Navicula punctata (from the Premnay peat)
for the Club.

" F. KlTTON."

Fig.

1.

Fig.

2.

Fig.

3.

Fig.

4.

Fig.

5.

Fig.

6.

Fig.

7.

Fig.

8.

Plate I.

Surirella Capronii— the form found at Shere by Dr. Capron X 300

diameters.
Surirella Capronii — as found by M. de Brebisson at Falaise X 300

diameters.
Longitudinal section of valve of the same species X 300 diameters.
Navicula punctata X 600 diameters.
Navicula oculata X 600 diameters.
Cyclotella rectangula X 600 diameters.
Epitliernia succincta X 600 diameters.
Peronia erinacea X 600 diameters.

All the above figures drawn from the slides by H. F. Hailes, V.P.

u

The Crystallization of Hippuric Acid.
By T. Charters White, F.K.M.S., Hon. Sec.

( Read December 17th, 1869.)

In introducing this subject to the Club it will be necessary to call
briefly the remembrance of the members to one or two facts fami-
liar to all,

When any soluble substance is dissolved its ultimate atoms are
distributed throughout the solvent, and provided the solvent is
prevented from evaporating, both solvent and substance remain in
the same relation, which is simply that of the most perfect
mechanical mixture known, each atom of the substance being im-
prisoned in a coating of the solvent.

Should, however, the solvent be allowed to evaporate, this rela-
tion is disturbed ; the substance, if crystallizable, such for instance
as Hippuric Acid, is set free to obey certain laws inherent in all
salines of forming bodies of definite shapes or crystals ; if this
process is allowed to take place slowly we get natural crystals of
the salt operated on ; but if crystallization is forced by evaporation
at high temperature the solvent is dissipated before the attraction
of cohesion of salt can exert its power, and the result is the for-
mation of an amorphous mass, or if we are dealing with a small
quantity on a glass slide we have a semi-transparent film. The
attraction of cohesion of Hippuric Acid acts so readily that no
rapidity of evaporation of a hydrous solution can result in any but
the natural needle-shaped crystals; we must, therefore, find sol-
vents of greater volatility, and those from which I have obtained
the best results are the strongest and purest spirits of wine I could
procure, and the ordinary methylated spirit which, containing a
little varnish, seems to act as a retarding agent in the formation
of the crystals, so that they are formed more slowly ; but even
with these solvents every care must be taken to promote the
most rapid evaporation by warming the slide, the dipper, and
the solution, if we would be successful ; the film is then evenly

T. C. WHITE ON THE CRYSTALLIZATION OF HIPPURIC ACID. 45

spread, the attraction of cohesion is locked up, but it soon strug-
gles to be free, and by the absorption of moisture from the atmos-
phere it regains its power, and dots of circularly forming crystals
begin their growth all over the film. This result can be obtained
more quickly by holding the slide a little distance above a lamp,
or it may be varied by breathing on it, or by alternating each of
these processes, or even by alternately heating and cooling the
slide at a few seconds interval ; by these means Hippuric Acid
may be made to assume an indefinite number of concentric forms,
which under the polariscope exhibit a gorgeous play of colours. •

One striking variety occurs if the crystals are formed at a tem-
perature above 800° ; the crystals then become somewhat of the
natural circular form, but arranged spirally without going through
the usual preliminary film, and they do not display much colour
under polarisation. These are interesting in relation to the ten-
dency of some salts to crystalise spirally at high temperatures.

The slides most interesting are those formed at a temperature of
about 100°; they will present the most beautiful and varied forms
of this Acid, and will furnish crystals that will be much admired
either under dark ground illumination or polarised light. Although
I have exhibited slides of Hippuric Acid upon one occasion at an
extra meeting, I thought it would be as well to bring the subject
forward at an ordinary meeting when we have a larger attendance,
and when I could receive suggestions from others who have given
more attention to the subject of crystallization generally, and when
I could answer any questions that might be put to me relative to
this Acid and the method of preparing this favourite slide for the
polariscope. This must be my apology for bringing forward so
elementary a paper on this occasion.

Extra Meetings. — Members of the Club are reminded of the
Extra Meetings, which take place on the Second Friday evening in
each month, at Seven o'clock. They are devoted to the exhibition
of objects, and general conversation on microscopical subjects.
During the Excursion season the results of the previous excursion
generally contribute to the interest of these meetings.

Journ. Q. M. C. No. 10. e

46

Observations on the Structure of the Cornea op the Bee.

By B. T. Lowne, M.R.C.S.

{Read February 25th, 1870.)

I have lately been engaged in making some sections of the cornea
of a large Carpenter Bee from South Africa, which have resulted
in my making out several very interesting points of structure.

On referring to my account of the cornea of the fly,* you will find
I have described it as consisting of two layers — an external continuous
with the external layer of the integument, perfectly transparent,
and apparently structureless ; and an internal thicker layer, sculp-
tured into facets, or rather into numerous bi-convex lenses, set in
a hexagonal framework. This layer, which I believe is continuous
with the middle layer of the integument, is too thin in the fly for
its structure to be readily made out ; nor have I attempted to in-
vestigate it.

The section which Mr. Hislop is kindly exhibiting for me is a
vertical section of the cornea of the Carpenter Bee already alluded
to, and I have found that it confirms what I have said regarding
the cornea of the fly. The external layer is far thicker than in the
fly, although it presents no trace of structure. It follows the con-
tour of the facets on the surface of the deeper layer.

The deeper layer consists of numerous thin laminse, each being
composed of a vast number of parallel fibres. It further apj)ears
to consist of hexagonal prisms, vertical to the surfaces of the
cornea, and to the laminre of which it is composed. These prisms
are not, however, separable ; although the laminas and the fibres of
which they are composed are easily separated by treating the sec-
tion for a short time with a solution of caustic potash.

The surfaces of this deeper layer of the cornea may be seen to be
covered with convex facets, a facet corresponding to either ex-
tremity of each vertical prism, the external facets being, however,
best marked.

* Monograph on the Anatomy of the Fly.

B. T. LOWNE ON THE STRUCTURE OF THE CORNEA OF THE BEE. 47

In section this layer is seen to be marked by several hundred
crenated lines, caused by the lamina? of which it is composed ; the
crenations follow the contour of the facets, the middle layers being
almost or entirely without crenations.

These lines, as well as the indications of the division of the
cornea into hexagonal prisms, are best marked in the external
portion of the layer. Numerous minute nuclei appear between
the laminae.

When viewed by the aid of polarised light and a selenite,
these modifications of structure all become beautifully apparent.
Both layers of the cornea polarise, and the colour of the transmitted
beam varies from red to green, according to the thickness of the
section simultaneously in both.

As I have already stated in my work on the fly, the mesoderm
varies very considerably in its structure. I therefore see no reason
to doubt the correctness of the views I have already published with
regard to the nature of the cornea in insects, whilst the choroid or
pigment layer, as I have stated in the same work, appears to cor-
respond to the end ode rm, or innermost layer of the integument.

If these homologies be correct, the eyes are undoubtedly integu-
mental organs, with the nerve structures situated between the two
inner layers, the principal seat of the terminal loops of the nerves
of ordinary sensation.

Excursions for 1870.

The attention of Members is specially directed to the notice, on
the cover of this Journal, of the arrangements which have been
made by the Excursion Committee for the coming season. It will
be observed that during the summer fifteen meetings will take
place, seven of which are arranged to fall within the next three
months. The first trip will be to Wandsworth Common, which
will inaugurate the excursions, on April 2nd, and it is earnestly
hoped that a large number of the Members will be found at Clapham
Junction on the day named, at three o'clock. The other fixings
are for Barnes, Wimbledon, Carshalton, Chiselhurst, Elstree, and
Hampton Court. The Excursionists' Annual Dinner, now become
an institution of the Club, is down for the 23rd of June, further
arrangements for which will be duly announced.

e 2

48

Microscopic Moulds.

By M. C. Cooke.

(Bead March 25th, 1870.)

It would be impossible, within the short space of time allotted for
the reading of a paper, to give a satisfactory outline of the num-
erous genera and species which are included in the term " Micro-
scopic Fungi." Since the establishment of the Club I have several
times been solicited by individual members to read such a paper,
and hitherto have hesitated in accepting a responsibility which I
saw no prospect of satisfying. At length a modification has been
resolved upon, and what I could not hope to do for the whole, I
am about to attempt for a part. Of the six families into which
Fungi are usually divided I have selected the Hyphomycetes ; but
before commencing with them it will be advisable to recount the
features which characterise these six groups or families. It will be
borne in mind that four of these families are sporiferous — that is,
the fruit consists .of naked spores — and that the other two fami-
lies are sporidiiferous, or the fruit consists of sporidia enclosed in
asci. Of the latter, one family consists of Moulds, which in habit
and appearance are often analogous to those we are about to con-
sider, but with a more complex fruit. The other family contains
the Spha?ria? and their allies, or the Pyrenomycetes as they are
sometimes termed, and the Pezizce and their allies, or the Discomy-
cetes. The majority of these are very minute, and may be truly
called Microscopic Fungi, but the 800 British species of ascigerous
fungi is far too large a group for such an occasion.

Passing to the Sporiferous Fungi, we have the large forms, of
which the mushroom may be taken as a type ; the Hymenomycetes
in which the hymenium, or surface which bears the spores, is exposed,
sometimes spread over plates or gills, sometimes lining tubes,
sometimes covering teeth or spines, but mostly bearing the naked
spores in groups of four at the apex of sporophores, or special
supports, on which they are seated upon little spicules. We have

M. C COOKE ON MICROSCOPIC MOULDS. 49

again about nine hundred species of these, and scarcely one which
can be called microscopic.

The next family is characterised by having the hymenium, and
consequently the spores, enclosed in an outer covering, or peridium.
Such for instance are the puff-balls. These are called Gasteromy-
cetes because of this character. Mixed with the spores threads are
sometimes developed, and in some cases the spores are formed upon
these threads. In the Myxogastres the relation which subsists
between the threads and the spores has not been satisfactorily
determined. Amongst the most interesting genera in this family
are Trichia and Arcyria.

The remaining two families are truly microscopical. The
Coniomycetes, to which the greater part of my volume on u Micro-
scopic Fungi " is devoted, and the Hyphomycetes, to which our
attention is presently to be directed. The first of these has
the spores as the most prominent feature, and the latter the threads
upon which the spores are borne. The "smuts" and "brands"
may in some sense be taken as the type of one, and " blue mould "
of the other. It is only partly that the common objects I have
named can be regarded as types of the two families, because they
only represent in many of their features a section of the family.
The " smuts," for instance, cannot be accepted as a representative
of a Diplodia, in which the spores are enclosed in a distinct peri-
thecium, and is a sort of Sphooria without the asci ; nor of such
a genus as Excipula, which is pezizceform, but without the com-
pound fruit.

Not to weary you with technicalities, or by indicating analogies
between forms which I may assume are unknown to the majority
of the members, I will proceed to describe the general structure
which prevails in the Hypthomycetes, or Moulds, hoping that those
who are familiar with the subject will, for the sake of those who
are not, censure me gently if my observations should seem to be
too elementary. There could be no stronger evidence of the small
interest which microscopists generally take in this subject than the
fact that in a club of five hundred members it was nearly two years
before a sufficient number could be induced to unite in the forma-
tion of a class for the study, or to obtain the preliminary infor-
mation necessary for the study, of these neglected organisms.
Perhaps in no country in Europe, with equal advantages, are
fungi so little known or studied as in Great Britain. There is

50 M. C. COOKE ON MICROSCOPIC MOULDS.

evidence of this if we compare our own literature with theirs.
The splendid works of Corda and Tulasne have no counterpart
with us, except in the less ambitious Cryptogamic Flora of the
late Dr. Greville, and the forty years' unrequited labour of the Rev.
M. J. Berkeley.

If we examine the decaying stems of herbaceous plants during
the winter or in the spring, it will not be long before we discover some
grey mould flourishing in patches, and giving off a cloud of spores
directly it is shaken or roughly handled. Just such a mould as I
have in my mind's eye I have found in little* tufts on a decaying
portion of the outer husk of the fruit of the Horse Chestnut. This
mould always ^ grows in tufts, visible to the naked eye, like a
miniature tuft of grey wool ; but if we employ a pocket lens for
closer examination, that instrument will be sufficient to reveal to
us a tuft of shining, dark coloured threads or flocci, supporting
clusters of little white spores. Even such an examination, imper-
fect as it is, cannot fail to impress the observer with the beauty
of the object ; but if we employ successively a microscope with a
two-inch, a one-inch, and a quarter-inch objective, by dint of
patience and perseverance we shall be able to make out the entire
structure delineated in the diagram. (Plate vi.) This mould is
known as Poh/actis fasciculata, and was first figured and described
by Corda in his " Prachtflora." The tuft of flocci or threads is
connected at its base with, and springs from, a reticulated mass of
delicate branched creeping filaments, which is called the mycelium.
This mycelium corresponds to the root of a plant, of which the
erect flocci represent the stem, giving off branches and bearing the
fruit in the form of clusters of spores. Fungi, in all the families,
more or less possess a mycelium ; it is the base of the vegetative
functions of the plant, and however much the complete fungus
may differ from others, there is a greater similarity in the character
of the mycelium than in any other organ. Sometimes it happens
that only a mycelium is produced, growth being checked, and de-
velopment going no further. At other times barren threads spring
from the mycelium, but produce no fruit. In both such instances
the plant is imperfect, and it can only be guessing to say what
species it might have been had it matured itself. Persons who
know nothing of fungi are apt to jump to the conclusion that
Mycologists can or ought to be able to give some name for the
mycelium or barren threads of any fungus which is put into their

M. C. COOKE ON MICROSCOPIC MOULDS. 51

hands. This is demanding more than it is reasonable to expect;
and yet there are some who think that mycelium threads, or even
joints of such threads, found in different parts of the human body,
accompanying certain forms of skin or other diseases, deserve a
name and a character, although all the threads and cells ever yet
found in such positions may or may not be elementary conditions
of some very common mould, such as Aspergillus glaucus. The
flocci, or erect stem-like threads, which proceed from the mycelium
in the Polyactis are coloured, whilst in most of the true Mucedines
they are colourless. At certain distances these threads have trans-
verse septa throughout their length, and in the upper portion they
are branched, the ultimate ramuli or final branches, bearing terminal
clusters of spores. When the spores fall away little points or
minute spicules are visible to which the spores were attached.

I must beg of you to compare together all the figures before you,
and, apart from the mycelium, to recognise the features in which
they agree. Of course all of them have fruit or spores ; that is
the one essential of a perfect plant. A fungus may consist of
nothing more than a delicate mycelium and a spore, but without
the spore — the great essential — it is an imperfect fungus, and can-
not be accurately determined. The most important organ, then, in
the determination of fungi is the spore. Young students are cau-
tioned against attempting to find a name for fungi if they cannot
first of all find the fruit. In the figures before us we have the
spores borne upon threads, which may be very short, almost obso-
lete, as in Macro spo rium ; or fully developed, but unbranched, as in
Aspergillus ; or branching as in Polyactis, and many others. Here
we have the features of the family to which these moulds belong —
' Filamentous,' or thread-like, ' the fertile threads naked,' or
exposed, ' simple or branched, bearing the spores at their apices.'
It will be noticed that the spores are not enclosed, two or more of
them together in a vesicle, as in the fungi of a similar habit be-
longing to the Physomycetes, and this is the only caution needed,
for the thread-like form with terminal spores is not met with
in any other family.

" Moulds " is a term, then, which I desire you to accept on this
occasion as representing the family name of Hyphomycetes, and as
including all those filamentous fungi which bear naked spores at
the apex of simple or branched threads.

Instead of going to the woods for a second example, let us take

52 M. C. COOKE ON MICROSCOPIC MOULDS.

a little common paste which has been exposed a few days, until the
surface has become covered with a ropy film. If we try to spread
a little of this paste upon paper we are soon convinced of its ropi-
ness, and the microscope reveals the cause. The surface of the
paste is covered with an interwoven layer of mycelium. It is
clearly the mycelium of a fungus, but whether it is a mould or
not, however much we may guess, nothing can be known. In the
course of two or three days discoloured patches — yellow, blue, or
green- — make their appearance. Tufts of woolly threads, some
barren, and like little tufts of cotton wool ; others of a denser
nature laden with minute spores. Everybody calls it " blue mould,"
and there nearly everybody is content to leave it unmolested, so
far as any insight into its structure is concerned.

Under a low power a tuft of this " blue mould " appears as a
forest of delicate white threads, with a brush-like tuft of spores at
their apices, and under a still higher power the white threads
are observed to be jointed or divided by transverse septa, and in
the extreme upper portion subdivided into a fascicle, or bunch of
short delicate branches, which tend upwards at an acute angle, and
are terminated by necklaces of spores, attached to each other like
beads, and thus forming a kind of inverted tassel of spores, con-
cealing the branches of the threads, so that nothing is seen but the
simple stem and its tassel. When the spores fall away the branches
are distinctly visible. This is one of the fungi to which the name
of " blue mould" is given, but as that name is also applied to other
moulds, we must perforce employ for the future a less ambiguous
term. There is a Latin word which" represents very well the ap-
pearance this little mould possesses. It is Penicillium or Penicillum
— a "■ painting brush," from whence we derive the word pencil, as
applied to an artist's brush. The tuft of spores surmounting the
simple stem, like the tuft of hairs in a brush inverted, is well re-
presented by the generic name Penicillium. In speaking of this
mould, therefore, we must speak of it as a Penicillium, since Asper-
gillus glaucus, the " blue mould" of cheese, and other substances,
is liable to be confounded with it if the term " blue mould" is em-
ployed.

The Penicillium, and especially this species, Penicillium c?*usta-
ceum, is one of the most common of moulds. Most of us have
some knowledge of a curious, interesting-looking production which
is called a "vinegar plant," something like a piece of dirty,

M. C. COOKE ON MICROSCOPIC MOULDS. 53

sodden wash-leather, which, being placed in a saccharine solution,
induces acetous fermentation, and converts the solution into a sort
of Robinson Crusoe apology for vinegar. So long as there is
plenty of nourishment the mycelium, of which this production is
composed, continues to grow rapidly, but it does not advance
beyond that stage ; it vegetates, but it produces no fruit. The
conditions being altered, it sends up threads which bear neck-
laces of spores, and the "vinegar plant" proves itself no other
than Penicillium crustaceum. Ropey vinegar and ropey wine are to
be traced to the same source. For experiments in examining and
mounting moulds this is one of the best, since it can easily be ob-
tained in an almost unlimited supply at almost any season of the year.

We pass on now to the other "blue mould," which differs
materially from the Penicillium in the structure of the heads. It
is found on all kinds of decaying vegetable and animal matter,
and is about the same size. To the naked eye, perhaps, very
similar, unless that eye is an experienced one in detecting moulds.
The threads are simple absolutely ; that is, they are not branched
at all at the top, as in Penicillium, but instead thereof the top of
the stem is inflated into a little globose head, and necklaces of
spores are seated upon, and radiate in all directions from this head.
This is Aspergillus glaucus.

If a tuft of this mould be placed in a drop of water, on a glass
slide, and submitted to the microscope the spores will be seen ad-
hering more tenaciously to the apex of the thread than in Penicil-
lium, especially those which are seated directly upon the swollen
tip. The grumous gelatinous appearance of the head supplies a
sufficient reason for this adherence. In another species, closely
allied, elongated slender sporophores intervene between the head
and the chains of spores.

Plates iv., v., vi., vn., vin.

(Continued at page 61.)

54

PROCEEDINGS.

December 17th, 1869 — Chairman, Dr. R. Braithwaite,

F.L.S., V.P.

The following donations were announced : —

" Land and Water " from the Editor.

" Science Gossip" the Publisher.

Two Nos. " Chemical News" the Editor.

"Eeport of Excursions" ... -v

" List of Members of the Geologists' Association" f the Geologists'

" The Chief Forms of Cephalopoda," by Eev. Thos. C Association.

Willshire ... ... J

One slide of supposed Skin of Man from the door of

the Pyx Chamber, Westminster Abbey Mr. H. F. Hailes.

The eleven gentlemen proposed at the last meeting were ballotted for and duly
elected.

Mr. B. T. Lowne gave a short resume of some of his work during the past
year upon the Anatomy of the Fly, and entered chiefly upon those questions
relating to its metamorphosis, which his observations had contributed to
solve.

The Chairman, in tendering a vote of thanks to Mr. Lowne, expressed bis
own gratification at the able manner in which the subject had been treated,
and complimented Mr. Lowne upon the issue of his new work, which he con-
sidered to be one which did great honour to the Author and to the Club of
which he was a member.

Mr. Mclntire made a few critical observations upon the paper recently pub-
lished by Dr. Piggot upon the Markings on the Podura Scale.

Mr Lowne was of opinion that the scales consisted of two layers, and that
although he had never examined the Podura Scale, yet from analogy he was sure
the layers existed.

The Chairman announced that Mr. Sterne, President of the Liverpool
Microscopical Club, was present at the meeting.

Mr. T. C. White read a short paper on the Crystallization of Hippuric Acid.

The Secretary read a letter just received from America, the writer of which
asked the Club to furnish him with a first-class microscope to aid him in his in-
vestigations upon the growth and habits of the cotton worm.

The Chairman thought that the funds of the club were not sufficiently
flourishing to enable them to comply with the request.

The Secretary called attention to a beautiful specimen of Photographic
Printing by the Albertype process, lent for exhibition by Mr Groves. He also
stated that Mr. Groves had again communicated with Herr Albert as to the
price of the prints, and found that the amount ho had stated at the previous
meeting was quite correct.

55

The following objects were exhibited : —

Crystals of Hippuric Acid (with spot lens) by Mr. White.

Scales of Macrotoma Major, to show the beaded ap-
pearance which is the foundation of the new
views of structure of the Podura Scale Mr. Mclntire.

Chigoe (Pulex penetrans) Mr. Groves.

Dissection of capsules of Funaria hygrometrica, ... Mr. Smith.

Various crystals (by polarised light) ... ) j£ r> Q roves .

An Albertype Portrait ... 3

The New Calliper Eyepiece Dr. Matthews.

January 28th, 1870 — Chairman, P. Le Neve Foster, Esq.,

M.A., President;

The following donations were announced : —

11 Land and Water," weekly ... from the Publisher.

" Science Gossip " thePublisher.

" The Monthly Microscopical Journal " ... ... thePublisher.

" The Popular Science Review " thePublisher,

" The Chemical News " ... Mr Suffolk,

The following gentlemen were ballotted for and duly elected : — Mr. Wm.
Atkinson, Mr. Wm. John Bull, M.A., Dr. Ed.Dowson, Mr. T, L. Edmunds, Mr.
Peter Gellatly, and Mr. Nathaniel E. Green.

Dr. Robt. Braithwaite, P.L.S., read a paper <l On the Geographical Distribu-
tion of Mosses in Europe," the subject being illustrated by a large and interest-
ing collection of dried specimens.

The President suggested that a hearty vote of thank s be presented to Dr.
Braithwaite for his kindness in coming forward to supply the want of a paper,
by reading what the club had been favoured with that evening, which was
carried by acclamation.

Mr. B. T, Lowne said that at the previous meeting he had referred to Mr. Ray
as " the late Mr. Ray ;" he had since found that the gentleman in question was
alive, and it was therefore due to him that he should be unburied again.
The following objects were exhibited : —

Diamond Beetle from China , by Mr. Golding.

Foot of Dytiscus, and Gizzard of Cricket Mr. Conder.

February 25th, 1870— Chairman, P. Le Nev© Foster, Esq,.,

M.A., President,

The following donations were announced : —

" Science Gossip " from the Publisher.

" Land and Water " (weekly) the Editor.

" The Monthly Microscopical Journal " thePublisher,

"The Proceedings of the Bristol Natural History -\

Society " ... > the Society.

List of Members of ditto J

Two Slides Mr. Conder.

The thanks of the club were voted to the donors.

56

The following gentlemen were ballotted for and duly elected :— Mr. William
James Diss, Mr. Peter Gray, Mr. Henry J. Gray, Mr. W. H. Huddleston,

F.G.S., J.P.

Mr. M. C. Cooke read a translation of a paper entitled " Critical Notes on
British and Normandy Diatoms/' by Mons. Alphonse de Brebisson, correspond-
ing member.

The President, in inviting remarks upon the paper, took the opportunity of
expressing his opinion that the members of the club did not usually enter upon
the discussion of the papers read before them as warmly as could be desired.
Sometimes, no doubt, this might be due to a want of the knowledge of the title
of the paper which was to be brought under their notice ; but upon the present oc-
casion, a month's notice having been given of the subject, he hoped that some of
the gentlemen present had come prepared to favour them with a few observa-
tions upon it. Long set speeches were not wanted, but easy conversational
remarks would be quite suitable, and would add much to the interest and in-
formation of the meeting.

Votes of thanks to the writer and the reader of the paper were then carried
unanimously.

Mr. B. T. Lowne favoured the meeting with some observations upon the
Cornea of the Bee— the result of some recent dissections of the eyes of a large
African species of the Carpenter Bee.

A cordial vote of thanks was given to Mr. Lowne for his communication.

The Secretary called the attention of the members to a number of varieties of
Triceratium on a slide prepared from Jutland cement stone, which was exhibited
in the room by Mr. Golding ; a diagram of the diatoms referred to was also
exhibited.

Mr. M. C. Cooke said that although he was not learned in diatoms and never
professed to be, yet during the last day or two he had been interested in the
forms found in the Jutland deposit, from having to prepare some figures for pub-
lication, and he might mention that his friend Mr. Kitton, of Norwich, had
promised them an almost exhaustive paper upon the subject. He thought that
Mr. White was a little in error in referring all the figures in the upper row of
the diagram to Triceratium; there appeared to him to be several distinct
species, one being identical with Trinacria excavata, and another with Trinacria
.Reamer (plate ii) . Those in the lower row were Polycistina.

The Secretary intimated that Mr. Lowne intended to commence a class for
the study of Microscopic Zoology, beginning with the Protozoa. The class
would meet on Tuesday evenings, at Dr. Power's room in Red Lion Square, the
first meeting to take place on Tuesday, March 1st, if a sufficient number of
members were enrolled.

TUe following objects were exhibited : —

Various Crystals ( Sugar of Milk, Asparagine,

Salicine, &c.) by Mr. W. J. Brown.

Section of Human Tongue (by polarised light) ... Mr.W. Hainworth.

Diatoms from Jutland Cement Stone Mr. T. C. White.

Various Corallines Mr. Golding.

Crystals of Bichromate of Ammonia ... -\

Sections of the Eye of a Bee (in illustration of ?■ Mr. W. Hislop.

Mr. Lowne's paper) J

The President announced that the Excursion Committee had been appointed
that evening, and it would be very desirable that any gentlemen present who

57

knew of suitable localities to which excursions might be made during the
summer, should send in the names of such places as early as possible to the
Secretary.

Dr. Braithwaite expressed his willingness to assist any gentlemen who pur-
posed taking up the study of Bryology, in naming their specimens ; and he
hoped that during the coming excursion season many additions would be made
not only to the collection of Mosses which was gathered together by the club,
but also to that portion of the Flora of Middlesex now in preparation.

The President announced the Annual Soiree at University College, by the
kind permission of the Council, on Friday, March 11th.

K. T. Lewis.

ANNUAL SOIREE.

At University College, March 11th, 1870.

By the kind permission of the Council, the Club has again held its Annual
Soiree at University College, and in no respect was this last inferior to any of its
predecessors. The increased number of members since last year compelled the
Committee, rather against their will, to reduce the number of tickets allotted
to each member, below the allowance of previous years, but there was no other
alternative, except in overcrowded rooms. Notwithstanding this reduction, the
company was as large as the commodious suite of rooms could accommodate
with comfort to the visitors. The sources of attraction were so numerous and
varied that the only means by which we can hope to convey any idea of the
entertainment is to furnish as complete a list as we have been able to compile
of the principal objects exhibited. The Soiree Committee deserve the best
thanks of the Club for the success they achieved, and the exhibitors, for sup-
porting them in such hearty and efficient manner.

The following objects were exhibited by members and their friends, in the
Library and Museum : —

Allbon, W., Weevil, C (meatus tamarasii.

,, Eggs of Parasite of Mallee Bird.

Andrew, A. R., Tongue of Cricket.

,, Under Cuticle of Ivy Leaf, showing hairs.

, , Ivy Leaf, showing structure of veins.

Barratt, T. J., Section of Human Tongue, injected.

Bentley, C. S., Kidney of Cat.
Bevington,W. A., (No return.)

Blankley, F., Hairs of Fern, polarised

,, New Tank Microscope.

, , New universal Revolving Stage.

Bockett, J., Pollen of Hollyhock, by Ross' 4-inch, objective.

Brabham, T. B., Liver of Cat.

, , Muscle of Mouse .

,, Lung of Dog.

Brown, W, J., Sugar of Milk, polarised.

58

Burgess, N.,

j>

Cocks, W. G.,
Collings, T. P.,
Cooke, G. E.

Goniophlebium sepultum.
Hairs of Comfrey Plant.
,, Skin of Dog Fish.

,, Anguinaria dibiloba.

Carpenter, Stellate Hairs from Fern, Niphobolus hastatus.

Carruthers, W., Marshall's Large Double Microscope, as improved by Cul-

peper and Scarlet (date 1740).
(The conclave reflecting mirror was first employed in this

instrument.)
Anirnalculse from an infusion of Sage Leaves.
Podurse.
Fibro-cellular tissue of Aerides odoratum, an Orchid,

polarized.
Elytron of Diamond Beetle, Prapodes spectabilis.
Working Microscope of the late Eobert Brown, presented to
the exhibitor by the late Professor Quekett. This instru-
ment, one of the earliest Achromatic combinations, is by
Amici.
Large Microscope, by Tulley, improved by Powell, with

9-10ths objective (Tulley).
Fructification of Fern, Adiantum pubescens.
Volvox globator.
Podura Scale, with Crouch's one-eighth Immersion Lens,

by 800.
Portion of Mucous Membrane of human subject, injected.
, , Section of Brain, injected.

Eldridge, J. R., Stamen of Common Mallow.

, , Feather of English Kingfisher.

, , Feather of Humming Bird.

Circulation in Frog's Foot.
Winged case of Diamond Beetle.
,, Wing of Morplio Adonis.

Furlonge, W. H„ Pencil tail, Polyxenus lagurus.

»»

COTTAM, A.,

Crook,
Crouch,

Durham, A.,

Emery, J. J.,
Evans, E.,

Fitch, F.,
Fox, C. J.,

Fricker, C. J.,
Fryer, G. H.,

Gay, F. W.,

GOLDING, W. H.,

55

55

Gray, W. J. Dr.,
Groser, W. H.,

55

Groves, J. W.,
Hailes, H. F.,
Hainworth, W.,

Spider's Web, with insects.

Crystals of Copper and Magnesia, polarised — polarising ap-
paratus rotating by clockwork.
Pollen of Mallow.
Floscularia ornata.
Hydra viridis.

Spine of Turbot, Rhombus maximus, polarised.
Stings of Hornet.
Melicerta ringens.
Elytron of Chinese Beetle.
The Chigoe, Pulex penetrans.
Seed vessels of Fern (Todea).
Fruit of Antirrhinum Orontium.
Chlorate of Potash, polarised.
New Foraminifera.
Volvox globator.
Hydra viridis in gemmation.

59

Hancock, J. C,
Hislop, W.

HOPKINSON, J.,

Jackson, B. D.,
Jaques, E.,
Johnson, J. A.,
Kiddle, E.,

Kilsby, T. W.,
Lowne, B. T.
McIntire, S. J.,

Martinelli, A.,
Matthews, Dr.,

Milledge, A.,

MUNDIE, G.,
OXLEY, F.

Perry, P. T,,
Quick, W.,

}>
Babbits, W. T.,
Badermacher,J.

Reeves, W. W.,

5 J

5i
3J

Rogers, John,
Rogers, Joseph,
Rogers, Thos.,
Russell, J.,
i)

Russell, T. D.,

Slade, J.,
Smith, Alpheus,

>j

5>

Mandibles of Spider.
Crinoline of Lady's bonnet.
Crystals of Bichromate of Potash.
Crystals of Bichromate of Ammonia.
Crystals of Spiral Copper.
Section of Human Brain.
Vorticella nebulifera on Vallisneria.
Zygnema stellina, conjugated filaments.
Fructification of Hare's Foot Fern.
Young Oysters.
The Ruby Wasp.

Silver Spot Moth, and Eggs of the same.
Antennae of Gnat, in situ.
Wings of Cricket, with chirping apparatus.
External Skeletons of Insects.

Dichroic effects in scales of Urania leilus, a Brazilian Moth.
Pencil tails, Polyxemis lagurus, one of the Myriapoda.
Eggs of Lepidoptera.
Various Flowers.
Calliper Eyepiece.
Elytra of Beetles.
Scales of Farinosa (Beetle) France.
Medusa Polype.
Cyclops and Daphnia.
Section of the Toe of a White Mouse,
Lips of Blow-fly, and transverse section.
Gizzard of Cricket.

Foraminifera from the Mediterranean Sea.
J, Stellate hairs from Eleagnus leaf.
Pith of a Fern.
Microscope of eighteenth century, and revolving disc of

objects.
Young Brittle star-fishes Opliiocoma rosula.

Ditto Opliiocoma neglecta.

Young of Star Fish Comatida rosacea.

Ditto Solaster papposa.

Ditto Asterina gibbosa.

Ditto Uraster rubens.

Maple sugar, crystallized.
Section of Spine of Echinus.

Eye of Beetle, showing optical image in the lenses.
Asparagin polarised.

Circulation in Valisneria, by \ inch objective.
Daphnia pulex, by 2 inch objective.
Skin of Synapta from Channel Islands, anchor spicules and

plates in situ.
Circulation of Blood in a Frog's Foot.
Pollen of Hollyhock.
Peristome of Funaria Injgrometrica.
Section of Sugar Cane.

60

Smith, Jas., Disk mountings of wings of Lepidoptera.

, , Disk mountings of Eyes of Insects.

Suffolk, W. T , Splinter of deal, 4-10tks objective.

Wheeler, E , Insects from Ceylon, Tingis pyri.

, , Larva of Ant Lion.

,, Various Diatomacese.

White, T. C, Circulation in Young Trout.

,, Pencil tails, Polyxenus lagurus.

Wight, J. F., Spider in Amber.

Wright, E. Egg of parasite of Mallee Bird.

Mr. J. B. Jordan also exhibited his apparatus for cutting thin sections of
Rocks and other hard substances, with specimens of rock sections prepared
therewith.

Microscopes and Microscopical Apparatus were shown by the following
Opticians :— Mr, J. Bailey, Fenchurch- street ; Mr. C. Baker, 244, High Holborn ;
Messrs. R. and J. Beck, 31, Cornhill; Mr. C. Collins, 77, Great Titchfield- street ;
Mr. W. Crouch, 51, London Wall; Messrs. Home and Thornthwaite, Newgate-
street ; Mr. How, 2, Foster-lane, Cheapside ; Mr. W. Moginie, 35, Queen-square ;
Messrs. Murray and Heath, 69, Jermyn-street; Messrs. Powell and Lealand,
Euston-road ; Mr. T. Ross, 53, Wigmore-street j Mr. J. H. Steward, 406, Strand ;
Mr. J. Swift, 128, City-road.

Amongst the numerous other interesting objects, were : —

A series of splendid Photographs of Indian Scenery and Architecture, taken
by authority of the Indian Government, and kindly lent for the occasion by Dr.
J. Forbes Watson, of the Indian Museum.

Photographs of interest were also exhibited by Messrs. A. Durham, Frank M.
Good, and A. L. Henderson.

Lithographic Portraits of Eminent Naturalists by Mr. T. Crook.

Fac-similes of Egyptian Jewellery, from Egyptian Tombs, reputed to date
about 1860, B.C., exhibited by Mr. E. Kiddle.

British Natural History Collections, shown by Mr. T. D Russell.

Stereoscopic Views, with coloured illumination, by Mr. W. G. Cocks.

Stereoscopes and Stereoscopic Views, by Messrs. Murray and Heath.

Cases of Stuffed Birds, &c, by Mr. W. E. Dawes, jun.

A very large Collection of Microscopical Objects, by Mr. Edmund Wheeler.

Autotype Photographs, exhibited by the Autotype Company.

In the Shield Room, the Flaxman Drawings were exhibited, by permission of
the Council of University College.

Elee'.rical experiments with Induction Coils, Geissler Tubes, Gassiott's Cas-
cades, &c, by Mr. Apps.

The whole process of Micro -Photography by means of the Magnesium Lamp,
by Messrs. Solomon.

Dr. Maddox's Micro-Photographs, Alpine Scenery, Statuary, &c, were exhi-
bited by the Oxy-hydrogen light, throughout the evening, by Mr. How.

61

Microscopic Moulds.

i

By M. C. Cooke.
(Read March 25th, 1870. — Continued from page 53.)

One other mould from this order, and I must pass on to the
next. It is less common, but perhaps even more beautiful. Some-
times a decaying stem of Burdock, or similar plant, will be found
lying upon the ground in a damp situation, covered for two or three
inches of its length with a mould of snowy whiteness.

' ' Take it up tenderly,
Touch it with care."

It is so delicate that the slightest breath or shake is sufficient to
disperse the spores. Mycologists call it Botryosporium pulchrum, and
it deserves it. This is one of two British species, neither of which,
in my experience, is common. The threads are sometimes simple
and sometimes branched, very long for the size of the mould, and
flexuous or curved on account of their length. The lower portion
of the threads is naked for perhaps a quarter of their length. Above
this space short ramuli, or sporophores, are set on at regular
distances throughout the rest of the thread. Each of these sporo-
phores is narrowed at its point of junction with the stem ; at the
other extremity it is surmounted by four little spicules, and each
spicule supports a globose head of spores, so that four heads of
spores terminate each sporophore, and these together form a com-
pound head. The excellent figure in Corda's " Prachtflora" would
give a better idea of this mould than any description that I can
furnish.

From these examples it will be evident that much of the generic
character of the Mucedines depends on the mode of grouping and
attachment of the spores, hence it is of primary importance that
all specimens collected or mounted should have the spores in situ.
Whatever hints I may be able to offer towards securing this object
will be given at the close of this paper.

Journ. Q. M. C. No. 11. F

62 M. C. COOKE ON MICROSCOPIC MOULDS.

We pass now from the true moulds, which are usually white or
coloured, as seen in patches by the naked eye, to those which are
always found in more or less black patches, and hence have come
to be called " Black Moulds." These are not generally so delicate,
the threads are more rigid, and the spores are often more firmly
attached. They are found on herbaceous stems, bark, rotten wood,
and in fact in a great variety of localities. One of the largest
genera, that of Helminthosporium, and one of its commonest and
finest species, will furnish our first illustration.

Wherever holly bushes are at all plentiful, twigs and branches
cut down to stop gaps in the hedges, or that have lain on the
ground during winter will usually be freely covered with sooty
patches, variable in form and size, but looking just like patches of
soot, from the size of a large pin's head to some inches in length.
A portion of one of these patches will not make such a neat object
or such an attractive one as the majority of true moulds, or even
many of the Black Moulds, but it is always advisable to commence
an examination with a two-inch or one-inch power.

This Holly Mould will be observed to consist of erect simple
threads, bearing spores as long as themselves. The threads are
nearly opaque, of a dark brown, paler above and more translucent,
jointed and erect. But the spores are the most prominent feature.
Often longer than the threads themselves, and at first borne on
their apices, they are of a beautiful clear brown, nearly cylindrical,
a little attenuated towards each end, or sometimes club-shaped.
Throughout their whole length these spores are divided by
numerous septa into a number of cells, the largest in any
species of the genus with which I am acquainted. The name of
this fungus is Helminthosporium Smithii. (PL vii.) It is dedicated
to the immortal Smiths, so that the name of Smith may not be
forgotten. Had it been called magna or gigaspora it would doubt-
less have been far more appropriate, but such vulgar notions of
propriety do not always hover around naturalists when they name
a new species. It is a strange infatuation which besets some men
thus to immortalise the Smiths. I remember one botanist who
made a poor fellow's name do duty, as a specific name, for twenty
or thirty new species of plants. But it wasn't Smith.

Dead wood, rotten sticks, dead stems of herbaceous plants, and
dead grasses will furnish other species of the same genus. Most
of them so nearly alike in the appearance that they present to

M. C. COOKE ON MICROSCOPIC MOULDS.

63

the naked eye that the microscope must be resorted to for their
determination. In all these species the flocci are dark, erect, and
either simple or slightly branched, bearing here and there multisep-
tate spores. In such a species as Helminthosporium Tilice the
threads themselves seem to enlarge and develope into spores. In
some the spores are deeply coloured, in others they are nearly
colourless. Near two dozen distinct species have been recognised
in this country, and a few more workers would soon increase the
number.* It is sometimes objected that the species of fungi are im-
aginary. Let those which constitute the present genus be examined
carefully, and it will soon be discovered that the objection had its
foundation in ignorance. There must first of all be an apprecia-
tion of what constitutes a specific difference in fungi before it
can be maintained that there are no good species. It is admitted
that only a trifling difference in one or more organs, if compara-
tively permanent, is enough to constitute a good botanical species.
I am content to give up at once any one or more of the British
species of Helminthosporium, for instance, if it can be shown that
what are accepted as the specific distinctions are not permanent, in
the sense that permanence is accepted amongst flowering plants.
Indeed I incline to the opinion that variability within the limits
of a species is less than in the higher plants. The more ex-
perience one acquires the more firm becomes the conviction that
the general principles of classification in fungi are sound. Of
course this does not affect, and is not affected by the autonomy
of species. The evidence that a certain form is only a stylosporous
condition of an ascigerous species, does not prove that the stylo-
sporous condition is not of itself permanent in its stylosporous
character. It is a favourite theme with some who know little,
and care less, about fungi, to indicate the proven instances of
dimorphism, and jump at once to the conclusion that the study
is altogether a chaos, and that there are very few, if any, good
species at all. Because what has been known as Tubercularia
vulgaris is now proved to be a conidiiferous condition of Nectria
cinnabarina, that does not prove that Tubercularia vulgaris is in
itself so variable that no reliance can be placed on other species
of the same genus, or that the conidia were not sufficiently per-

* Anew species was figured and described in the " Gardeners' Chronicle"
of March 19th, under the name of Helminthosporium echinulatum, which is re-
markable for its echinulate spores, all previously known species having the
epispore smooth.

F 2

64 M. C. COOKE ON MICROSCOPIC MOULDS.

manent in themselves to warrant the prior recognition of Tubercu-
laria as a good species until its autonomy was placed beyond a
doubt. It would have been a very different thing indeed if Tuber-
cularia vulgaris could have been shown to have passed into Tuber-
cidaria granulata, or any other species of the same genus. Such
an event would have affected the soundness of specific distinctions,
which dimorphism does not.

Passing from Helminthosporium, we may sometimes meet with
effused velvety black patches, on decorticated oak, which, although
similar to the naked eye ; are very different in character when
seen under the microscope. This is Triposporium elegans (Plate
viii.). The flocci are also dark coloured, erect, and branched, but
the fruit is very different ; it consists of tri-radiate articu-
lated spores. Recently, Mr. Broome has found these spores
with swollen and rounded tips ; a circumstance from which it
would at present be premature to draw conclusions. Noth-
ing of the kind is known in Helminthosporium. The Tripos-
porium is, then, something like a Helminthosporium with compound
spores. Other species are found in other parts of the world, and
this seems to strengthen the genus as perfectly distinct from Helmin-
thosporium. It will be time enough to doubt its generic value
when some one has demonstrated the tendency to a similar form of
fruit in any good species of Helminthosporium.

Amongst the -numerous and interesting fungi which are found
growing on dead stems of nettles, there is one which may be al-
luded to as exhibiting a variation in the structure of the stem,
which is found also in some other genera of the Black Moulds
(Dematiei). I allude to Arthrobotryum atrum. The stem is in
this instance a complex one, composed of numerous threads, or
flocci, which are collected together and combined into a common
stem, which seem at first to support a globose head of spores,
but upon closer examination each of these spores will be seen to
have its own proper stem or thread, and by their agglomeration
the spores assume the form of a more or less globose head. In
the present instance the threads are swollen above, just at the
point of junction with the spores, and the spores themselves are
nearly elliptic, divided by transverse septa, with the central por-
tion brown, and the terminal joints colourless. A similar species
with smaller spores is found on willows, and what I think is an un-
de scribed species, on decaying grass and straw. Here, again, in

M. C. COOKE ON MICROSCOPIC MOULDS. 65

the structure of the stem, we have a decided generic difference
between these species of Artlirobotryum, and those of the other
genera alluded to.

The dead stems of such umbelliferous plants as the common Hog-
weed, Angelica, &c, also nourish Black Moulds, and one of these
may be taken as the type of another genus. I allude to Den-
dry phium fumosum, figured by Corda under the name of Dactylium
fumosum. The branched threads in this species (Plate v.) are sur-
mounted by large and beautiful elongated fusiform brown spores,
which are transversely divided by numerous septa. One peculiarity
in their mode of growth is that the spores are produced in chains ;
that is, one spore supports another at its apex. This concatenate
condition of the spores is not always readily made out, because
the attachment is so slight that unless great care be exercised, only
single spores will be found attached to the threads. In some
other species the attachment is more permanent.

By comparing together the examples I have given of the
Dematiei, the general features of the order will be readily appre-
hended. The threads are free, or sometimes collected together so
as to form a compound stem. They are also more or less fur-
nished with an outer membrane, which may often be seen peel-
ing off in the flocci of Helminthosporium, and have a burnt or
charred apj>earance, never white or of pure tints, as in the
Miicedines, and the spores have frequently the same carbonized or
brown tint. The distinctions between these orders are, I think,
manifest in the characters I have given.

These are the two largest orders in the family to which they
belong, but there are four others, each containing a few genera, to
which I must allude. A few years since our worthy secretary, at
that time, called my attention to some cat's clung which was found
in one of his cellars. It was covered with a curious-looking
mouldy substance, but there were no heads, and the thick snow-
white coralline threads had a peculiar powdery appearance. When
examined under the microscope, these threads, or branching stems,
were found to be composed of a mass of delicate hyaline threads,
bearing a profusion of powdery minute spores at the surface. It
was Isaria felina, found for the first time in Britain. A similar
structure prevails through the order to which this species belongs.
The common stem is compound, and the powdery spores are borne
on the surface, giving the fungus a peculiar pulverulent appear-

66 M. C. COOKE ON MICROSCOPIC MOULDS.

ance. It is not uncommon to find dead pupae of insects and dead
spiders bearing similar compact moulds ; but these are now
admitted to be conidiiferous states of Entomogenous Sphaerias,
belonging to tbe genus Torrubia. Probably several others have a
similar development, although the condition is at present unknown.

That very common red fungus which is found at this time of the
year on almost every rotten twig, Tubercularia vulgaris, may serve
as a well-known example of the Stilbacei. It is, doubtless, entirely
a spurious genus, that is, the species which compose it are but
conditions of other forms, yet it is common, and fairly illustrates
the order to which it has been assigned, whereas species of the
genus Stilbum are not always to be met with, especially when they
are wanted. In Tubercularia there is a somewhat globose head
and a short stem, sometimes so short as scarcely to be recognised.
This stem, and also the head, is entirely composed of slender com-
pacted threads, and the surface of the head is covered with very
minute gelatinous spores, which form an investing stratum. As
this species is so common, I would advise everyone to make the
examination for themselves, and thus they will understand the
structure infinitely better than from mere description. It repre-
sents a compact complex mould, and in general appearance has no
resemblance whatever either to the true moulds, or the black
moulds, though more closely related to Isaria. From the stroma
of this Tubercularia its perfect form {Nectria cinnabarina) will often
be found emerging.

Another very common fungus, found on nettle stems, which
again is a condition of a higher form (Peziza) belongs to this
order. It appears in small orange-coloured spots on the stem,
swollen and gelatinous when moist, but flattened into a little waxy
spot when dry. In this instance the receptacle is like a disc, and
in the perfect condition it becomes a shallow cup. It is much more
gelatinous and tremelloid than the Tubercularia, but equally com-
mon. From one of its prominent features it is named Fusarium
tremelloides, and not long since it was included amongst the
Tremellas. Let me advise everyone to take the opportunity of a
stroll or an excursion during this month or the next, and examine
the nettle stems which have stood through the winter, especially in
a damp situation. Near the bottom of the stem, often running
half-way up, they will discover myriads of little orange spots the
size of a pin's head. If a piece of this stem be brought away, and

M. C. COOKE ON MICROSCOriC MOULDS. 67

the end placed in water, if not already moist, then as soon as the
little points appear convex and gelatinous, remove one on the point
of a penknife, flatten it upon a slide by pressure on the cover,
and examine the structure with a quarter inch, adding a drop of
water at the edge of the cover when the object is well in focus,
then look and learn. Of course those whose sole ambition is a
pretty object, and nothing more, need not trouble themselves, as
they are likely to be disappointed.

I will not detain you over the remaining two orders, as they are
of little importance. In the Sepedoniei the flocci are so much sup-
pressed that the spores seem to be the principal feature. Perhaps
the only true genus represented in Britain is Fusisporium. It is
very doubtful whether Sepedonium, Epochnium, and Psilonia are
not soon doomed to oblivion. The spores in Fusisporium are long,
spindle-shaped, curved and septate, forming a gelatinous mass.

In the last order (Trichodermacei) the spores are invested by
the flocci, forming a sort of spurious peridium. The most common
and typical species is Triclwderma viride, which forms at first
whitish, then greenish, mouldy tufts on dead wood and fallen
branches. This is the only British species of Triclwderma, and
the Messrs. Tulasne have shown it to be a condition of Hypocrea
rufa.

From these eursory observations you will gather that, considered
in the light of microscopical objects, two orders of the Hyphomy-
cetes only can be strongly commended to your notice. Of course
those who are desirous of extending their knowledge of the lower
forms of vegetable life will not rest content with such only as may
be attractive ; but I am afraid that there exists too little interest in
the subject for me to hope that many are prepared to pursue the
study of Fungi, except under the most favourable conditions and
with the most attractive forms. It will prove a source of satis-
faction if I am disappointed.

The collection of moulds requires to be conducted on similar
principles to the collection of other objects, and no special instruc-
tions are needed, except on one point. Moulds are exceedingly
delicate, and cannot be bottled or placed loosely in a vasculum ;
indeed, if each specimen or species is to be of value it must be
isolated from all others in such a manner that the spores of one
cannot by any accident become intermixed with the flocci of an-
other species. To avoid this I find it advisable to employ small

68 M. C. COOKE ON MICROSCOPIC MOULDS.

boxes, chip boxes will serve, with corked bottoms, or small insect
collecting boxes, and, as soon as a specimen is found, carefully
to cut away all extraneous portions of the leaf or stem of the
plant on which it is growing, thrust a pin through it, and
fasten it in the cork of the box as one would a butterfly or moth.
* If the specimen is a very delicate one the box must be carried
home in the hand, if the mould is to be secured in prime con-
dition. The greatest care must be taken in trimming up the
matrix of the mould to employ a sharp knife and cause as little
jar or vibration as possible to be communicated to the mould, or the
sj)ores will be dislodged.

Supposing that the mould is safely conveyed home, the next
subject for consideration is how to examine or mount it. The true
moulds or Mucedines are the most delicate, and require the great-
est care both in collection and preservation ; if moderate success
be achieved with these all the rest is easy. On no account must
moulds be placed in fluid of any kind for examination, or all the
spores are instantly removed, and nothing is left but the bare flocci ;
this may be necessary for the examination of the threads them-
selves, but it is fatal to the mould.

Cells of any kind, tin cells, glass cells, vulcanite cells, or any
other cells, fixed upon glass slips are the best for the purpose. A
small portion of the mould, carefully removed with a sharp pair of
scissors, taking care not to touch the mould, but to cut the leaf or
stem, and remove the fragment with its portion of mould attached,
and at once place it in the cell, fix it or not as taste may dictate,
and put on the cover, fastening it in position with a spring clip.
I should not myself fasten down the thin cover for twenty-four
hours, in order that what moisture there might be in the mould
or its matrix might find its way out. If closed at once the glass
is liable to become dull, and remain so for some time, on account of
the evaporation of the enclosed moisture. Such a slide will, if
neatly manipulated, prove a most attractive object for a low power,
say one or two inches, especially if well illuminated.

To examine a mould satisfactorilv it must be mounted free from
compression, and it must be seen as an opaque object. Further, it
should be seen with the amplification of a quarter-inch objective
to make out the details. Here then is the great difficulty. To
examine an opaque object under plenty of light with a quarter-
inch, and such a quarter-inch of good penetration. Some will

M. C. COOKE ON MICROSCOPIC MOULDS. 69

advocate perhaps a Lieberkuhn, or similar mode ; my own impres-
sion certainly is that we are deficient in the means of viewing
opaque objects satisfactorily with a quarter-inch. I must confess
that I can do no good with a Lieberkuhn on a quarter-inch ; per-
haps I may be a bungler. One great objection which I have, for
my purposes, to modern and good English high powers, lies in the
quantity of metal which the makers give us. A small nozzle is
required, the smallest possible, so that with side reflectors and
condensers we might get light, whereas usually there is greater
breadth in the quarter-inch than in the inch, hence we get more
light with the German powers, because the "nozzle" is smaller. (If
I may use such an undignified term as " nozzle,") I would suggest
to some spirited maker the manufacture of a quarter-inch with the
smallest possible diameter at its extremity, so that all those who,
like myself, believe in objects seen as they are, without having the
light thrown through them, may gratify their depraved (?) tastes.

And now, as to the examination of moulds in the best way we
can, under existing circumstances with high powers. A smaller
portion, consisting of but two or three flocci carefully removed, and
placed on a glass slip, covered and fastened clown forthwith without
the slightest movement of the glass after it has touched the object,
will sometimes give a moderately good slide for the quarter-inch.
The heads of spores will be broken or distorted, and other allow-
ances will have to be made ; but this is the only way in which I
have been able to make out the structure, for instance, of the
sporophores of such a mould as Botryosporium.

The " Black Moulds " and some other of the Hyphomycetes are
far less delicate than the Mucedines, and many of these, as
Helmintlwsporium and Macrosporium, might be mounted in balsam,
although I think that very few indeed of the Microscopic Fungi are
not much better in diluted glycerine — the cover being fastened down
with gum dammar dissolved in benzole — than when mounted in
that medium, in Deane's gelatine, or in balsam. Some persons
have a mania for balsam, but it is clear to me that the miserable
collapsed spores and threads of specimens mounted in balsam,
when I had less experience, are only caricatures of the things
themselves in a state of nature, or even when preserved in diluted
glycerine.

Already I find that my remarks must close without reference to
a very important subject, which it was my intention to have in-

70 M. C. COOKE ON MICROSCOPIC MOULDS.

eluded— namely, the dimorphism of Fungi— especially as asso-
ciated with moulds. It is, however, of so extended a nature, and
my observations would necessarily reach to some length, so that I
am compelled to postpone until another occasion the consideration
of these phenomena. As examples I might mention Dactylium
dendroides (PI. iv.) amongst the Mucedines, and Cladosporium
herbarium as one of the Black Moulds.

PI. iv, — Dactylium dendroides.

PI. v. — Dendryphium fumosum — after Corda.

PI. vi. — Polyactis fasciculata.

PI. vii. — Helminthosporium Srnithii.

PI. viii. — Triposporium elegans— after Corda.

GATHERINGS AT EXCURSIONS.

The following is a list of the gatherings 1 made at the Excursion to
Wandsworth Common on 2nd April:— Stephanoceros, very abundant and
large; TSJelicerta ring ens also; llosadaria, not many, and apparently young;
Limnias ceratopliylU, Vaginicola crystallina (green, double-bodied), plentiful;
Tubicolaria a few ;, Vorticella chloro stigma, plentiful ; Stentor, very large a
few ; VoUox globator, abundant, disintegrated ; Actinoplirys oeulata, mod%
rately abundant ; Euglena viridis ; Hydra viridis, very bright green ; i*
curious Amoebiform Protozoan, continually changing, like frosted silver,
under a spot lens, the granules constantly moving like the swarming of
Closterium ; Biffiugia, Rotifers, Pandorina morwm, Staurastrum, Cosmarium,
and Docidium, the last three conjugating ; with a goodly number of Stato-
blasts.—T. C. White.

Carsh Alton, 14th May. — The following were collected : — Melosvra num-
muloides, Sjrirogyra quirina, Tardigrada, Navicida cuspidata, Navicula
didyma, Paramecium aurelia, Fragillaria capueina, Gomplwiiema acuminata,
Meridion circulare (seven or eight frustules), Pinnularia oMonga, Euglena
viridis, Pandorina morum, Epitliemia turgida, Cypris tristriata, Rhabdo-
nema arcuata, Choetonotus larus, Noteus auadricornis, Rotifer vulgaris
Canthocampus minutus, Metopidia triptera, Tabellaria floecidosa, Surirella
bifrons, Pinnxdaria obloyiga, Conferva flocculosa (with zoospores, and in con-
jugation), Diatoma vulgare, Syncdra splendens, Synedra capitata, Nitzschia
lanceolata, Nitzschia longissima, Pleurosigma Spenceri, Vorticella nebulifera,
TJlothrix mucosa, Pinnularia radiosa. — J. M. Ramsbotham, M.D.

71

On Ciliary Action in Eotifera.

By N. E. Green.

{Read April 22nd, 1870.)

The subject of ciliary action in Rotifer a cannot but be interest-
ing. The movements of these wonderful hairs — which seem to
perform not only the duties of hands and feet, but to supply the
place of all the five senses combined — are the first to attract atten-
tion when looking at this phase of animalcule life as exhibited in
the microscope ; and when an earnest examination of the nature of
these movements is commenced, the study acquires a fascination
peculiarly its own.

In order somewhat to systematise the treatment of the subject,
we propose to divide the general action of cilia into groups,
speaking first of those hairs which occupy a forward position, and
are thus placed nearest the source of supply. These, for want of
a better name, we will call " informers," their apparent duty being
to ascertain the state of the surrounding water, and give timely
notice of the approach of food. We will, then, offer a few obser-
vations on the construction and movements of those wonderful
crests of undulating cilia, usually called the wheels, from whose
action a continuous supply of nutriment is derived, and brought
within reach even of those occupying a fixed position. From these
we will pass to a consideration of those cilia which examine, and
receive or reject, the various particles drawn in by the action of the
wheels, and from this important duty deserve well the title of
" inspectors ;" and conclude the paper with a few remarks on the
cilia which line the gullet, and whose occupation is evidently to
thrust forward the food into contact with the gizzard, or, in the
absence of this organ, to make it up in pellets suited for home
consumption.

The cilia which we have called the informers, and whose duty
appears to be to convey information of the state of the surrounding
water, are few and short in the common rotifer, and long and

72 N. E. GREEN ON CILIARY ACTION IN ROTIFERA.

abundant in the floscule, but each animalcule of the wheel-bearing
class possesses them more or less. In the common rotifer they
terminate the process which extends from the head when the
wheels are withdrawn, and may be seen in frequent vibratory
action, as though testing the condition of the water, while the body
of the creature is moved here and there in search of food. When
their report is encouraging, out come those wonderful appendages
and work as usual ; but should the result not equal the expecta-
tion, they are withdrawn, and the informers again employed. We
have observed this action particularly in those individuals which
had been kept for some time in a limited supply of water.

In Vorticella, Brachionus, Philodina, and especially in Melicerta
Floscularia, and Stephanoceros these hairs may be observed, and in
each case their duty seems to be somewhat the same. Those ac-
customed to watch the movements of Vorticella may have observed
the manner in which that beautiful anterior fringe of cilia, which
assists in the formation of the vortex, is sometimes thrown
forward, straight and motionless, though but for a moment ; but if
its answer is not satisfactory, another jerk is given, and a fresh
examination made before the rotatory movement is set up. Again,
in Melicerta, how many weary moments have we spent in watching
those tufts of short cilia, which just peep over the edge of the case
when the animal is retracted, and are evidently designed to convey
information of any change in the surrounding medium — this may
be tested by allowing a few drops of fresh water to pass over the
end of the case, for soon the influence is felt, and the creature
comes slowly out to realise the benefit of the change. But with-
out some explanation of this kind, it seems difficult to assign a
duty to those infinitely delicate threads which radiate from the
head of the floscule — these would be little better than unnecessary
excrescences if some useful work is not performed by them.

With regard to the wheels, we will first make a few observa-
tions on the direction of the movements of cilia, by which the illu-
sion of rotation is produced, and then speak of the duplicate
character of the organ itself; and if in these remarks we simply
repeat the statements of others, even this repetition is not destitute
of value, for on a subject of such intricacy, every independent testi-
mony is acceptable. We have watched both earnestly and long to
discover the nature of these rotatory illusions, and not until the
anhnalculae had been kept in the same limited supply of water, and

N. E. GREEN ON CILIARY ACTION IN ROTIFERA. 73

their action reduced by this means to a fitful or languid move -
ment, could we arrive at a satisfactory conclusion ; but at last an
opportunity was afforded in the case of a very fine Stentor, who
found trade so bad that he had shut up shop, and seemed inclined
to retire from business altogether, but was induced to recommence
operations by the stimulant of a little fresh water. The move-
ments of the cilia were at first so slow and deliberate that the
action of each hair could be easily followed. Before the addition
of the water the fringe extended upright and motionless from the
head, but as the reviving draught passed over it, first one hair and
then another bent slowly towards the centre of the disc, returning
to the upright position at a still more leisurely pace ; then two or
three would follow each other gently in the same movements — soon
a whole side went down, but in a progressive wave, resembling
the action of wind on a field of corn ; and, in less time than is
occupied by the description, this movement became circular, in-
cluding the whole of the fringe, wave after wave passing round it
in the most beautiful and regular manner, till at last the waves
followed each other in such rapid succession that the eye failed to
follow them individually, and the illusion of the rotatory movement
was complete.

On one occasion, when watching a Vorticella, the wave was ob-
served to rise and fall like the sullen beat of surf on the sea shore,
and as a wave, when falling at a slight angle with the coast, will
sometimes seem to dart along the shore a mile in a minute, so
when the movement of the cilia has been most deliberate the wave
has appeared to pass round the fringe like a flash. We might
multiply instances, but the conclusion to which we come in all, is,
that each cilium moves in a very elongated oval, that the greatest
energy of its action is inwards, that the movement is progressive,
one hair following very rapidly upon another, producing the ap-
pearance of a wave, and that these waves following each other
round the circle of cilia effect the illusion of rotation ; this illusion
being most complete where each cilium moves most slowly, viz., on
the outer edge.

This peculiarity of illusion is most evident in the common
Kotifer, Philodina, Brachionus, and Melicerta, for in these animal-
cule the individual cilia are longer, and have a whip -like character,
the lash recurving in its stroke over the ridge on which the cilia
are placed. But in the Vorticella the wave-like movement is so

74 N. E. GREEN ON CILIARY ACTION IN ROTIFERA.

rapid in the anterior row, that the fringe itself disappears, and
what is usually seen at the margin of the cup is simply a vibratory
movement of the stouter hairs of a second or posterior series.

We cannot leave this subject without referring to a charming
scintillating movement, observed in Conochilus volvox, when the
action is ceasing ; it results from an energetic stretching out and
momentary rest of each cilium, when at that part of its action
furthest from the centre. The effect of this momentary rest is to
produce a radiating and progressive scintillation, the beauty of
which is beyond the power of description, and must be seen in
order to be appreciated.

During these examinations we frequently observed a duplicate
arrangement of the cilia forming the wheels ; this first attracted
notice in the vorticella, for when their movements became languid
an inner and an outer row were clearly seen; the inner long and
close set, extending from the bell like a silken fringe ; the outer
fewer in number, stouter in form, and radiating from the centre.
It was also evident that the two rows were not always in action at
the same time, for in some instances a movement in the inner circle
preceded that of the outer, and in several instances the inner was
observed in slow action, while the outer remained stationary. We
have already remarked that the peculiar appearance at the margin
of the cup seems to be due to a vibratory movement of this outer
series, and a careful examination will make this evident, for the
extremes of action are marked by a ghost-like cilium, and between
these there may be observed a faint fan-like cloud, produced by
the passing and re-passing of the cilium over the intervening
space. This movement is evidently very different from that of the
wheels. Truly wonderful is the power possessed by this atom,
feed it with a little indigo, and observe the vortex formed by its
action ; the particles are drawn in on all sides as by a maelstrom,
while a long stream of rejected matter is thrown off like smoke
from a steam tug. May not part of this amazing energy be ac-
counted for by the united action of the two fringes of cilia, the
anterior drawing in, while the posterior drives off in all directions?

But to proceed. We have observed this double series or some
modification of it in Stentor, Brachionus, common Rotifer, Philo-
dina, Vaginicola, &c, and in a former paper mention was made of
a similar series in Melicerta. In the common Rotifer, Philodina,
and Brachionus, the second series is placed under a fold of the

N. E. GREEN ON CILIARY ACTION IN ROTIFERA. 75

crest from which the anterior fringe proceeds, and is chiefly instru-
mental in taking up particles drawn in by the front series, and
conveying them to the mouth, while in Melicerta the second series
is placed on the back of the lobes, and the waving movement, in-
stead of being in one direction only, as in the outer fringe, is in
two directions, both leading to the gullet.

In all these instances we have been speaking of a movement
which, however bewildering, is still distinctly visible ; but there is
one member of this family in which the means by which the food
is induced to come in, is invisible, at least to any but a most close
and patient observer ; we allude to the floscule. How often have
we been surprised to see a monad swimming in all the unconscious-
ness of animalcule life, in the neighbourhood of one of these crea-
tures, taken as it were with a temporary fit of insanity, and pre-
cipitate itself into the bell-like mouth, when a slight contraction of
the neck indicated that it was all over with the unhappy monad.
Surprised we have been indeed, and sorely puzzled to divine the
cause of these strange movements, or to make out the hidden
source of their power.

Slack, in his charming work, " Marvels of Pond Life," page 76,
refers to this power in these words : " Some internal ciliary action,
quite distinct from the hairs, and which has never been precisely
understood, caused gentle currents to flow towards the mouth in
the middle of the lobes," &c. ; and in Prichard's standard work,
page 667, Gosse is quoted as an authority : " That in Floscularia
rotation is accomplished not by the tufts of long setas, but by cilia
set, on the inner surface of the disc." This seems very definite,
but we read again, page 675, with the authority of the same name,
" That the setigerous lobes are not the true rotatory organ, yet
there is a rotatory organ, the particles of floating matter revolving
in a perpendicular oval within the mouth of the disc, hence I con-
clude that the rotatory cilia are set in the inner surface of the
disc."

We find from these quotations that both Slack and Gosse have
regarded the precise situation and nature of the rotatory organ of
the floscule as still open to investigation. Having been supplied by
our good friend, Mr. George Fryer, with a stock of these in-
teresting creatures from his tank, we set to work to unravel the
mystery ; but many means, and kinds of illumination were tried
without avail. There lay the beautiful floscule, apparently motion-

76 N. E. GREEN ON CILIARY ACTION IN ROTIFERA.

less, yet the mad gallop of the monads continued, some driving
backwards and forwards before the opening to the mouth, but
meeting on every side an almost impenetrable series of setae, were
at last compelled to enter ; here we have seen three or four at a
time awaiting their fate, when presently the ominous contraction of
the neck is given, a beak-like process advances from the centre, and
with unerring aim seizes on each in succession. Most provoking,
certainly, and not to know anything about it. So, to work again,
this time trying dark ground illumination with T ^, and by this
means much was learned of the quiverings, shudderings, or strikings
of the seta3 ; these movements were sometimes so continuous and
effective that both Mr. Fryer and the writer thought that the seat
of power lay in the shorter spurs of seta?, which extend far into
the bell-like opening ; but a more prolonged examination made it
evident that these movements were employed rather to keep the
passage clear, or to increase the current, than to form the current
itself, for this still continued when the seta? were at rest.

At last, having given them a few days to consider whether they
would yield their secret or no, we commenced operations one even-
ing about eight, on a specimen extended bell-upwards, and working
so slowly that some particles of indigo with which it had been
regaled on a previous occasion, were flowing slowly over the brim
into the cup, and coming out again at an equally steady rate. The
resolve was immediately made to trace the course of these particles,
being assured that wherever the hidden cilia might be, there the
movement of the indigo would be most accelerated or disturbed.
Many particles were watched in succession ; they passed unmoved
over the shorter seta?, where, on other occasions, we had seen them
driven about in wild confusion ; but on arriving at the contraction
of the neck, and just at that j3art where the interior bulges out into
a wider form, they were invariably agitated, some passing over it
with a jerk, while others were returned in their course, thus com-
pleting the perpendicular oval referred to by Gosse. Those particles
which had passed this rim were observed to cross leisurely over the
flattened surface which surrounds the mouth ; but in coming out
were again disturbed or jerked, some, indeed, were retained and
agitated in such a manner that an imaginative eye might readily
have seen the cilia by which their dance was produced ; but being
in a very matter-of-fact mood, we only felt assured that there they
were, if we could only see them. Still, after some hours of effort,

N. E. GREEN ON CILIARY ACTION IN ROTIFERA. 77

and trying every available power and kind of illumination, we were
about to give it up once more, when, wandering over the slide with-
out any definite intention, we came upon an unusually fine individual,
this time stretched longitudinally, and in steady work. The im-
mediate neighbourhood of the ridge was, of course, the part scruti-
nised, and again the dance of the indigo was observed, and every
now and then, the eye seemed to catch the usual flash-like action of
cilia. We had been working with an exquisitely corrected quarter-
inch by Dalmayer, and with the usual light transmitted through a
quarter-inch achromatic condenser. The former power was ex-
changed for a -jjr by Ross, and the condenser adjusted with great
care, when, on bringing this power into focus on the further side of
the chamber, and then raising it in the most delicate manner, so as
just to focus that which lay above the surface, our eyes were feasted
on the sight of a row of cilia in active operation. Yes, there they
were ! — one, two, three, we could almost count them round a por-
tion of the curve ; short, thick-set, directed towards the mouth,
and busily engaged producing the current, the cause of which had
baffled us so long. The hour was near twelve, and the eyes had
been more than once bathed with cold water to enable them to bear
the strain, so the gas was turned out, and we prepared to turn in,
well satisfied with the result of our four hours' search.

Since this time we have on several occasions verified the fore-
going statement, a careful examination of the same locality having
seldom failed to reveal these mysterious hairs. Still, we would de-
sire to caution any of our friends, who may wish to see for them-
selves, that there are peculiar difficulties in the way of success. It
is in vain to try on an individual fresh from a free supply of water ;
the action is too rapid, a slide must be kept for some days in order
to reduce the energy of movement. Then it must be remembered
that the cilia are placed just where it is most difficult to see them
(see Plate ix.), and the thickening of the integument or side of
the chamber makes it doubly difficult to separate so delicate an
object from the side itself. The only available situation, at least
in our experience, is that described, viz., the inner surface of the
further side.

But our programme would be incomplete without some reference
to that very useful body of cilia which we have termed inspectors,
whose duty is to examine the general mass of particles drawn in
by the action of the wheels, to select that which is suitable for

JOURN. Q. M. C. No. 11. g

78 N. E. GREEN ON CILIARY ACTION TN ROTIFERA.

food, and reject the remainder. It is truly wonderful what an
amount of work they get through, considering the mass of material
which is constantly thrown on their hands, or, we should rather
say, their fingers. In Melicerta there are two cushions, each armed
with a phalanx of active cilia, which guard the entrance to the
gullet ; and when the supply of nutriment is too abundant they
close over the opening, and thus save the gizzard from repletion.
But in Brachionus, Philodina, and the common Rotifer, the inspectors
may be seen as a distinct series of hairs, and their duty is unmis-
takeable.

When a particle has passed this ordeal it is allowed to enter the
gullet, where it is immediately taken up and hurried forward to
the gizzard by those cilia which line the passage, and whose action
is so constant as to raise the idea of running water.

In a Brachionus a very peculiar movement was observed in the
throat when the stock of food was getting short. The cilia seemed
to form themselves into a writhing, tongue-like process, the move-
ments of which resembled a flame. This was sometimes thrust
towards the gizzard, and again turning in its course, stretched for-
ward to the mouth, as though anticipating the needed supply.

It may also be observed that a movement of the cilia in the
gullet precedes the throwing out of the wheels ; and that in the
case of a poor Melicerta who had been evicted, this internal action
continued long after all exterior effort had been abandoned.

When the gizzard is wanting, a most important duty t seems to
be assigned to the last of these internal cilia, viz. — the making up
of. the food into pellets. In some species of vorticella this has
been distinctly seen, the movement reminding us of that which is
observed in the mold of the Melicerta. The food seems also to be
amalgamated with some secretion of the animal, for instead of
mingling with the matter in the interior, it retains its globular form.
These pellets are then passed forward by a general action of the
interior, and reduced in size by absorption till they approach the
exit, where they sometimes coalesce before they are discharged.
The cilia covering the bodies of such creatures as the Stentors, are
evidently of great value, as by their continued action they cause
these discharged matters to pass away, which otherwise might ac-
cumulate, to the great annoyance of the animal.

But we have not quite done with ciliary action yet, and
this last instance is, in our experience, unique. A rotifer re-

N. E. GREEN ON CILIARY ACTION IN ROTIFERA. 79

sembling the Pterodina of Pritchard, was once seen furnished with
a wheel-like movement at the end of its tail, so that its loco-
motion might be likened to that of a paddle-wheel steamer with an
auxiliary screw. By this apparatus at the end of the tail it at-
tached itself to the glass or weed, and the rotatory movement then
ceased, but recommenced some seconds before departing in search
of a better situation.

We have thus sketched the general characteristics of ciliary
action in Rotifera, commencing with those occupying the most for-
ward position, and concluding with a singular instance of their
presence in the rear. May we not, ere we close, consider for a
moment the infinite perfection displayed in their arrangement, and
the exquisite adaptation of the means to the end ?

When these and similar investigations are made in a spirit of
scientific research alone, how keen is the enjoyment, how pure the
delight ; but if, while contemplating the wonders of the creature,
the mind is raised in adoration to the Creator, then indeed is the
civp of pleasure full.

Could the secrets of but one road-side pool be told, oh ! what
an anthem would arise to the great Original ; and if our hearts
are in tune with nature, we shall ever be ready to join the chorus
in praise of nature's God.

Coming Excursions.

The Excursions of the Club for the coming quarter are for July
9th, Barnet for Totteridge, to meet at King's Cross Station ; July
23rd, Bromley for Keston, to meet at Ludgate Hill Station ;
August 6th, Thames Ditton, to meet at Waterloo Station, main
line ; August 20th, Grays, to meet at Fenchurch Street Station ;
September 3rd, East End for Finchley. to meet at King's Cross
Station; September 17th, Snaresbrook, to meet at Fenchurch
Street Station. In all cases by the earliest train after two o'clock.
The Excursion Committee hope that they will be encouraged by
the presence of a large number of members.

g2

80

On a New Method of Substage Illumination.
By Dr. J. Matthews.

(Bead 27th May, 1870.J

I must confess to a feeling of considerable difficulty in introducing
the subject of my paper of this evening to your notice. I had
been at work many months upon it, when it suddenly came to my
knowledge, about three weeks since, that I had fellow-workers in
the field, and that we had all arrived at results very nearly alike,
by similar means. Nay, more — that those means had been
hinted at or foreshadowed in the pages of Carpenter, Hogg, and
others, and even employed by Tollit and Davis. But my experi-
ments were then complete, so that I think I may fairly claim to be
at least one of the first who has employed these new agencies, and
applied them in a formal and convenient way to the microscope,
so as to facilitate their use and give precision to their results.
But previously to laying before you these results it may not be out
of place to notice briefly the present modes of substage illumina-
tion.

First is the plane or concave mirror — reflecting daylight or lamp-
light, and in so doing absorbing about half the incident rays, to
the great detriment of its use with the higher powers, besides
giving images from both front and back surface so that the direct
light of the lamp was often substituted — an excellent plan, easily
applicable to almost all cases.

Next is the prism, either rectangular or equilateral — bounded
by plane surfaces — first employed in the Newtonian telescope.
This was a great advance, as by it nearly all the rays are reflected,
and there was only one image given. Amici and Abraham curved
the two surfaces opposite to the reflecting face of the prism into a
lenticular shape, by which it became a condenser as well as a re-
flector ; a most valuable improvement, especially in that of Abraham
who made his achromatic. The " Diatom prism," of Mr. Reade,
is of the former kind. All these (except that of Mr. Abraham)
possess more or less of these faults ; that they do not reflect light

DR. MATTHEWS ON A NEW METHOD OF ILLUMINATION. 81

equally at all angles, and notably least at the most oblique
— a circumstance fatal in practice — and that they impart colour
to otherwise colourless objects, either by refraction or probably
some amount of polarization and perhaps diffraction.

" Nachet's " prism — in which light is taken from the plane mirror
(but not necessarily so), conveyed by two internal reflections to its
apex, which is surmounted by a plano-convex lens, and thus con-
verged on the object — is another form of great merit, for it con-
denses oblique rays and is so mounted as to throw them in any
azimuth by a revolving fitting. But, as its angle is unvarying, it
has not been attended by the advantages expected.

It was speedily found that in none of these methods is sufficient
light reflected in the use of the higher powers, so that it became
necessary to devise some means of concentrating more light upon
certain objects under certain requirements. Out of this necessity
grew a new, complicated, and expensive instrument, called a con-
denser. This certainly fulfilled its purpose well, too well in fact,
for in the blaze of light thus collected, nearly, if not quite, all de-
finition was lost. This speedily demanded and obtained a remedy,
though it was, as I shall presently endeavour to show, of the most
objectionable kind. And here arises an involuntary sigh of regret
that so much ingenuity of arrangement, such delicacy of construc-
tion as is displayed in the condensers of our best English micros-
cope makers, should be expended in such a wrong cause, in such
an erroneous direction, while, as is too often the case, the remedy
lay at our very feet, unnoticed and neglected !

Condensers are of two kinds, though similar in principle and
but slightly varying in construction.

Firstly. One or more lenses interposed between the mirror and
the object, not achromatic. Of this kind Mr. Reade's " Kettle
Drum " is a good illustration, and being reasonable in cost and not
difficult of use, has been found very serviceable.

Secondly. One or more lenses, also interposed between the mirror
and the object, but perfectly corrected in all respects in the manner
of the best objectives. Of this form the admirable instruments of
Messrs. Beck, Ross, Powell and Lealand, Baker, Crouch, and
others are good examples, as well as, though last not least, the
excellent arrangement of Webster, on and by which most of my
earlier experiments were made. It is very efficient, besides being the
simplest and cheapest form ; no small consideration, I surmise, to

82 DR. MATTHEWS ON A NEW METHOD OF ILLUMINATION.

many who hear me, as well as, I confess, to myself. And here it
is the place and now the time to aver that economy in apparatus
has ever been a prime motive in my experiments, provided that
efficiency and accuracy were not thereby impaired. In this I think
that I have succeeded almost beyond my most sanguine expecta-
tions.

I may just observe, by the way, that we have heard very much
lately of the results of some other mode of illumination, of which
the means have not as yet been published. This is to be deplored,
as secresy is the enemy of true science, and surely that secresy is
unworthy which, while proclaiming results, does not indicate
means !

The great and important question now presents itself of the real
and true meaning of the word definition, since it is that, in com-
bination with resolving power, at which scientific microscopy
should aim. It means, I conceive, to put it as tersely as I can,
" The power of correct appreciation of light and shade in reference
to form, structure, and colour." And its completeness depends
mainly upon the angle at which light is incident on, or passes through
an object, as well as upon the amount and quality of that light.

It was speedily found, as the microscope approached perfection,
that axial light did not fulfil all the conditions necessary for de-
finition, and so men, almost instinctively, turned the mirror out
of the axis, in order to get the effect of oblique illumination, find-
ing that more details were thus secured. Just on this principle,
astronomers observe the moon in her phases instead of at the full,
knowing that in the former case her surface has more of appreci-
able detail.

This was perfectly easy as long as the mirror or the prism in any
form were employed. But when the condenser was substituted,
the conditions altered — the light once more became axial, and then
" definition" was impaired, if it were only from the great increase
of light incident in such a direction that it resembled the examina-
tion of the moon at her full, instead of in one of her phases. To
meet this, certain contrivances were employed called " stops," con-
sisting of a diaphragm so mounted excentrically as to present
certain variously-shaped openings in the axis of illumination.
Some of these were " spots," some mere slits or " slots " in one
azimuth ; others slots in tw # o directions, so as to divide and admit
light in two or more sets of rays.

DR. MATTHEWS ON A NEW METHOD OF ILLUMINATION. 83

The effect was that in the case of the spot stop a hollow cone of
rays resulted ; in others, oblique rays in one, two, or more,
azimuths. Certain markings in so-called test objects were thus
displayed, but no one knows to this hour, with any certainty, what
their nature is, simply because the light which should fall on them
empartially, if I may use the expression, is only used at the will of
the observer, in certain arbitrary directions. No wonder that some
one said to me, very recently, " You can make any appearances you
please with oblique illumination !"

It seems to me practically absurd first to concentrate all the light
you can on an object, then to complain that there is so much, and
in such a wrong direction, that you cannot properly see it ; and
next to proceed to cut off Jths or f ths of that light in the hope
and expectation of seeing better what you want to see ! And yet
this is done every day, when we use a condenser with spots or stops
of any kind. In the spot stop, the case is more peculiarly
unreasonable, for then we get oblique rays certainly; but as
they are in every azimuth at once they must neutralise each, other
in a great degree. I am even of opinion that for this very reason
the means of centering used with condensers were a mistake, and
that they have probably worked at their best, when they were not
centered.

Let us, therefore, go back to first principles. Let us consult
nature.

Let me ask any astronomer when he sees the moon best ? What
is the nature of his difficulties in the observation of the planets ?
Is it not in the first case when she is not in the full, and do not his
difficulties in the second partly result from the opposite reason —
that they are always at the full, the source of light in both cases
remaining unalterable at his will ? I ask of any photographer
when he can get the best effects out of a landscape, when the sun
is behind his camera or at its side ? I think that I need not doubt of
the answer. And now comes the important question. How is
(what I think I may fairly call) this misapplication of that good
thing, the condenser, to be remedied ? I reply, not by interposing
stops or arbitrary openings of any kind in the path of the beam of
light, in order that by cutting off some of its rays, either radially
or centrally, the rest may be left oblique ; but by making the whole
bundle oblique. Let me explain in what way and by what agency.

Mr. Ross lays it down as an axiom quoted by Mr. Hogg on the

84 DR. MATTHEWS ON A NEW METHOD OF ILLUMINATION.

microscope, " That the manner in which an object is lighted is
second in importance only to the excellence of the glass through
which it is seen." This opinion I most heartily endorse, and that
literally, by adopting one of the objectives themselves, of lower
power, as an illuminator in place of a condenser, but not axially.
It must be so mounted as to send the whole of its bundle of rays
at angles varying with the requirements of any given case, and in
this consists the value of the method which I now introduce to
your notice.

Any of the powers may be used, bearing in mind that the higher
the examining, the lower, within convenient limits, should be the
illuminating power, in order to secure a proportionate amount of
light. The only use of condensers of short foci and wide angle is
to get the more oblique rays of the cone by stopping out some
part of the rest. My best results have beeen procured by a two-
thirds or one-and-a-half object glass, which give in all cases quite
sufficient light.

There is no limit for the angle at which the illuminator may be
used in relation to the axis of the instrument short of 90°, sup-
posing both the covering and the mounting glass as well as the
stage to be of no thickness ; but as they all have a very sensible
one, and it is found that rays of a greater angle than about 83° do
not pass through the slide to the object, but are reflected and
lost, I have found it better to work at angles varying from 25° to
65°.

The objections which I have to urge against the use of very
oblique angles of illumination are as follows : — 1st. Supposing
thin covering and mounting glass to be used on wooden slips, the
shadows are likely to be so extended and long as to blend each
with the following, and so confuse the image. 2ndly. That if the
mounting slip be of the average thickness, it serves as a refracting
medium (like the earth's atmosphere during the setting of the sun),
into which rays of extreme obliquity enter ; but from which very
few emerge. And 3rdly, that in both cases much light is lost by the
dispersion of rays over a larger surface than would be covered by
the same number of rays at a lower angle.

You will find a very useful and instructive paper by Mr. Hislop
on this subject in No. 3 of the " Club Journal," to which I refer
you.

In relation to this part of the subject Mr. Ackland has made a

DR. MATTHEWS ON A NEW METHOD OF ILLUMINATION. 85

most valuable suggestion ; viz., to interpose a double concave lens
in the cone of rays formed by the objective condenser before it
reaches the object. There is no doubt that by these means much
light will be saved, since the rays will be rendered parallel, so that
fewer will be reflected by the under surface of the slide of that
part of the cone of light most obliquely incident on it.

And now as to the results. There are, I think, gentlemen pre-
sent who can confirm me in the assertion that they have been most
gratifying and valuable. It was hardly to be expected that in
this — the infancy of the idea— with new manipulations to be as-
certained and mastered, new powers developed and perhaps new
appearances correctly interpreted, this method should exhibit its
superiority as speedily as it has done ; yet at even the very first
attempt I had the pleasure of resolving tests, which had been quite
impossible to me with the same powers previously. I will not
occupy your time by any attempt at enumeration of the objects
which I have thus observed and defined with unusual ease, for I
am of opinion that ocular demonstration is far better. I have,
therefore, placed a microscope on one of the tables, fitted up so as
to show my method, and Mr. Hislop has very kindly promised to
help me. We may not at first, while the management of the in-
strument is new to us, be able to show all that we could wish ; but
I quite believe that we shall, all of us, very soon be able to dis-
pense with other modes of using condensed light. One of its
happy developments is, s that we can at will, effect an excellent dark
ground illumination with objectives of almost any power or an-
gular aperture, by merely adjusting the illuminating power at a
slightly greater angle, easily determined by experiment. I
had hoped to be able to tell you that polariscope effects might
be obtained together with dark ground illumination ; but my in-
vestigations on that subject are as yet so far from complete that
I will not now lay them before you.

The objectives which I have used are some by Beck, Ross,
Powell, and Lealand (an immersion of great excellence), Merz,
as well as one by Mr. Crouch of the same kind, with the per-
formance of which I was much pleased. You will be gratified
to hear that the cost of this useful addition to any microscope
need not exceed 25s., and that a substage is by no means ne-
cessary for its application, while the cost in those instruments not
having one need not exceed 15s. to 20s., and further that any

86

DR. MATTHEWS ON A NEW METHOD OF ILLUMINATION.

intelligent maker can see almost at a glance how it can be effected.
I have hitherto used direct lamp light only ; but it is quite easy
to adapt a prism or mirror for the convenience of those who prefer
daylight. I need scarcely say that I shall be happy to give my
plans for either form to those who may wish it.

I will not occupy your time any further now, for I fear that I
have trespassed too much on your patience already. I had much
more to say, but think that I may well leave it for a future paper,
if the subject prove interesting to you.

Most of those around me know my profession, and may easily
imagine, therefore, how little time I have at my disposal for carry-
ing out investigations which require an uninterrupted leisure. If,
however, what I have said shall induce others who are not similarly
fettered to take up the subject, but with greater skill, knowledge,
and experience than I can pretend to — and I see many such before
me — my purpose in jotting down these observations will have been
answered, and I shall leave this place to-night contented and
happy.

Dr. Matthews' Improved Turn-Table.

87

Improved Turn-table. By J, Matthews, M.D.

(Read 27th May, 1870,;

It may be of interest to members of the Club that I should
describe briefly to them my new form of turn-table, or cell machine,
by which slides are held and centered, as regards their width, at
the same time, leaving their surface entirely free, so that two,
three, or more cells may be formed in their length. Everyone who
has used the present machine must often have felt the inconvenience
of the springs ; sometimes too strong, at others too weak, always
in the way, catching the fingers or the pencil, and limiting the
number of cells. Centering is also so uncertain that several in-
genious remedies have been proposed and used with varying suc-
cess; but none have entirely supplanted the old form devised by Mr.
Shadbolt, now in use. My plan is simple in the extreme, consisting
of two jaws of the average thickness of a glass slide, -| of an inch
wide 2\ long. Each of these is pivotted on the face of the turn-
table by a screw through its centre, each screw being placed exactly
equidistant from the centre of the turn-table, so that the jaws are
separated by a space as wide as an average slide; i.e., a full inch.
Outside of that space, on one side of the centre of one of the
jaws, is a wedge fixed by a screw, in such a way as to be capable
of motion in the direction of its length by a slotted hole. This is
all the machinery. A B and C D are the two jaws, E is the
wedge. On placing a slip between the jaws they probably at
first do not touch it. If the wedge be then pushed so as to
approximate B to C, the jaws move on their centres, so that
however far B may be pushed towards (and moving) C, the
other end of C — i.e. D— is moved exactly as much in the opposite
direction until they approach near enough to grasp the slide by
its edges. The length of the wedge must, of course, be such as
to provide for about -|- of an inch variation in the width of slides.
It will readily be seen that the slip may be pushed in either direc-
tion excentrically lengthwise, so as to allow of the formation of
any number of cells, all of which must needs be central as regards
their width, if the instrument has been accurately made, which is
a very easy matter. I have added also a rest for the hand, F,
which may be turned aside on a centre at will, and which I have
found to be a great convenience. Its price need very little, if at
all, exceed that of the old form.

88

PROCEEDINGS.

March 25th, 1870 — Chairman, P. Le Neve Foster, Esq., M.A.,

President.

The following donations were announced : —

"Science Gossip" ... from the Publisher.

"The Monthly Microscopical Journal" ... the Publisher.

"Land and Water," .• the Publisher.

Four Volumes of "The Popular Science) Dr. R. Braithwaite,

Review" ... ... ... ... ..•■' F.L.S.

Twenty-one Slides of Diatoms in illustration ) M. Alphonse de Bre-

of his paper read February 25th ' bisson.

Two Slides of Hairs of Lion and Mantchurian ? -jy^ q Bennett Junr

J../ I'd at* • a e ••• ••• ••* •••

Seven Slides of Atlantic Soundings, 3,600ft. ? -^ Y -^ rp L ew jg

to 14,400ft >

The thanks of the Club were voted to the donors.

The following gentlemen were ballotted for, and duly elected members of the
Club : — Mr. Edmund Burkhart, Mr. Robert Spring Garden, Mr. Thomas Hyde
Richardson, and Mr. Francis L. Smith.

Mr. M. C. Cooke read a paper " On Microscopic Moulds," which was illus-
trated by a large' number of coloured diagrams and by specimens exhibited
under the microscope at the close of the meeting. A quantity of specimens of
several kinds of Fungi were placed upon the table for distribution amongst
those members who felt interested in the subject.

The President proposed a vote of thanks to Mr Cooke for his very interesting
paper, which was carried by acclamation.

Mr. Edward Richards exhibited and described a newly-devised method of
using Darker' s Selenites, by which the different films were placed entirely under
the command of the observer— the construction of the apparatus was rendered
more intelligible by a large model in wood, and the practical application of the
various combinations was shown to the members at the close of the meeting.

The President said that all the members who were present at the recent
Soiree must have a very grateful sense of obligation to those gentlemen who
exhibited objects on that occasion ; he, therefore, asked for a vote of thanks to
them for their efforts on that occasion.

Dr. Braithwaite seconded the proposal, which was carried nem. dis.

The President said that members would, no doubt, recollect that a fresh
arrangement with regard to the issue of the tickets for the Soiree had been
carried out this year. It had been found that on former occasions the crowding
was very great ; and to prevent this it was this year resolved that only one
complimentary ticket should be given to each member, but that any members

89

who wished to bring other friends could be supplied with additional tickets at
2s. 6d. each. It was not intended by this arrangement to put money into the
pockets of the Club, but merely to restrict the number of tickets issued. On
this occasion the money received for the sale of tickets amounted to £5 7s. 6d.,
and the Council have resolved to present this sum to the funds of University
College Hospital (great applause). The manner in which you have received this
announcement shows how heartily you approve of the manner in which this
amount has been applied.

The President announced the meetings and field excursions for the ensuing
month, and the proceedings terminated with a conversazione, at which the
following objects were exhibited : —

Poppy Seed by Mr. Golding.

Test objects, shown with new immersion £in.

Borate of Ammonia, crystallized in various I

I Ol lllo • * • ••• »*« • » • *•• • • •

JDiaptomus Castor (a fresh-water Crustacean), \

and Botryosporium pulchrum i

Euglena Viridis

New Apparatus for using Darker' s Selenite 7

J. J.J.IJI0 *«• ••• ••• •■• ••• •••

New and Compact Binocular Microscope, 1
specially designed for travelling ■>

Mr. H. Crouch.
Mr. G. Conder.

Mr. Hainworth.

Mr. Martinelli.
Mr. Richards.

Mr. Moginie.

April 22nd, 1870 — Chairman, Dr. R. Braithwaite, F.L.S., V.P.

from the Publisher,
the Publisher,
the Publisher,
the Editor.
the Publisher,
the Association.

the Royal Microsco-
pical Society.

The following donations were announced : —
* c The Monthly Microscopical Journal "

" Science Gossip "

" The Popular Science Review"

" Land and Water" (weekly)

"Good Health," Nos. 8, 9, 10

Annual Report of the Geologists' Association

" De laMotilitie des Conferves"

Descriptive Catalogue of 100 Objects exhibited")

at the Soire'e of the Royal Microscopical |

Society, and List of 60 Objects from Y

Deep Sea Dredgings, exhibited by Dr. W. {

B. Carpenter J

Proofs of Illustrations to be published with 1

Mr. Suffolk's Lectures '

One Slide— Gizzard of Cockroach
Four Slides— Borate of Ammonia
One Slide— Starch of Calabar Bean ...
"The American Naturalist," vol. iv., Nos.

A. CL1J.U. _j • • • ••* ••• ••• ••

The thanks of the Club were voted to the donors.

The following gentlemen were ballotted for, and duly elected members of the
Club :-Mr. William Adams, F.R.C.S., Mr. A. Horsley Bossy, Mr. Charles
Barrett Barnes, Mr. William Black, Mr. John Foster, Mr. John Michels, Mr.

Mr W.

Mr. T.
Mr. G.

T. Suffolk,

C. White.
Condor.

in Exchange.

90

Alfred Green Lang, Mr. Thomas Jeffery Parker, and Mr. William Ford
Stanley.

Mr. N. E. Green read a paper " On Ciliary Action in Infusoria and Floscu-
laria," illustrated by a diagram.

The Chairman proposed a very cordial vote of thanks to Mr. Green for his
paper, which was carried unanimously.

A member observed that Mr. Green had mentioned a little difficulty, which
had frequently occurred to himself, and that was the pronunciation of scientific
terms ; for instance, the e in Genus was pronounced long in the singular, but
short in the plural ; and in the word Fungi, some people made the g hard and
others soft. He had often felt puzzled as to which was correct, and should be
glad to know if there was any rule for guidance in such cases. He mentioned
the subject to Dr. Carpenter a short time ago, and the answer to his inquiry
was, " Well, there is no accounting for these things."

The Chairman said that there was really no guide in such cases as those men-
tioned. There were certain rules as to quantities where a vowel comes before two
consonants, final es, and some other instances, but beyond these the matter
greatly depends upon custom or taste.

Mr. Hainworth inquired of the reader of the paper what illumination was used
with the one-sixth inch objective with which he saw the cilia ?

Mr Green replied that he used a condenser with the usual illumination.

Mr. Curties believed that Mr. Green used an ordinary objective as a condenser.

Mr. Green said he used an ordinary jin. objective, adapted by Dallmeyer for
the purpose.

Mr. White said that having heard how to observe the Floscularia, no doubt
many of the members would be glad to know where to get them. The round
pond in Kensington Gardens was a place where they were very abundant, and
he had obtained them from it at all times of the year.

Mr. Gay said this pond used to be a good place for them, but that he had
tried several times lately and could not find any there.

Dr. Braithwaite suggested that it would be a question whether these cilia were
common to all infusoria.

The Chairman said that he wished to bring under the notice of the members
the formation of a new Microscopical Society at Croydon. Mr. Henry Lee, the
President, was a member of this Club, and at the first meeting of the Society
nearly a hundred members were enrolled. No doubt they would have excursions
during the season, which, he thought, might be made mutually advantageous by
arrangements to join with the Club on different occasions.

The Secretary mentioned that he had been told that the Croydon Society
were looking forward to the excursion of the Club to Carshalton on May 14th,
in the hope of being able to join with our members there ; he was sure that by
uniting in this way the usefulness of these excursions would be increased, and
mutual information gained.

The following objects were exhibited : —

Melicerta ringens

Fredricella Sultana

Gizzard of Cockroach

Gizzard of Cricket

Diatoms Mounted Opaque, by Moller

by Mr. Hainworth.
Mr. Oxley.
Mr. T. C. White.
Mr. Quick.
Mr. Curties.

Mr. S. J. Mclntire said that he had never seen the gizzard of the Cricket ex-
hibited so nicely as in Mr. Quick's specimen — it was transparent and cut
circular.

91

May 27th, 1870 — Chairman, Dr. R. Braithwaite, F.L.S., V.P.

The following donations were announced : —

" The Monthly Microscopical Journal" from the Publisher.

"Science Gossip" the Publisher.

" Land and Water " (weekly) the Publisher.

Eeport of the Surgeon General U.S.A. on the

Magnesium and Electric lights as applied / .

, & „. , , . -i i V Lieut.-Colonel

to Microphotography, accompanied by > _ ,

eleven Photographs in illustration of the

results obtained by both means.

Two Slides. Sections of Granite from Mount") -^ j^^g

Olll ell* ■•• ••• ••• ••• ••• J

Twelve Slides. Various Mr. Quick.

The American Naturalist, Vol. iv., No. 3 by Exchange.

The thanks of the Club were voted to the donors.

The following gentlemen were balloted for and duly elected members of the
Club : — Mr. H. G. Brigham, Mr. George Dransfield Brown, Mr. Henry Hay ward,
Mr. T. W. Home, Dr. Henry Medlock.

Mr. Waller read a paper ' ' On the Conjugation of Actinophrys Sol," illustrating
the subject by diagrams.

The Chairman was sure that all would join him in proposing a hearty vote of
thanks to Mr. Waller, for his able and interesting paper, which was a challenge
thrown down to members, so many of whom at this season of the year were
engaged in collecting. They would, no doubt, notice that it was not sufficient
to look at the specimens and then throw them away j they must keep on ob-
serving them carefully at short intervals to meet with success. There had been
many writers upon this subject — one of the principal writers, Kolliker, does not
allude to this method of conjugation described by Mr. Waller, but refers their
reproduction to the process of gemmation. Dr. Wallich, however, in 1863 —
some time after Mr. Waller had made his observations— noticed this process,
and thought at the time that it was fission taking place ; but on looking a short
time afterwards he saw that the two individuals had become one, and then he
became satisfied that it was conjugation, but he did not appear to have noticed
the escape of the small bodies seen by Mr. Waller. These observations were
very interesting, from their bearing upon the question of the distinctions
between the animal and vegetable kingdoms. Some of the small algae or fuci
were known to reproduce by conjugation. No one else appeared to have seen
the eruption of granules observed by Mr. Waller ; it was a most interesting ob-
servation, which, it was hoped, would be repeated, so that an opportunity might
be given for examination with higher powers than those yet employed, for the
purpose of ascertaining whether they were furnished with cilia. With regard
to the leaping of a species, to which reference had been made in the paper, he
believed it might easily be explained by the elastic nature of the Pseudopodia,
the motion caused by which might easily be mistaken for a leap, under the
microscope.

Mr. T. C White expressed the happiness he had in seconding Dr. Braith-
waite's vote of thanks, and he hoped that many of the members would follow
the example of Mr. Waller, who had not only made a series of careful observa-
tions, but had also made drawings of what he had seen— a matter of very great
importance. It was suggested some time since, after the reading of a paper by

92

Mr. Draper, that there should be a Quekett Club Portfolio, to contain the
drawings made by members from their original observations, and he was very
desirous of seeing this suggestion carried out. Mr. Waller further deserved the
thanks of the meeting for his desire to be a iiseful member of the Club ; he
hoped that many more members would be stimulated with the same desire, and
would give the results of their observations to the members at the meetings —
there need be no fear that subjects might not be interesting, for all might rest
assured that, if interesting to themselves, it could not fail to be interesting to
others when communicated ; for interest in a subject was undoubtedly catching.
Dr. Matthews introduced and described a new form of turn-table, and read a
paper " On a new method of sub-stage illumination."

The Chairman, in moving a vote of thanks to Dr. Matthews, expressed the
pleasure he had felt in listening to his remarks, and characterized the improved
form of turn-table as one of the most ingenious contrivances he had yet seen for
the purpose.

Mr. S. J. Mclntire said that he had the pleasure a short time since of spending
an evening with Dr. Matthews, and was much pleased with the results obtained
by the new method of illumination. He had himself been for some time working
with one of Powell and Lealand's achromatic condensers, and took this with him
for comparison, but was not very successful in using it on that occasion. He
would not, however, say that the new method was better than his own condenser,
but the difference in the cost was considerable, being only that of the means for
fixing one's own object-glass below the stage, and he might say that thus the
best results could be obtained for twenty-five shillings.

Votes of thanks to Mr. Waller and Dr. Matthews were then carried
unanimously.

Mr. Curties said that he had the misfortune to be one of those persons
described by Dr. Matthews as "fettered beings," but he had however been able
recently to make an excursion on his own account, and it was to the Admiralty,
at Whitehall. Having to wait some time he found that one side of the waiting
room was covered by a picture containing about 600 microscopic forms drawn by
Lieut. Palmer, during one of his voyages. Feeling sure that this waiting-room
was not well known, he thought it would be a matter of interest to many of the
members to hear of what was to be seen in it. The picture is of large size and
represents many forms from the animal kingdom, as well as those of surface
ocean life and microscopic life met with during the voyage ; in addition to the
objects there is a chart showing the course of the vessel, every care being taken
to give the temperature of the water with the latitude and longitude where the
dredgings took place. In reply to a question from Mr. Ruffle, Mr Curties also
stated that the picture could be viewed by any person who visited the place.

The Chairman directed the attention of the members to a very valuable
addition to the library of the club, the whole of the First and Second Series of
the Annals of Natural History, which had been recently purchased at a mode-
rate cost, and which could not fail to be of great service to many members as
works of reference.

The Secretary announced that the following objects were exhibited : —
Teeth of Leech ... ... ... ... by Mr. Conder.

Test objects, shown by the new mode of sub-) -p Matthews

stage illumination ... ... J

Head and Eyes of Spider ... ... ... Mr. Golding.

Special attention was also called to a number of very beautiful coloured draw-
ings of the eggs of Lepidoptera and other microscopic objects kindly lent for
exhibition by Mr. Millett. R. T. Lewis.

93

Observations on the Conjugation of Actinophrys Sol.

By John G. Waller.
{Read 27th May, 1870.)

I feel some diffidence in communicating the result of observa-
tions made just nine years ago, beeause, in that interval, the number
of observers with the microscope has so greatly multiplied that
I cannot hope to tell you much that is new. But the subject is of
acknowledged obscurity, as, indeed, is the case with the life his-
tory of all those humble organisms that seem to stand at the
base of animal life. If, therefore, I merely confirm the observa-
tions of others, some little service may be done. Moreover, I have
no hypothesis to support ; all I undertake to do is to record what I
saw and what I noted down with my pencil and pen at every stage.
I shall also show you that, at the time my observations were made,
there was no certainty among those, either at home or abroad, who
had written upon the subject, but merely a chaos of conflicting
evidence.

In April, 1861, I paade a gathering at Woodford Bridge, in the
river Roding, and the ditches adjacent. It was a very rich one. It con-
tained diatomaceee and desmideacese in abundance, as well as many
other specimens of microscopic algas. Two varieties of hydra — Hydra
vulgaris and Hydra viridis. Two or three varieties of amoeba, with
many allied organisms, amongst which was the Actinophrys Sol (Sun
animalcule), taken from a dusty scum on the surface of a ditch. Being
more interested at that time in diatoms, I did not at first pay so
much attention to this particular gathering, and did not examine
it completely until May 7, when, in putting a drop of water upon a
slide, I discovered six individuals of the actinophrys grouped to-
gether around an empty cyst, in the midst of which was a small
diatom. (PI. x. Fig. 1.) I at once made a drawing of it, and observed
it for some time ; not, however, noting anything more remarkable
than that all seemed adherent together, floating without any volun-

Journ. Q, M. C. No. 12. h

94 JOHN G. WALLER, OBSERVATIONS ON THE

tary motion, either as a whole or in the individual members ; ex-
cept, however, and this is important to note, that the six indi-
viduals were really in three conjugating groups, and each group
did change slightly its relative position, but it was by a passive
kind of motion, backwards and forwards, showing that the bodies
were only adherent together, and had no such union as was the
case with the pairs conjugating ; and I am inclined to think that
the group, together with the empty cyst, may have been an acci-
dental circumstance, and was not connected with the life history of
the organism.

I was, however, unable to conclude my observations thoroughly,
being called away, and the water evaporated before I could return
to it, as it was not covered. But my interest was now fairly roused.
I took another drop of the water, and finding many of the animal-
cule conjugating, made a drawing of one example, which seemed
as in the act of separation. (Fig. 2.) One individual exhibited a
protuberance or budding, as if in gemmation; but whether that
had any relation to the phenomenon of conjugation I had no means
of proof; what I observed in this instance being merely the act of
separation, which I watched until its completion, making drawings
from time to time. (See Figs. 3, 4, 5, 6, 7, 8.) It was slow and
gradual, and apparently effected chiefly by the mere force of gravi-
tation. As it proceeded to completion the band of union became
more and more -attenuated ; at length it twisted in opposite direc-
tions, much as one twists a piece of thin cord to break it, and finally
portions of it snapped asunder, and then each gradually withdrew the
broken band into its own substance. During the extension of the
band, and also in the peculiar manner in which it ultimately broke,
leaving a ragged edge, I recognised a remarkable semblance to
India rubber when a small piece is drawn out until it breaks, and
thence concluded the substance to be very elastic. I did not wit-
ness any further phenomena, although I watched for some time the
individual which seemed to be in the condition of gemmation.
In fact, here again I had been careless enough not to protect
the water from evaporation, and it dried up just as I had noted an
increased development in the gemmule, and had recorded it by a
drawing. (Fig. 9.)

The question now arises, and which is one of the difficulties of
the subject, was it fission or was it conjugation, with the result a
gemmule and a subsequent separation, that I had witnessed ? I did

CONJUGATION OF ACTINOPHRYS SOL. 95

not see, either the beginning or, in fact, the complete ending. Nor
do other observers, as far as I am aware, appear to have been more
fortunate. If fission, it can be understood by analogy, but if con-
jugation, I shall be able to show you that it has another and a very
different issue.

On the following day I made another observation, and one by
far the most interesting, and to which I especially direct your at-
tention. This time I took care to avoid untimely evaporation,
and placed the water upon the capillary tablet.

In this instance, I was attracted by noticing that an apparent
change was taking place in two individuals in the act of conjuga-
tion. I remarked that the tentacular processes were being with-
drawn, and that a more intimate union of the two coalescing bodies
was taking place. Having satisfied myself of the fact, I made a
drawing of this stage. (Fig. 10.) It was 4 o'clock p.m., and I
watched the object from time to time until 7 o'clock, when scarcely
a vestige of any of the processes were visible, and the two bodies
had become one, ovate in form, but still retaining a mark of separa-
tion. (Fig. 11.) Half an hour afterwards there was but little of
such mark left (Fig. 12), aud three hours after that, viz., at 10.30
p.rn., it was one circular mass, with but a slight remnant of the
tentacular processes ; all had been withdrawn. (Fig. 13.) On the
following morning at 8 o'clock there was but little apparent dif-
ference, only that neither processes nor retractile vesicle were now
visible. About half an hour afterwards, I noticed a slight fidgetty
movement going on in the interior of the substance, like as if some
nrinutebodies were endeavouring to escape, which gradually increased
until they burst forth, (Fig. 14), having arapid gyrating movement,
which, as they came into focus, showed them to be ovate in form, and of
a dirty yellow colour ; but whether ciliated or not I could not detect.
They poured forth so rapidly, and in such numbers, as to fill the
field of the microscope, until at length a pellucid envelope seemed to
burst, portions being protruded at each end, which spread out
exactly as an amoeba ; indeed, anyone would then have imagined it to
have been that organism. This took place at 9.30 (Fig. 15) ; a short
time afterwards the operation ceased ; the portions protruded like
pseudopodia were withdrawn again into the substance, which now
became quiescent, but was very different in appearance and
character. It seemed to be a circular mass of coarse granules,
without any sign of life, and of a rough irregular outline, and had

h 2

96 JOHN G. WALLER, OBSERVATIONS ON THE

lost its colour (Fig. 1G). Thus I left it at 10 o'clock, and through-
out the day not the slightest change took place. I let it remain
under observation for twenty-four hours, but it was still the same ;
and it was obvious to me that all life had ceased, as not a particle
changed either its form or position.

I now sought for information on the phenomena I had witnessed ;
and taking down from my shelves the last edition of Pritchard's
" Infusoria," proceeded to examine the summary there given of the
knowledge of this interesting organism ; and on which I think
myself entitled to offer some criticism, and first on that division
which treats of " conjugation."

" The remarkable act of conjugation," says the editor, " also
known as Zygosis, has attracted very much attention in the class of
animalcules under consideration, among which it is of frequent
occurrence. Much discussion has taken place concerning the pur-
pose of this process. Most of its early observers considered it a
reproductive act, a sort of copulation between the two individuals ;
but the tendency of opinion at the present day is to deny it this
nature, and to treat it as little more than an accidental phenomenon,
without apparent object or aim. Nevertheless, its occurrence is so
frequent, and the process of so complete a character, that it is hard
to believe it to be in vain, and to no purpose in the economy of the
Actinophryina." Surely the observations here given endorse
the correctness of the latter view. But the writer proceeds to say,
" A difference of opinion likewise prevails as to the nature of the
process, one set of authors maintaining that there is an actual
' fusion and intermingling of substance between the conjugating
animals, whilst another party asserts that there is no fusion, but
merely a temporary adhesion or accretion between their bodies."
Kolliker describes this fusion, and speaks of it as of a reproductive
character. The facts I have given you seem, to my mind, to point
to the same conclusion ; but the summary in Pritchard's " Infusoria"
concludes in this most indecisive manner : —

" The balance of authority and evidence is against the supposi-
tion of its reproductive purpose ; but when this view is rejected, we
have no other to replace it, and are sensible of the want of sufficient
data from direct observation before a hopeful attempt can be made."

You have before you the result of conjugation producing, I think
I may presume to say, " embryonic germs," this term being one I
take from several observers who have evidently seen at least this

CONJUGATION OF ACTINOPHRYS SOL. 97

part of the phenomenon, although some may have somewhat incor-
rectly described it. Stein, Kolliker, and Mr. Weston all maintain
that there is a reproduction in " Actinophrys" by " germs." That
the minute ovate bodies were living beings there cannot be the
smallest doubt ; what their development is remains a problem, to
be solved, I hope, by some members of the Quekett Club.

Now, then, as to what is called " fission." The separation of two
individuals, such as I have described, seems to be the same pheno-
menon that some eminent observers have termed " fission." If so,
the term " conjugation" must not be applied here. But my observa-
tion gives us no proof, as I did not see the commencement of the
phenomenon, and it is a point well worth the attention of our
numerous members. The difficulties in the investigation, and the
diversities of opinion, arise from observers not seeing the beginning
and the end. If the instance I have given of separation was after
conjugation, it would show gemmation as a result, for a gemmule
was developing itself. If, on the contrary, one of the separating
bodies was already developed from gemmation, it would settle one
question — viz., as to whether gemmation was indeed one result of
conjugation ? Nothing that I have seen written is at all satisfac-
tory on this head, and my hope is in our numerous observers, and
that there may be many present whose researches may throw light
upon this interesting question.

The phenomena of gemmation and fission, as also of conjugation
and of embryonic germs, if the ovate bodies I have mentioned come
under that denomination, is witnessed in many organisms directly
allied to the Actinophrys Sol; it would surely, then, be mostunphilo-
sophical to deny either of the phenomena to be a part of the life
history of this organism.

Whilst upon the subject, I may mention that a writer in the Trans-
action of the Microscopic Society* (Mr. Boswell) has asserted that
the power of suddenly taking a leap exists in the Actinophryina. I
do not believe this can be said of the Actinophrys Sol, for out of
hundreds of examples I have never witnessed a single act of rapid
motion. But there are organisms so very similar in appearance,
that may or may not be (I believe they are) classified under the
Actinophryina. One of these I have figured, of a pearly grey
colour, found in Swanscombe Marsh, having very short but much
more numerous processes than the Actinophrys Sol ; and this I have

*1854 } p. 25.

98 OBSERVATIONS ON THE CONJUGATION OF ACTINOPHRYS SOL.

frequently seen to whisk out of the field with a rapidity like light-
ning, in this case using the processes as motive organs. I think I
have also noticed this fact in one of a bright green colour, found at
Hampstead, as well also in one of a grey tint found in the same
locality. These have no contractile vesicle that I have seen ; they
are not found in abundance as far as my experience goes, and their
being classed with the Actinophrys Sol may be due only to their
resemblance in shape. My belief is they are larval forms of other
creatures.

Among my drawings of the 8th May, 1861, from the same
gathering, was one very small object, white and transparent in
substance, with tentacular processes like the actinophrys, of which
it may have been an early stage. I exhibit a drawing of it, bear-
ing its relative size to the other forms (Fig. 17). I have brought
forward this subject now for two reasons — first, because this is the
time of the year to pursue this investigation for those who may be
interested in it ; secondly, because I do not wish to be quite an
idle member of the Club.

Plate X. Illustrates this Paper %
EXPLANATION OF PLATES,

ILLUSTRATING MR. F. KITTON's PATER.

Plate II.

Figs. 1 and 6, Trinacria Eegina, side view; 2, outline of base (grund fladen) j
3, outline of base (side view) ; 4, side view of frustule ; 5 and 7, side views of
valve.

Plate ILL

Fig. 1, Corinna elegans, front view of frustules in series ; 2 and 3, front view
of valve ; 4, transverse section of valve ; 5, transverse side view of valve.
6 and 7, Trinacria excavata, side view of valve ; 8, front view of valve ; 9, front
view of frustules in series. 10 and 15, Solium exsculptum, side views of valves ;
11 and 13, front views of valves ; 12, front views of frustules in series; 14, side
view of valve, inner surface.

Plate XI.

Fig. 1, Hemiaulus Proteus, front view; 2, side view of valve, inner surface
(grund fladen) ; 3, side view outer surface (Hoved fladen) ; 4, valve as seen edge-
wise (Iva^rsmittet) ; 5, front view of large valve ; 6, front view of small valve,
7, Hemiaulus liostilis, front view; 8, front view of two opposite valves (small) ;
9, side view of valve, inner surface ; 10, side view of valve, outer surface ; 11,
valve as seen edgewise. 12, Hemiaulus februatus, front view ; 13, front view
small valve; 14, side view, inner surface; 15, side view, outer surface; 16, valve
as seen edgewise.

99

DlATOMACEOUS DEPOSITS FROM JUTLAND.

By F. Kitton.*

The remarkable deposits found in and near the island of Mors
have lately attracted the attention of microscopists (principally
through the introduction of the beautiful slides of Herr Muller, of
Wedel, the preparer of the Typen Platte). This deposit, with
perhaps one exception — the so-called " Bermuda Earth ' (New
Nottingham deposit) — is richer in bizarre and beautiful cliatomaceous
forms than any other hitherto discovered. The material best
known in this country is that called " Cemenstein," from the island
of Mors, a large island situated in the Liimfjord (lat. 56° 50' N.,
long. 8° 40' W.). This fjord, the most extensive in Jutland, runs
from east to west, connecting the North Sea with the Kattegat.
The Cementstein from Mors resembles a dark grey slate, inter-
spersed with white veins. The silicious organisms of which it is
chiefly composed are held together by a calcareous cement, and
when submitted to the action of acids are slowly disintegrated with
effervescence. A similar deposit occurs in Fuur ; it is, however,
more difficult to separate, and but slightly affected by acid, and
resembles the deposit known as " brown coal." A third deposit is
found in Nykjobing, a small town or village on the western side of
Mors Island. This deposit is of a greyish white colour, still more
difficult to reduce than the preceding, strong acids not affecting it
in any appreciable degree, and only by the assistance of caustic
potash or soda can the organisms of which it is composed be
effectually separated-. One of these deposits seems to have been
known to Professor Quekett, as he figures a small Triceratium in
his " Histology " (vol. ii., p. 74, fig. F), and which is apparently a
small form of Trinacria excavata, similar to the variety found in the
Nykjobing deposit ; this, the Professor says, is from "Jutland slate."
Dr. Heiberg, in his " Kritisk oversigt over de Danske Diato-
meer," describes a few of these deposit-forms, and also gives some
excellent figures of them.

* Communicated by M. C. Cooke, M.A., June 24th, 1870.

100 P. KITTON ON DIATOMACEOUS DEPOSITS FROM JUTLAND.

Dr. Heiberg, in the above-mentioned work, proposes a new
family, based on the genus Hemianlus of Professor Ehrenberg, a
genus well represented in the Barbadoes deposits. The species of
this genus bear a superficial resemblance to the genus Biddulphia,
but ajiproach nearer to some forms hitherto considered as Trice-
ratia. The following is Dr. Heiberg's synopsis of the family: —

HEMIAULID.E HEIBERG.

Frustules uniform, front and side views always symmetrical,
nearly rectangular in front view, with long horn-like (hyanes-
tillede) processes terminating in one or two straight or inclined
spines, the processes straight on the outer margin, forming a right
angle with the base of the valve (en ret Yinkel mid Skallens
Grundflage). Sculpture consists of larger or smaller punctas ;
variously arranged costse are sometimes present ; markings of
connecting zone (Bindehinden) less conspicuous.

Tribus I. — Hemiaulidce genuince.
Outline of side and front views symmetrical, both in longitu-
dinal and transverse axes, or if more than two axes symmetrical
with all of them.

Genus 1. Hemianlus. Ehr.
Outline of valve elliptical (lanceolate oval), produced at the
longer axes into horn-like processes, the points of which are pro-
Tided with a spine (een Torn).

.Genus 2. Trinacria. Heiberg.
Outline of valve with three* equal angles (with axes of equal
value), front view of frustule with three horn-like processes, each
terminating in two spines.

Genus 3. Solium. Heiberg.
Outline of valve regularly quadraticf or rhomboid, frustules in
front view with horn-like processes at the corners, and terminating
with two spines.

Tribus II. — Hemiaulidce cuneatw.
Outline of valve oval (asgdannet), front view wedge-shaped,
frustule only symmetrical in the long diameter.

Genus 4. Corinna.
Outline of valve regularly oval, with two horn-like unequal

* This character of the Author must be enlarged if of any generic or specific
value, as Trinacria regina occurs with four sides.

t The preceding remarks apply to this genus. In the Fuur material we
find Solium exsculptum with five angles. For specimens of this form I am
indebted to G. M. Brown, Esq., of Liverpool.

F. KITTON ON DIOTOMACEOUS DEPOSITS FROM JUTLAND. 101

processes, of which the larger occurs at the broadest part of the
frustule ; both are armed with two spines.

Hemiaulus Proteus (Heiberg). — Frustules in series, cohering at
the produced angles, each of which are armed with a stout curved
spine ; space between the angles with a large central inflation, and
one or more smaller inflations on each side, decreasing as they
approach the angles. Side view elliptic, lanceolate centre widely
constricted, and four or more costee (the costee correspond with the
depressions seen in front view) ; cellules scattered, distinct.
(Cementstein Mors, brown deposit, Fuur. PI. xi., fig. 1-6.)

Hemiaulus hostilis (Heiberg). — Frustules in series cohering at
the angles ; processes elongated, terminating in a slender, straight
spine ; one large central inflation between the angles ; side view
oval, with two costee ; cellules scattered, distinct, smaller, and closer
in centre (between the costee) ; Cementstein Mors, brown de-
posit, Fuur, rare in Nykjobing deposit (pi. xi., fig. 7-11.)

Hemiaulus februatus (Heiberg). — Frustules in series ; processes
terminating in a stout, curved spine ; space between the processes,
with a single inflation ; bases of processes suddenly inclining to-
wards the inflation ; side view ovate ; costee, two ; cellules large,
moniliform, very conspicuous in the centre (between the costal), in
all the preceding deposits (pi. xi., fig. 12-16.)

Trinacria Regina (Heiberg). — Frustules in series cohering at
the processes ; processes produced hornlike at right angles to valve,
tipped with two incurved spines ; valves with three or more sides,
slightly concave ; outline slightly undulate ; marking consisting of
conspicuous pearl-like granules, distant and scattered near the
smooth centre, but distinctly radiant as they approach the margin ;
common in the Cementstein Mors and Fuur deposit, scarce in the
Nykjobing deposit (pi. ii., fig. 1 to 7).

Trinacria excavata (Heiberg). — Frustules in series ; processes
long, at right angles to valve, armed with two incurved spines ;
valves, with margins, deeply concave ; granules distinct, radiating
from the centre ; Cementstein Mors brown deposit, Fuur ; the small
variety occurs in the Nykjobing deposit (pi. hi., fig. 6 to 9).

The small form (fig. 7) is probably identical with Triceratium
ligulatum of Dr. Greville (Trans. Mic. Soc, vol. xii., pi. 13, fig. 9.)
The larger form I have no hesitation in referring to T. Solenoceros*

* Dr. Heiberg says in his Danske Diatomeer, "Kan jeg ikke antage Andet
end at Brightwell har hav enfra neervserende Art faskjellig Form for sig " (page
51).

102 F. KITTON ON DIATOMACEOUS DEPOSITS FROM JUTLAND.

Eh., and T. Kittonianum Grev. (see Trans. Mic. Soc, vol xiii., page
1, pi. 2, fig. 18) ; a careful examination of the deposits in which
Ehrenberg found his specimens has afforded me an opportunity of
observing many valves perfect and fragmentary ; and I find the
"pseudo-nodules" are more or less distinct in all of them. The
differences between T. Solenoceros and T. Kittonianum, which Dr.
Greville says are so very decided, are really of no specific value ;
the pseudo-nodules (processes as seen in side view) are not absent
in T. Solenoceros, excepting in the figures in the Microgeologie and
Mr. Brightwell's monograph of the Triceratia. I have examined
Mr. Brightwell's slides, and although the processes are not very
distinct, they may be detected. In the same paper Dr. Greville re-
marks that the pseudo-nodule is very conspicuous in T. Kittonianum,
and he quotes my sketch of the front view, in which he says it
11 projects above and below the connecting zone like a hammer:"
this character further identifies it with Trinacria excavata.

Solium exsculptum (Herberg). — Frustulesin series cohering at the
angles ; processes at right angles to surface of valve tipped with
two curved spines ; space between the processes inflated ; valves
with four or more sides ; angles produced mammiform ; costate at
base ; cellules small, slightly radiant ; Cementstein Mors, brown
deposit, Fuur, Nykjobing deposit (pi. iii., fig. 10 to 15).

This remarkable form seems to bear the same relation to Amphi-
tetras as Trinacria does to Triceratium ; in the Fuur deposit valves
with five angles are not uncommon.

Corinna elegans (Heiberg). — Frustules wedge-shaped in series co-
hering at the angles ; processes two, unequally produced, armed
with a short spine ; inner margin of process slightly undulated ;
centre conspicuously inflated ; valve ovate, apiculate ; cellules
small, radiant. Common in the Cementstein Mors, brown deposit,
Fuur, Nykjobing deposit.

A very curious form, closely allied to Hemiaulus, from which,
however, it is separated by the two unequal processes. The long
process of one frustule is attached to the long process of the next
frustule, and thus forming a curved filament. The Hemiaulus pul-
vinatus of Greville greatly resembles this species.

In a future paper I hope to describe some of the discoid and
other forms occurring in these deposits.

103

Valedictory Address of the Ketiring President,

P. Le Neve Foster, Esq., M.A., F.R.M.S.

{Delivered July 22, 1870.)

Gentlemen, — Five years ago, the Quekett Microscopical Club
consisted of eleven members ; it now numbers upwards of five
hundred. At first we were looked upon somewhat coldly by our
elder brethren, simply because our aims and objects were not
understood, and because we were supposed to be antagonistic to
existing institutions. When once, however, it was explained that
we were not a revolutionary body, but were purely a band of earnest
workers, desirous of extending the benefits of scientific combination
to many who, from a variety of causes, could not or did not feel
themselves sufficiently advanced in the study of microscopy to join in
the gatherings of their elders, all suspicion vanished, and the hand
of fellowship was cordially extended to us. Our success arose from
two causes : — First, we represented a want ; and, secondly, we
were under the guidance of zealous and energetic helmsmen, who
not only had the sagacity to lay down the right course for our
newly-launched vessel, but kept her head steadily to it. Among
these I must specially name our late Honorary Secretary, Mr. By-
water, for to his exertions mainly in our early years must our
success be attributed. We all know, in these undertakings, how
much depends upon the work of one man ; with tact and skill he
gathers around him the necessary elements for accomplishing the
objects he has at heart. Mr. By water stuck to his post until the
Club had become so great a success that he could hand it over in
complete working order to his successor. While we regretted the
loss of his services as Secretary, we rejoiced to retain him, for
counsel and advice, as one of our Vice-Presidents ; and it must be
a source of gratification to Mr. Bywater to know that his labours on
behalf of the Club have been thoroughly appreciated by all the
members. The testimonial which was presented to him on his re-
tirement was indeed well earned, and though I could not claim the
privilege of presenting it, that duty properly falling to the lot of

104 THE PRESIDENT'S ADDRESS.

my predecessor in this chair, under whose auspices it had been set
afloat, yet it gave me unfeigned pleasure that one of the first
public acts which took place after my election to the chair of this
Society should have been of so agreeable a character. Gentlemen,
while I thus speak of the success of the Club, and of the numbers
which now swell the list of its members, we must not forget that
numbers, though in some degree a test of success, are not every-
thing ; we must look to what we are doing in the way of promoting
the science we are banded together to assist. Are we doing all we
can, all we ought? I scarcely think that we are. I am disposed
to think that we do not take sufficient advantage of our organi-
sation. We are not sufficiently systematic in our proceedings.
We must bear in mind that, however agreeable, and even
useful, it may be to meet and gossip about this or that
at our monthly and fortnightly meetings, and listen to a paper
on some isolated point, that is not the end and object of our
Society. We should remember that we are essentially a student
body, and I could have wished at our meetings that there could
have been more discussion to follow the reading of our papers.
This want of discussion is evidence that the subject has not suffi-
cient hold on the labours and investigations of others to call forth
inquiry and debate. This, as I have said before, arises from a want
of system in our proceedings. A paper on some special subject,
or branch of a special subject, is brought before us without pre-
vious concert with others ; it comes frequently before us without
previous notice, possibly no one else has been pursuing the same or
kindred train of investigation, and there is consequently no one
capable of adding to the common stock of knowledge ; the paper is
too apt to fall dead, without interest, and obtains no further notice
till it is read, or perhaps not read, some months afterwards in our
Transactions.

The Club has no doubt accomplished great good in diffusing the
taste for microscopical investigation, and in facilitating the communi-
cation of results, but room is still left for suggestions as to en-
larging its usefulness. In the face of existing scientific societies,
the grounds for establishing new ones are two -fold — first, affording
other facilities for the acquisition of new truths ; second, the ex-
tension of the cultivation of the particular science amongst
persons not comprised in the elder society. Each body then
should have its own characteristic, so as to ensure its occupying its

THE PRESIDENT'S ADDRESS. 105

own special ground ; otherwise the societies tend either to become
rivals, whence a waste of scientific power, or pale reflexes of one
another mutually deteriorative.

The Quekett is, as I have said before, a society of students,
neither desiring to rival or reflect the Microscopical, but to supple-
ment it. Looking over the papers, and listening to its meetings, it
does not seem quite to possess the special character it might be
desirable to impress on it. Many of the papers have quite sufficient
integral merit to have been read at any society, but are not
characteristic of ours. They touch on the usual topics in the usual
manner. Of real students' papers there are very few, and I would
appeal urgently to students for more.

Perhaps microscopical science, at present, is itself in some de-
gree chargeable as a cause for this state of things. The modern
tendency is rather to subordinate the ends to the means. The
actual work done is decidedly below all proportion to either the
quantity or quality of admirable instruments turned out by our best
makers. But do we not, in testing and proving their admirable
qualities, rather addict ourselves to those branches of investigation
which test the power of the instrument more than the intelligence
of the observer ? Reaumur, or Leuwenhoek, or Swammerdam, or
Tremblay, had nothing to compare with our ordinary commercial
Birmingham instruments, much less with our best artists' work, but
has our society collectively yet produced a tithe of the labours of
one of these great men ? As bearing on this, students cannot be
too frequently reminded that facility of labouring with the simple
microscope must precede all valuable study. The young
microscopist is too apt to undervalue the resources of this instru-
ment. Again, few remember how important, how essential, are
those two powers, to dissect and to draw ; nothing can replace or
compensate for them, and yet how many who profess and call them-
selves microscopists can do neither.

Every naturalist knows the immense amount of detail which the
study of any given organism reveals. Lyonnet's marvellous mono-
gram on the caterpillar of the goat moth is a case in point ; but
few microscopists in the Quekett Club addict themselves to one
subject of study — not that it is therefore to be counselled that no
illustrative demonstrations should be taken. Nature is a whole ;
every part has relation to every other ; but the microscopical
student will do well to adopt a line of study, a single branch of in-
quiry, and let that be the thread on which to string his subsidiary

106 THE PRESIDENT'S ADDRESS.

matter. For example, to study the nervous system first in a single
insect through, all its metamorphoses, paying special attention to
the nerves serving special organs, antenna, secreting glands, strings,
ovipositors, then following the modifications into allied genera, and
subsequently tracing them into other orders. Such an inquiry
would occupy a very wide area and produce valuable results, and
the student feeling their fertility and interdependency, would be
stimulated to continue to mount and preserve his dissections, to
register his observations, and thus accumulate knowledge. The
amount of valuable information lost for want of systematic registra-
tion is surprising ; no man will record isolated facts without en-
chainement, and if he did, he could make no use of them.

Few microscopists seem to be aware of the unreclaimed territory
spread out for their investigation, in the comparative anatomy of
special organs, whether of plants or animals. The fertilisation of
cryptogams has been a good deal discussed ; but how their repro-
ductive organs are related, and how and why they have been modi-
fied, very little. Every rnicroscopist knows the general character
of cellular tissue, but how many know the comparative character
of the tissue in different plants, and mode of modification ?

Again, the phenomena of fermentation, so ably treated by Pas-
teur, in a chemical point of view, offer a grand field for microscopic
investigation. The relation of this subject to health and disease
will bear a vast deal more of discussion than has hitherto been ac-
corded to it. The mysterious relations of life to matter may receive
some elucidation from carefully conducted microscopic research. A
more noble field for the exercise of the human intellect can scarcely
be imagined.

And this gives occasion to suggest some points for rendering our
instrumental strength more available for research, by means of col-
laboration — a principle of action more frequently in force abroad
than at home.

There are many microscopists with means at their disposal, and
magnificent instruments, who have no leisure for collection, nor
skill in drawing and dissection ; there are young and active members
of the Quekett with leisure and skill, and small means. Now, let
us suppose a member fortunately blessed with a complete instru-
mental outfit, associating himself with two or three active young
men, one a good dissecter, a second a skilful draughtsman, and a
third an industrious collector, and imagine these addressing their
talents to the cultivation of one of the lines of research above

THE PRESIDENT'S ADDRESS. 107

pointed out, how valuable to us would be their combined labours,
and what a characteristic volume would our transactions become.

There is another field for labour, comparatively uncultivated,
available for those who may have neither of the enumerated quali-
fications — the abstraction and reduction of the vast mass of British
and foreign literature bearing on our subject-matter. Before a
student begins a line of inquiry, he wants to know what has been
done ; for example — who has investigated the functions and struc-
ture of the antennas of insects ? That inquiry alone would occupy
weeks, and would lead him through an enormous mass of irrelevant
matter, scattered through general and special treatises, monographs,
reports, and transactions of innumerable societies. The Quekett
could well spare an occasional evening to hear the summarised re-
sults of an examination, pursued through these sources, into any
branch of sj)ecial study ; and the historical enumeration of previous
labours often supplies a valuable stimulus to further investigation.

Again, permit me to urge on our younger members the impor-
tance of mastering the principles on which our instrument is con-
structed, for, believe me (although I am well aware we have able
and skilful niicroscopists who do not possess this knowledge), it
will tend much to a true interpretation of what the microscope dis-
closes if we have some knowledge of the optical principles on
which it acts. I question if there are many in this room, skilful
as they may be in the manipulations of the instrument, who have
any clear conception of the principles on which the achromatism is
produced, and fewer still who know anything whatever of the laws
regulating the phenomena of polarisation. The study of optics,
both physical and geometrical, is well worthy the attention of
every microscopist, for unless he has mastered these, he is de-
pendent in a great degree upon rules and methods, to him
more or less empirical, for the use of his instrument, and
the interpretation of what it presents to his eye. Many
a fallacy which now passes unheeded might be detected if he knew
the principles upon which the representation of the object was
brought to his view. What insight might be obtained into the
internal and molecular structure of objects, if the observer knew
thoroughly the properties of polarized light, instead of relying
simply on certain empirical rules, and unable to interpret the
exceptions. The rules alone might lead him astray, whilst a power
of discriminating the exceptions, which a knowledge of principles
would give him, might carry him on to further researches and

108 THE PRESIDENT'S ADDRESS.

ultimate discovery. It is singular that, while astronomical science
has kept ahead of her instruments, and has always been pushing
forward the opticians to meet the wants of the astronomer, in
microscopic science the contrary would seem to be the case. Our
opticians here have gone ahead of the observers, and I think it may
fairly be said that microscopic science has not advanced in discovery
proportionately to the means which optical science has placed at its
command. How far this is attributable to the neglect of optical
science on the part of our observers may be disputed, but I cannot
help thinking it may have something to do with it. While I am
advocating the study of optics, let me not be supposed to confine
my suggestions to optics alone ; indeed, they cannot be studied with
any degree of profit unless in connection with other branches of
physics. Every day is bringing each branch of science more and
more into relation with the others ; in studying one, the principles
on which it is based are found applicable, more or less, to all.
And here let me say a word on behalf of mathematics as an adjunct
to these studies. It is the fashion now-a-days to throw reproaches
on the study of mathematics as useless in the study of physics, but, I
venture to think, very undeservedly ; for although there has been
hitherto in our universities a neglect of experimental physics, and too
exclusive a teaching of natural philosojDhy by means of mathematics
only, I hold that the union of the two is essential for the thorough
investigation of physical science. Let the student get a true con-
ception of the principles which experiment will give him, and he
will find, in mathematical language and methods, a means for ex-
pression of thought, which will more readily enable him to pursue
his investigations than if left to unaided reasoning alone.

Our instruments are marvels of optical power. We have gone on
from the l-4th to the l-8th, the l-8th to the l-12th, from l-12th to
a l-25th, and even to a l-50th. The opticians have placed at our com-
mand powerful means of research, and what account can we give of
the talent committed to our charge ? I fear the answer is not one of
which we can be proud. Look at the means in the hands of our
early microscopists, and note what they did, and how much they
accomplished with far inferior means and appliances. I fear we
are too apt to pride ourselves as being the possessors of superior
instruments ; each man pits his microscope in rivalry against his
neighbour's, and rejoices that he can beat him in the resolution of
Nobert's test lines. There, unfortunately, the rivalry too frequently
ends. The difficulty in this matter no doubt is, that our young men,

THE PRESIDENT'S ADDRESS. 109

ardent and energetic as they are, rarely have had that early training
in the elements of science which fits them for taking up any special
line of research. The young microscopist finds himself at starting-
confronted by difficulties in the pursuit of any special investigation,
frequently arising from the want of that mere elementary know-
ledge in science, which might readily have been imparted to him at
school, but which, alas ! has been totally neglected. He has the
tools, the tools of marvellous power, and he is incapable of turn-
ing them to account, because he knows nothing whatever of
the elements of any science in which he ardently desires to com-
mence a research, and finds that he must pass through the drudgery
of these elements ere he can start on his career of investigation.
He is thus disheartened, and his instrument too often remains in
his hands, simply a splendid toy. Happily these times are passing
away — the days of exclusive classical teaching are numbered.
Science is gradually making its way into our schools, and I trust
that the coming generation will go forth into the world better pre-
pared for promoting the progress of science, and its application to
the material interests of mankind. Improved education lies at
the root of all our progress. This, however, is not the place to
enter on the educational question, though, necessarily, associations
like ours feel a deep interest in it, and are largely affected by it in
their influence for good. While, however, I have been pointing
out what, in my opinion, the Quekett may do more than it already
has done, I wish clearly to be understood as in no way expressing a
censure on its proceedings ; on the contrary, it has already done
much if it has only fostered a taste for microscopic research, and
cheered on the student to pursue a career which, unaided, would
have led to nothing ; and if any words which I have dropped this
evening can in any way promote its usefulness, my object has been
attained. The club was prosperous when I had the honour of being
elected to preside over it, and it is a source of pleasure and pride
to me that, thanks to the able assistance of my colleagues in the
Council, to whom all the merit is due, I hand it over to my
successor in a no less efficient condition than it was entrusted to
me. Gentlemen, I thank you for the kindness with which I have
at all times been treated when I have come among you, and for the
very friendly assistance which every one has so fully given me in
my year of office. Wishing the club a prosperous and successful
career, I take my leave.

Journ. Q. M. C. No. 12. i

110

The Pencil-tail. (Polyxenus Lagurus.)

By S. J. McIntire, F.E.M.S.

Pencil-tails inhabit the bark of the willow, the elm, and the
apple-tree. Occasionally they may be seen wandering in a solitary
manner, but generally they are to be found in colonies numbering
four or five, and very often as many as thirty. When the colony is
this size there is generally in its immediate neighbourhood a web
which may be spun by the Polyxeni, but it may be the deserted
home of some spicier. Although there is strong suspicion that the
former suggestion is probable, it is by no means proved, and I would
rather wait till the pencil-tails have been detected in the act of
spinning it, before endorsing the strongly asserted opinions of a
certain friend of mine on this point.

I have kept them alive for various periods of time during the
past five or six years, and they have proved a source of much plea-
sure to myself and others. Their beauty is remarkable, but they do
not display much intelligence. At various times from the middle
of April to July, I have been gratified by finding they had
deposited eggs, but I am sorry to say that I was not successful in
the attempt to hatch and rear the young. The eggs have always
been in small groups of about one dozen, white, oval, and imbedded
in a quantity of hair, which is easily recognized as having been ob-
tained from the creature's tail. The single hairs are most care-
fully interlaced with each other and round the eggs, and the whole
forms a beautiful object not unlike a miniature bird's-nest contain-
ing eggs. Dr. Gray first called my attention to the depositing of
eggs in a cell I gave him some two years since, and a day or two
afterwards my own specimens fabricated similar nests. Our
secretary, Mr. White, has the satisfaction of being 'the first to wit-
ness the hatching out of the young ; this happened to him a few
days ago, and he kindly permits me to quote portions of his letter
intimating the success of his experiments.

"The number of eggs seems to be irregular, about nine being

S. J. m'intire on the pencil-tail. Ill

laid in one nest, four in another, and five or six in another ; for
some few days or so before they are hatched the embryo can be
seen through the walls of the egg, and the eyes are reddish, five in
number, and arranged in a slight double curve. When born they
have three pairs of legs, they are almost white when they first
emerge, but soon become tinted a pale drabbish-yellow. The
period of incubation seems to be about six weeks, because my first
eggs, laid on June 1st, hatched yesterday ; some laid a day after
are hatching to-day, while some eggs laid later are only showing
signs of hatching." (12th July.)

I once thought February was the best time for collecting
Polyxeni, but I have since ascertained that they may be obtained
in various stages all through the year. These stages are indicated
by the number of feet which the pencil-tails possess. It would
appear that three pairs of feet is the minimum number, and 13 pairs
the maximum. This latter number indicates the adult condition which
is attained by successive moultings. I have had at one time in the
same cell individuals possessing four, six, eight, ten, and thirteen
pairs of feet respectively. The cast skins, representing the pro-
gressive development of the Polyxeni, are to be found in abundance
in the neighbourhood of their home, and, if carefully collected and
mounted, form interesting and beautiful microscopic objects. Ex-
cepting in the number of segments, which is variable for the reasons
above stated, there is no difference between the exterior ornamenta-
tion of one pencil-tail and that of another ; they are all equally
beautiful.*

The dorsal aspect exhibits curious scales, each of which is a
study in itself, in transverse double rows. In the adult condition
there are ten of these rows, and the sides of nine of the segments
which are thus ornamented by these appendages are still further
graced by bushy tufts of erect scales of somewhat different, though
analogous structure. I think also, that the dorsal rows of scales
are erectile at the will of their owner.

Viewed with the dorsal aspect next the eye, no feet are visible
the little pencil-tail glides along the field of view while the observer
wonders how it makes progress, and is charmed with the harmoni-
ous blending of colour, especially if it be on a piece of its native
bark, stained with fungi-spores of various colours. The skin is

* Especially beautiful are they for some six hours or so after a moult.

i 2

112 S. J. McINTIRE ON THE PENCIL-TAIL.

yellowish-grey, with three brown bands extending from head to
tail ; the scales are of leaden hue, and curiously sculptured ; while
the double bunch of hairs at the caudal extremity glistens like
frosted silver or driven snow.*

The head is abundantly furnished with fantastic rows of erect
scales, among which the antennae may be seen rapidly vibrating,
and occasionally the strange-looking little groups of simple eyes,
situated at the sides of the head, appear for an instant and then are
• obscured. Bye-and-bye the pencil-tail, which seems to love dark-
ness rather than light, exposes its ventral surface to the bright
beam of light we have cast upon it, by climbing upon the cover of
the cell, and the aspect now is quite as bizarre as that I have
endeavoured most ineffectually to describe. Such a regular array
of many-jointed feet ending in sharp claws, all in motion ; such a
curious mouth ; the integument of the belly folding into rhombs
and triangles as it moves ; but there ! I know my listeners will
endeavour to see this little creature for themselves, so I need not
expatiate further in this fragmentary educational sketch.

Should any one be induced to study the anatomy beyond the
points I bring forward now, and let us hear the results of his
observations, we shall all be the better for it, and my object will be
attained. In order to assist such enquirers, I have searched for
and collected -the following notes respecting the Myriapoda : —

Until 1867 only two orders were recognised in the group of
Myriapods — viz., the Chilopods and the Diplopods. The former
are all " active and carnivorous," and the latter " sluggish vege-
tarians." So says Sir John Lubbock in his paper in the Linnean
Transactions, on Pauropus, a creature possessing so much in
common with each of these orders, and yet so much distinctive,
that its claim to be considered as the representative of a third order
of Myriapods is now, I think, undisputed. I quote a few of his
remarks : —

" Chilopods. — Antennae 14-jointed at least ; one pair of legs
modified into powerful jaw-feet ; generative organs opening at the
posterior extremity of the body ; legs in single pairs.

" Diplopods. — Antennae with not more than seven segments ; no
jaw-feet ; apertures of the generative organs in the anterior part of
the body ; legs, after the first six, arranged in double pairs."

* These hairs are figured in Carpenter as ' ' Hair of Myriapod."

S. J. McINTIRE ON THE PENCIL-TAIL. 113

Examples of the ferocious Chilopoda are to be found in the
various descriptions of centipedes ; and of the vegetarian Diplo-
poda in the various " pill-millepedes " (or, as some call tbem,
" wood-lice "), the Julidse (or wire-worms of the farmer), and our
little friend Polyxenus.

In common with the whole group, the Polyxenus breathes by
means of an extensive tracheal system. Its eyes are, I believe,
ten — in two groups of five in each. There are, however, on each
side of the head two objects, whose character I have not satisfac-
torily determined ; if they are eyes, the total number is fourteen.
The antennas are, I believe, 8 -jointed, although authorities declare
seven segments in these organs is the maximum number existing in
any of the Diplopods. It would appear that the Polyxenus is one
of the connecting links between the Myriapocla and the Annelids ;
its nearest congener in that group being Nereis, one of the marine
worms.

These points, and many more bearing upon the subject, which I
need not dilate upon, are detailed in the paper I have alluded to
(Transactions of Linnean Society, Vol. xxvi.), and I recommend
those interested to read it.*

A casual allusion is made in " Wood's Natural History" (Rout-
ledge) to Polyxenus. He says (Vol. iii., p. 696) that "it is found
under the bark of trees, in clefts of walls, and in moss." Dr. Gray
and myself found a couple under a stone at the foot of a tree near
Mickleham on June 24th of this year, but this was quite an excep-
tional case in my experience. I never before obtained any else-
where than on willow, apple, and elm trees, and I therefore think
the two specimens I allude to must have been, like so many mem-
bers of the Quekett Club on that day, out for an excursion when
we caught them. Strangely enough, too, under the same stone
there was a larva of Tiresias Serra, a well-known friend to some
of our members, owing to the ventilation of the " Hair of Dermestes"
question. I have often noticed the association of these two crea-
tures, and guessed the reason why. The Tiresias larva is carni-
vorous, and the Polyxenus vegetarian. Does the Tiresias feed
upon Polyxeni ? I must leave that question for the solution of
enquiring observers. In " Science Gossip" (Vol. i. p. 230) a figure

* In another paper, by the same author, " On the generative organs and
formation of the egg of the Ammlosa " (Philosophical Transactions, 1861, page
595), there is avast amount of information also.

114 s. J. m'intire on the pencil-tail.

of each, accompanying my short paper, will be found. The associa-
tion of the two, even then (1864-5), often attracted my attention.

Dr. Gray has since told me the further adventures of these three
captives. They were all put into a cell together, and for a time all
went well, but within the last few days the Tiresias larva has cast
his skin and come out quite smart, whilst one of the pencil-tails
has died. Not only died, however, for every vestige of him has
disappeared. I need hardly say that strong suspicion of foul play
rests on the character of that Tiresias larva in this matter.

The compendium of Generic Distinctions at the end of " Wood's
Natural History" (Vol. iii.) contains much information respecting
the Myriapoda, put in a convenient form for study.

There is also some information, very good, but at the same time
very scanty, to be obtained in the " Micrographia Dictionary,"
under the head " Myriapoda."

I think I have now put before you as briefly as I could the most
valuable of the information I have been able to obtain, and it only
remains to me, after thanking Dr. Gray and Mr. T. C. White for
many hints, and Mr. Ward and Mr. Blatch for specimens which
they have kindly furnished me with, to indicate the method of
capture and keeping of the pencil-tails which has been found most
successful. Having discovered the objects of our search in the
localities I have pointed out, or in other new ones, a camel's hair
pencil and a test tube are indispensable to effect the removal of the
pencil-tails from their homes uninjured.

Then, or as soon afterwards as possible, our tubes must be emptied
into cork cells such as I have described on a former occasion. It
will be well to introduce as food a small fragment of the bark also,
and if it is kept damp they will often be seen feeding upon it. So,
too, will they feed upon the blotting paper of the cell, and on one
occasion a healthy colony I had succeeded in capturing burrowed
their way through it and escaped, to die, I fear.

Plate XII. illustrates this Paper, and contains a magnified view of the
wider-side of the insect, the hairs and scales, and a cluster of eggs.

115

Chislehurst Excursion, May 28, 1870.

In a search among the nettles in the vicinity of the Kailway station
I obtained a fly, to the abdomen of which were attached three
parasites. The fly was a small Psychoda, one of those curious
small flies with broad deflexed hairy wings, and long antennaa, com-
posed of globular verticillated joints, often found on windows, and
said to reside, while in the larva state, in dung ; and the parasites
were acari, nearly allied to the parasites common on the humble
bee — a species of Gamasus in fact. Though the fly, when put into
a collecting tube, ran about actively, I doubt not it was much in-
convenienced by its triple burden (which to the naked eye appeared
as if the fly's abdomen were red), for on my arrival at home, I
found it had succumbed, though the parasites still remained in
position. I, therefore, shook it out of the tube, and dropped some
benzine upon it immediately it had fallen upon the glass-slip. This
of course killed the parasites ere they had time to escape, and was
preliminary to further applications of benzine and balsam. The
final result was moderately successful : the fly and its parasites
form a slide in my cabinet.

The Curculionidse obtained were not numerous, it being rather
early for them, yet such as we did find were of great beauty. As
about 400 species are known to be inhabitants of this country, it is
a matter of difficulty to be certain as to the names. Westwood,
however, says that "the Polydrusi and Phyllobii" are not less
beautiful than the Diamond Beetles of the Tropics, though of
smaller size than they; and this is all the authority I have for
considering the brilliant green or red beetles found on this occasion
to belong to this genera. The same authority says that the larvae
of these beetles are more or less like the fleshy grub which we often
find in the inside of nuts, and that they are vegetable feeders in all
stages of their existence. I believe all that we found on this oc-
casion feed on herbaceous plants, especially the nettle, and the foli-
age or soft twigs of the oak and the beech trees.

116

CHISELHURST EXCURSION.

A little earlier in the season I noticed, on Wimbledon Common,
a small species in the perfect condition feeding on the blossoms of
the furze, which were punctured with minute holes just large
enough to introduce a pin. The brilliantly-coloured species of Cur-
culionida3 are always best mounted in balsam, but the more homely-
coloured ones (those found on the nettles all through the summer,
which claim notice rather from their curious shapes than their
scaly coating) are perhaps best mounted dry.

In collecting these beetles one soon observes their habit, as
soon as they are alarmed, of loosening their hold of the stem or
leaf upon which they were walking, and dropping to earth. A
knowledge of this fact enables the collector to circumvent them in
their artifice to escape from danger, by placing his trap, consisting
of, it may be, an umbrella, or, as happened on this occasion an
obliging friend, underneath the branch, which was then shaken ; of
course the beetles and various other insects fell on to his shoulders
and back, whence ingenious Queketters, never at their wits' ends,
transferred them to their bottles and boxes.

Numerous small flies were obtained, respecting which I am un-
able to offer any observations. I may, perhaps, however, be per-
mitted to mention a plan of preparation of such tiny insects, which
has lately found favour with me. It is to kill the insects in benzine,
and let them soak there until the spirit has thoroughly permeated
them. Then mount them in cold fluid balsam, and wait patiently
for it to set. The drawbacks of the process are that oftentimes
the less are not in desirable position, and there is much opacity ;
but the advantages, which to my mind counterbalances these, are
that the specimens are not damaged to the extent that often is the
case by the use of liquor potassac ; and under reflected light the
natural colours are not hidden or changed.

Of the Thysanura, numerous specimens of the genus Smynthurus
were obtained ; some of them were of purple colour on the dorsal
surface, and others yellow. These latter were probably Smynthurus
Aureus. They are very curious little creatures ; so curious, in-
deed, that were they better known they would be much sought
after. As well as the surface of stagnant pools, they inhabit grass,
and nettle banks, and considerable numbers of them fall to the
bottom of the net which is used to sweep these localities. From
thence they must be swept into collecting tubes with a light jerk of
a camel's hair pencil if we desire to capture them.

CHISELHURST EXCURSION. 117

Although relatives of the scale-bearing podurte, their affinity
with them is not at first sight apparent. Their bodies are of oval
shape, and their heads, which bear long four-jointed antennae, are
very large in proportion. The eyes are situated just behind the
antennae, in two groups of eight in each. They possess a long
forked caudal appendage or springer, but one of their most curious
features is the ventcal tube, whence they are able to protrude two
long filaments or tentacles to an extraordinary distance. In this
manner they appear to be able to reach the greater portion of the
surface of their bodies, and it may be, to lubricate it freely by means
of them. Nicole t, quoted by Sir John Lubbock, says of these ten-
tacles that they are gifted with a retractile movement exactly like
that of the tentacular eyes of the slugs. A short time ago a friend
of mine in the country was looking at a number of Srnynthuridae he
had captured. Presently one which was presenting its dorsal
aspect to the microscope, suddenly extended these filaments, and
wriggled them round its shoulders, and then as suddenly withdrew
them. The surprised observer was not prepared for such a per-
formance, and immediately wrote me a long letter for an explana-
tion, which fortunately Sir John Lubbock's papers in the Linnean
Society's Transactions enabled me to give him. The first time I
saw the performance myself I was equally astonished.

S. J. McIntire.

MR. SUFFOLK'S LECTURES.

" Microscopic Manipulation, being the subject matter of a course of Lectures
delivered before the Quekett Microscopical Club, January to April, 1869. by
W. T. Suffolk, F.R.M.S.,"*will explain itself what this volume contains. Mr.
Suffolk's practical demonstrations on " Manipulation," given for two or
three successive winters to members of the Club, are so well and gratefully
remembered by those who availed themselves of the privilege of attending
them, that they will welcome the present volume, and recognise in it the face
of an old friend. The seven chapters of the book are devoted to Construc-
tion of Microscope — Mechanical Processes — Mounting Objects Dry and in
Balsam — Mounting Objects in Fluid — Illuminating Apparatus — Polarised
Light — and Drawing and Micrometry. These are illustrated with forty-nine
engravings and seven lithographs. The volume is neatly got up, and we
presume that only this announcement is needed to induce every member at
once to purchase a copy for himself, not only for its own intrinsic value, but
also in recognition of Mr. Suffolk's valuable gratuitous services for the
benefit of the Club.

* London. Henry Gillman, Boy Court, Ludgate Hill.

118

PROCEEDINGS

Mr. Archer.

June 24th, 1870 — Chairman, Dr. R. Braithwaite, F.L.S., V.P.

The following donations were announced : —

" Science Gossip" ... from the Publisher.

" Land and Water " (weekly) the Editor.

"The American Naturalist" in Exchange.

" Transactions and Proceedings of the Edinburgh) . v

Botanical Society " f

Dr. Carpenter's <c Principles of Human Physiology" Mr. John Michels.

Suffolk's " Microscopical Manipulation " The Author.

50 Slides Mr. M. C. Cooke.

Also, for distribution amongst the members, a

number of Packets of Washings from the I

Lambeth Whiteing Works, containing Spicula,

Foraminifera, &c

Copies of " Chambre noir et le Microscope Photo- ]

micrographie Practique," by Monsieur Jules r

vJ LI ill Li in ••• •*• ••• »«» ••• /

' The thanks of the Club were voted to the donors.

The following gentlemen were balloted for and duly elected members of the
Club :— Dr. Lionel S. Beale, F.R.S., &c, Mr. A. E. Birch, Mr. W. J. Brown,
Mr. Samuel J. Hawkins, Dr. Henry G. Knaggs, F.L.S., Mr. Wm. N. Locking-
ton, Mr. F. W. H. Preston, Mr. William Smith, Mr. Ernest Swaine.

Mr. M. C. Cooke read a communication from Mr. F. Kitton, of Norwich,
"On the Diatoms of the Morz Deposit of Jutland."

The thanks of the meeting were returned to Mr. Kitton for his paper.

Mr.M. C. Cooke also read an extract from the letter of a New York corres-
pondent, stating that at a recent meeting there had been exhibited there a
specimen of Pleurosigma angulatum, magnified 98,000 diameters, with plenty of
light and clear definition. The extent of this amplification might be judged
from the fact that the diameter of the field just included 4 J spherules, and 15 of
them covered the circular field of view. It was the finest exhibition of the kind
which the writer had yet seen. The exhibitor on the occasion was Mr. Dickin-
son ; the object-glass l-30th inch, by Wales, with No. 13 eye-piece, excellent
illumination being obtained by one of Abram's condensers.

The Chairman said that a proposition had been made by Mr. Ross, which he
had been requested to communicate to the meeting. It was that at the ap-

119

proaching anniversary meeting every member should make some present, no
matter how small, to the Club. Mr. Koss would himself be happy to make a
present of some books, which he had looked out for the purpose. The Chair-
man expressed his own approval of the proposal, and cordially recommended it
to the consideration of the members.

The Secretary very highly approved of the suggestion of Mr. Koss. No doubt
during the year every member had been working at some special object, and
had prepared slides of it, which would make most acceptable and valuable addi-
tions to the Cabinet. One gentleman, Mr. Michels, a newly-elected member,
had that evening presented to the library a copy of Dr. Carpenter's " Principles
of Human Physiology," intimating that he did not know whether it was the
kind of book that was wanted. Now no books could be more acceptable than
works on physiology, the study of which could not be properly carried on with-
out the constant use of the misroscope. Members were strongly recommended
to give attention to the interesting subject of cell structure, using the am-
moniacal solution of carmine for bringing out its beauties whilst under examina-
tion.

The Chairman announced that in accordance with the bye-laws all the officers
of the Club to be elected at the ensuing annual meeting must be nominated at
the present meeting. There were four vacancies on the Committee, caused by
the retirement by rotation of Messrs. Arnold, Burr, Gay, and Slade, who were,
however, eligible for re-election. The President and four Yice-Presidents had
also to be elected. For the office of President, he had great pleasure in being
able to announce that Dr. Lionel Beale, F.R.S., had kindly consented to allow
himself to be nominated, and had promised, if elected, to attend and take the
chair at the meetings as frequently as possible.
This announcement was received with applause.

The Chairman then invited members pi^esent to nominate gentlemen to fill
the four vacancies as Vice-Presidents, intimating that six could be placed on the
list in nomination, from which number four would be elected by ballot at
the Annual Meeting.

The following gentlemen were then nominated as Yice-Presidents: —
Mr. A. E. Durham, proposed by Mr. Bywater, seconded by Dr. Matthews.
Mr. Henry Lee, ,, Mr. M. C. Cooke, ,, Mr. Hay ward.

Dr. Braithwaite, ,, Mr. Jaques, ,, Mr. Arnold.

Mr. Arnold, ,, Dr. Gray, ,, Dr. Matthews.

Mr. P. Le Neve Foster, ,, Dr. Matthews, „ Mr. Bockett.

Mr. Gay, ,, Mr. White, ,, Mr. Hailes.

The Chairman then intimated that nominations of gentlemen to fill four
vacancies upon the Committee had next to be made. In this case also six names
could be placed upon the balloting papers, from which the selection would be
made.

The following gentlemen were then nominated as members of Committee :

Mr. Allbon, proposed by Mr. Curties, seconded by Mr. Marks.
Mr. Golding, „ Mr. Mclntire „ Mr. Hailes.

Mr. C.F.White „ Mr. Euffle, „ Mr. T.C.White

Mr - Lo y> „ Dr. Gray, „ Mr. Eeeves.

Mr. Burr, ,, Mr. Bywater, „ Mr. M. C. Cooke.

Mr. Bywater, „ Mr. Johnson, ,, Mr. Hailes.

Mr. Slade, ,, Mr. Garnham, „ Mr. Quick.

Mr. Marks, ,, Dr. Matthews, ,, Mr. Hailes.

120

Eight gentlemen having thus been proposed, the Chairman proceeded to de-
cide by show of hands which two names should be removed from the list, and
Messrs. Marks and Slade being declared in the minority, their names were accord-
ingly struck out.

The following recommendations by the Committee were also announced by
the Chairman — That Mr. Robert Hardwicke be appointed as Treasurer for the
ensuing year, Mr. T. C. White as Hon. Secretary, and Mr. M. C. Cooke as Hon.
Secretary for Foreign Correspondence.

The election of Auditors of the accounts for the year then took place, and Mr.
W. T. Suffolk having been appointed Auditor on behalf of the Committee, the
members were requested by the Chairman to elect an auditor on behalf of them-
selves. Mr. Oxley was thereupon proposed by Mr. Hainworth, seconded by Mr.
Jaques, and duly elected by show of hands.

Dr. Matthews called the attention of the meeting to a further improvement in
his turn-table. When he described his arrangement for holding the slide at the
last meeting, he thought that he had arrived at the neplus ultra in turn-tables ;
there was, however, no such thing as perfection. Since that meeting Mr.
Edward Hislop bad discovered that we might dispense with the wedge entirely,
by making the jaws of hard brass, with their surfaces curved. Enough spring
was thus obtained to hold a slide firmly, and this alteration really seemed to
have reduced the instrument to its very simplest form.

The Secretary announced that Mr. Golding had prepared a number of sections
of rush for distribution amongst such members as wished to have them and were
provided with bottles. The meetings and field excursions of the ensuing month
were also announced, and it was stated that at the next ordinary meeting Mr.
S. J. Mclntire would read a paper " On the Collections at one of the Excur-
sions of the Club."

The proceedings terminated with the usual conversazione, at which the fol-
lowing objects were exhibited : —

Batrachospermum by Mr. Golding.

Section of Tooth of Pike (Polarized) by Mr. Oxley.

Nest of Polyxenus Lagurus, made of its own hair... by Mr. S. J.McIntire.

ANNUAL MEETING.

July 22nd, 1870.— P. Le Neve Foster, Esq., M.A.,

President.

The Secretary read the reports of the Committee, the Treasurer, and the
Librarian.

The President moved, "That the reports now read be received and
adopted."

Dr. R. Braithwaite seconded the motion, which was carried unanimously.

Mr. Lampray observed that there was a striking disproportion between the
number of members and the amount of subscriptions received, and he inquired
if this were due the number of subscriptions in arrear ?

The Treasurer replied that such was the case ; he had himself used due dili-
gence to get the amounts paid, but as the subscription was too small to employ

121

a paid collector, the matter had, for the most part, to be left to the members
themselves to pay promptly.

Mr. Lampray said that the same thing had occurred to him at the last annual
meeting, but it appeared there were a larger number of arrears this year. He
thought this ought not to be so.

The Treasurer remarked that if some member would kindly make a proposi-
tion to bring defaulters to book, he himself at all events would be very glad.

Mr. Lampray inquired if those members, whose subscriptions were in arrear,
continued to be supplied with the journal.

The Secretary informed Mr. Lampray that they had lately got rid of a great
many defaulters ; both he and the Treasurer had, in accordance with the bye-
law, made written applications for payment, and no responses being received,
the names were struck off the list.

The President, previous to his retirement from the chair, read an address,
which was listened to with marked attention, and closed amidst loud and pro-
longed applause.

Mr. M. G. Cooke said he rose to propose a resolution to the club which, after
the admirable address they had just heard, needed no remark from him. He
rose to propose the thanks of the club to their worthy President for his ser-
vices during his year of office, and for his admirable address that evening.

Dr. R. Braithwaite seconded the motion, which, on being put to the meeting
by Mr. M. C. Cooke, was carried by acclamation.

The President returned his thanks to the club for the kind manner in which
the vote of thanks had been proposed and received ; he was only sorry that he
had not been able to attend the meetings more often ; he had, however, done so
as often as was possible, and it had been a source of great pleasure to him to
do so.

Mr. W. J. Brown and Mr. Quick having been appointed scrutineers, pro-
ceeded to distribute and collect the balloting papers for the election of officers
for the ensuing year; meanwhile,

Mr. S. J. Mclntire read a paper " On the Pencil Tail (Polyxenus Lagurus),"
which he illustrated by a series of pencil drawings.

Mr. T. C White said that he had been named in the paper as having been
successful in hatching some Polyxeni. Mr. Mclntire said some time ago that
the eggs laid in his cells had dried up ; thinking, therefore, that more moisture
might be necessary, he had himself kept his own cells constantly damp, and also
placed them in the sun. Some remarks which he had read as to the influence
of light upon germination, led him to do this, so he kept the damp cell contain-
ing the eggs upon the window sill in the sun, and they hatched there in six
weeks. When first hatched the young had only three pairs of legs, and it would
be interesting to note how many additional pairs were added at each successive
moult.

A cordial vote of thanks was then proposed by the Chairman to Mr. Mclntire
for his paper, and carried unanimously.

Mr. Burgess intimated to the meeting that he had brought with him for dis-
tribution a quantity of acari from Mexico; he did not know whether they might
prove to be new forms. A friend of his (a member of the club) had in his ware-
house a large number of bags of cochineal, and observing that not only the bags
but also the floor of the warehouse had become covered with a large quantity
of white dust, he took some home, and on examination, found it to consist
of insects, most of which were covered with hairs, and there appeared to be

122

several varieties of them. He had with him a supply of these insects, and
should be most happy to distribute them amongst such members as were in-
terested about them.

Mr. W. H. Golding made some suggestions to the meeting relative to the
desirability of giving the members free access to the library and cabinets at all
the meetings of the club, and to the arrangements necessary for so doing,
and after a few observations upon the subject from Mr. M. C. Cooke and the
President, the matter was considered as one to be dealt with by the Committee,
and it was referred to them as a recommendation.

The result of the ballot having been handed in by the scrutineers, the fol-
lowing gentlemen were declared by the President to be duly elected: —

As President Dr. Lionel S. Beale, F.R.S., &c.

f Dr. R. Braithwaite, F.L.S., &c.

. .Jk t, . , . J Arthur E. Durham, F.L.S., &c.

As Vice-Presidents < -^ T _ T „ .

Henry Lee, F.L S., &c

^ P. Le Neve Foster, M.A.
f Mr. Allbon, F.R.M.S.

. , r . „ „ J Mr. T. W. Burr, F.R.A.S., &c.

As Members of Committee -< K m w ,, , r,^,,

j Mr. W. M. By water, F.E.M.S.

^ Mr Charles F. White.

As Treasurer Mr. R. Hardwicke.

As Hon. Secretary Mr. T. C. White.

As Hon. Secretary for Foreign Cor- ) Mjf< M> Q Cqo ^ M A

respondence..... '

The President then formally left the chair, and installed his successor, who
was greeted with considerable applause.

Dr. Lionel S. Beale, on taking his seat, begged leave to thank the mem-
bers of the club very heartily for the honour which they had conferred
upon him in electing him as their President, and expressed the great
pleasure which it would afford him to come amongst them. For the last sixteen
years he had been actively employed in lecturing and otherwise, the conse-
quence of which was that his work had been very much restricted to particular
subjects. In his early days there was no Quekett Club, and as it was his fate
to be early placed in a position of some public importance, it was necessary
that he should concentrate his attention, perhaps even more than Mr. Foster
would have recommended, and the consequence was that he was terribly ignorant
of other subjects. He had listened with the greatest pleasure to Mr. Foster's
address, and could endorse every word of it ; it had also given him great pleasure
to listen to the interesting paper of Mr. Mclntire, the result of which would,
no doubt, be that before long a great many cells of these little Polyxeni
would be in the hands of members, for this was a club of workers, and had
for its founder one of the most earnest workers which science had ever seen.
The following donations to the club were announced : —

"Land and Water" (Weekly) from the Editor.

Science Gossip " the Publisher.

The Monthly Microscopical Journal " the Publisher.

The Popular Science Review " the Publisher.

" The American Naturalist," and the "Proceedings') In exchange for the

of the Birmingham Natui'al History Society " j Journal of the Club.

Eley's " Geology of the Garden " from Mr. Bockett.

"The Microscope Made Easy," 1742 Mr. T. C. White.

it

123

The Tyneside Naturalist's Field Club Transactions Mr. Bywater.

Carpenter's " Vegetable Physiology " Mr. Groves.

" The Microscope," by Dr. Carpenter ... ... Dr. Kamsbotham.

24 Slides Mr. T. 0. White..

12 Slides Mr. Hailes.

6 Slides Mr. Groves.

6 Slides Mr. J. F. Pickard.

6 Slides' , Mr. Walker.

Photograph printed by the Albertype Process ... Mr. Groves.
A new brass Tank Microscope, with 4in.|

objective, in Mahogany Case } ••• Mr. Ross.

The Secretary drew especial attention to the handsome present from Mr.
Ross, and to the liberal manner in which he had followed up his suggestion
made at the previous meeting.

A vote of thanks to the donors was unanimously carried.

The following gentlemen were elected members of the club :— Mr. Joseph F.
Gibson, Mr. F. Johnson, and Mr. Henry King.

The meetings and excursions for the ensuing month were announced by the
Secretary, and the proceedings terminated with a conversazione, at which the
following objects were exhibited : —

Wing of large Yellow Under-wing Moth by Mr. Golding.

Leaf of Loasa Tricolor.. Mr. B. D. Jackson.

Polyxenus Lagurus and hairs of ditto ) « -vr « T M T +"

Fly and 3 parasites i

August 26th, 1870. — Chairman, Professor Lionel S. Beale,

F.R.S., President.

The following donations were announced : —
"The Monthly Microscopical Journal" ...
"Science Gossip"

" Land and Water" (weekly)

" The American Naturalist," August, 1870
"Hogg on the Microscope," 1st Edition...
" Pritchard's Infusoria," 1st Edition

X ollQO.«» •*• • •• ••• ••• •••

50 Slides ... ... ... ... ...

O ollLLL-S ••• ••• «•• •«• ta«

xx ollClcS ••» ••• •«• • •• ■••

36 Slides

}

from the Publisher,
the Publisher,
the Editor.
in Exchange.

Mr. M. C. Cooke.

Mr. L. Bennett.
Mr. M. C. Cooke.
Mr. W. Hainworth, jun.
Mr. Oxley.
Mr. Quick.

The thanks of the Club were returned to the donors.

The following gentlemen were balloted for and duly elected members of the
Club : — Mr. Martin Burgess, Mr. John Carpenter, Mr. Frank Clarkson, Colonel
Hennell, Mr. John Hirst, Robert Henry Houlston, Mr. Samuel Warburton.
Mr. T. C. White read a paper "On papers for the Club."

Mr. M. C. Cooke said he should be glad to hear some discussion upon this
subject ; personally he felt very much obliged to Mr. White for bringing it for-
ward, for he had often tried to stir up members to produce papers, but all the

124

answer he got was " do it yourself." He had done it again and again, and
thought it was now quite time that others should be brought up to the scratch.
If no one answered the paper he should take it for granted that by their silence
members fully agreed with Mr; White's remarks, and that plenty of papers
would be the result.

Mr. Curties communicated to the Club an interesting letter which he had re-
ceived from Mr. Davis, " On the eggs of some parasites found upon birds in the
Zoological Society's Collection." The subject was illustrated by some beauti-
ful drawings, and by a number of photographs presented for distribution amongst
the members.

A vote of thanks to Mr. Curties for his communication was proposed by Mr.
Brain, seconded by Mr. Jacques, and carried unanimously.

Mr. M. C. Cooke read a communication from New York, relative to the ampli-
fication of Pleurosigma angulatum, shown at the Bailey Microscopical Club, as
mentioned at the previous meeting. A photograph of the appearance of the
object on the scale described was exhibited to the meeting, bat in reply to a
question from Dr. Matthews, Mr. Cooke stated that the photograph was not
taken from the object itself, but from a plaster model representing its appearance.

A vote of thanks to Mr. Cooke was unanimously carried.

The Secretary announced that he had received a letter from the Secretary of
the Liverpool Microscopical Society, expressing a desire that at the Soiree in
connection with the forthcoming meetings of the British Association at Liver-
pool the Microscopical Societies should be represented. The Soiree would be
held at St. George's Hall, on Sept. 22nd, and members desirous of exhibiting
on that occasion were requested to make an early intimation to that effect to
Mr. C. H. Sterne.

The following objects were exhibited : —

Seed of Nemesia by Mr. Chas. Collins.

Scales of Hippophse rhamnoides Mr.Conder.

Eggs of Bird Parasites, shown both in the wet 7 ,,- p ,.

and the dry stat es 3

Head of Cysticercus, from the Hare Mr. Groves.

Degeeria domestica (alive) Mr. Oxley.

There were also placed upon the table for distribution amongst the members
a quantity of thin sections of rhinoceros horn and some chrysalids, from Mr.
Archer ; a large number of named specimens of mosses, from Mr. M. C. Cooke j
and a supply of volvox, collected at Woodford, from Mr. W. Hainworth, jun.

Mr. Mclntire observed that the Degeeria exhibited by Mr. Oxley was inter-
esting, as being the third discovery of it in England.

The proceedings then terminated with the usual conversazione.

K. T. Lewis.

125

Manipulation with Canada Balsam.
By D. E. Goddard.

(Read 23rd February, 1866.J

I cannot flatter myself that the remarks I have the honour of
bringing before you contain anything new, or that I shall interest
or instruct the majority of my audience ; nor should I take up the
time of the Association except in the hope that I may assist some
of those who are just commencing the study of microscopical
science.

There is no royal road to learning ; there is nothing, however
trivial, to be accomplished in microscopic manipulation without
patience and perseverance. Very often an instrument is purchased,
and with generous enthusiasm the student dashes into the pursuit
of knowledge, and fancies that he can, by some magic process,
fill his cabinet with his own preparations. With such objects as
require to be mounted dry, he succeeds pretty well ; but when he
comes to manipulate with Canada balsam, he often meets with
failure after failure ; and, perchance, instead of persevering till
success crowns his efforts, he retires from the contest disgusted and
annoyed. Such has been the career of many. I trust it will be
for this Association to extend a helping hand to the beginner to
smooth some of his rugged paths, and enable him to surmount,
with ease and pleasure, those obstacles that others have only passed
with great difficulty and much loss of time.

I have chosen for my subject — " Manipulation with Canada
Balsam."

I purpose noticing —

First. — The medium generally.

Secondly. — Some of the sources of failure, and show how they may
be surmounted.

Thirdly. — The use of chloroform and balsam.

First. — The " Micrographic Dictionary" states that Canada balsam
is the liquid resin obtained by tapping the Pinus balsamea. . It is

Journ. Q. M. C. No. 13. k

126 T>, E. GODDARD ON MANIPULATION WITH CANADA BALSAM

nearly colourless, and more or less viscid. Its boiling point, as far
as I can ascertain by experiment, is about 160 centegrade (320
Fah.) If exposed to the action of the atmosphere, it becomes thick ;
when heated repeatedly, it is rendered brittle, and often passes to
a brown, or straw colour, lighter or darker, according to the degree
of heat to which it has been subjected. If brought into contact
with humid matter, a white cloudiness ensues that will render the
medium useless. It is soluble, to a greater or less extent, in cam-
phine, alcohol, naphtha, benzole, chloroform, eether, and crystal oil.
It is insoluble in water. When I first attempted to prepare my
own slides, I was misled, and met with many failures by following
the adyice contained in some books and papers recommending the
use of "old balsam." My objections to it are, it is too thick to
enter the minute vessels in animal and vegetable structures, and
retains air-bubbles instead of occupying their space. To render it
available, it requires heating more or less ; this, often repeated,
renders it too brittle to trust. It is often discoloured, and some-
times presents a very yellow appearance. It has, however, the
advantage of hardening rapidly ; but, even this, under some cir-
cumstances, is much against its use. The Canada balsam obtained
at opticians will generally answer very well. It should be of such
consistence as will drop readily from a glass rod ; if the drops are
long in falling, it is a proof that the medium is too thick. When
such is the case, it can be made fit for use by the addition of cam-
phine or turpentine. The balsam must be warmed in a water bath
(about 50 cent.) and placed under the exhausted receiver of an air
pmnp. The question may here be asked — What kind of vessel is
the best to keep the medium ?

I object to corked bottles, r because the cork is liable to adhere to
the glass, and small pieces get broken away and fall into the balsam.
A stoppered bottle is also open to criticism. When the balsam soils
the neck, the stopper adheres to it, requiring the aid of heat to
loosen it, and the hardened balsam prevents the total exclusion of
the air, and the medium gets thick.

I prefer using a conical capped gum -pot, the outside neck of
which is ground, the cap thereby fitting like a stopper. If any
balsam falls on it, it may be cleared off without any fear of soiling
the medium.

So much for the general properties of Canada balsam. We will
now notice, in the

D. E. GODDARD ON MANIPULATION WITH CANADA BALSAM. 127

Second place, some of the sources of failure, and how they may-
be overcome.

Foremost among these must be considered those plagues of the
amateur — air-bubbles ; these generally arise from three sources.

1. — Bad, or thick balsam, in which case it must be thinned, as
before mentioned.

2. — Expansion of air contained in cellular tissue, or minute or
intricate vessels. The only method by which such annoyances can
be avoided is by lengthened soaking in camphine or turpentine, and
submitting the preparation to the action of an air pump.

The 3rd source of air-bubbles is the application of too great
heat to the slide, by which the balsam is boiled. The method by
which this can be corrected I shall notice presently.

I may here perhaps caution the student against discarding pre-
parations simply because air-bubbles are present. When the balsam
is in good condition, and no heat, or, at most, very little has been
applied, he will generally find they will disappear in a longer or
shorter period, according to the nature of the specimen mounted.
Many slides that I have thrown aside and forgotten, have, in the
course of a few months, been discovered in my " spoiled box " in a
beautiful state of preservation, every bubble having vanished. The
object to be attained by mounting in balsam is to render the speci-
men transparent, which would otherwise be too opaque for observa-
tion by transmitted light. Most objects for the polariscope require
to be mounted in some medium. Balsam and glycerine are the
favourites for some objects, such as crystals, that would be decom-
posed by balsam, or dissolved by glycerine. Castor oil may be used
with advantage.

I do not wish it to be understood that I advise the use of
Canada balsam for every kind of preparation ; it will be for the
student to find by practise how far it may be made available.

It should be established as an axiom in microscopical manipula-
tion — That the specimen should invariably be soaked for a longer or
shorter period in the medium in which it is to be preserved. Thus,
when balsam is the medium, soak in turpentine, or what is infinitely
better, camphine ; when glycerine is used, let the specimen be
placed in it, and in all cases submitted to the air pump. A cheap
and very effective form of air pump can be obtained from Mr.
Baker, 244, Holborn ; the price is, I think, 18s.

When preparing insects for the microscope, I know it is usual

k 2

128 D. E. GODDARD ON MANIPULATION WITH CANADA BALSAM.

to digest them in solution of potassa, to soften hard structure, so
as to get the object as flat as possible. For some subjects this
mode of treatment may be required, but I have seldom used it. I
place small insects in camphine, and let them remain for months,
having previously perforated the abdomen. I find this advantage ;
the muscular structure is not destroyed, and insects prepared in
this manner present a very beautiful appearance by polarized light.

I cannot help thinking that the application of heat by means of
a water bath, would effect a great saving of time in all prepara-
tions of this character, and be very useful in very many operations
connected with microscopy.

There are three methods of applying the balsam.

1. — Place the object on the slide, and let a drop fall on it.

2. — Place a drop on the slide, and push the object into it.

3. — Place the object on the slide, cover with thin glass, and drop
the balsam at the edge, and let it run in by capillary attraction.

I do not pretend to say which of these is the best ; the student
will soon find out which is the most convenient and produces the
best results.

Drying. — Having now noticed the preparation and mounting of
the specimen, the next question is, how is it to be hardened and
finished ? This is easy to ask, but not so easy to answer. Some
authorities advise placing the slide on the mantlepiece of a warm
room, some the use of an oven after the day's fire has gone out ;
many suggest a flat metal table, heated by a gas or spirit lamp,
and others again advocate the water bath ; I have tried each of
these methods. The first is only to be advised when the student
does not wish to finish his preparation for some long period, or
when, from the nature of the object, or the presence of air bubbles,
he wishes it to dry very gradually. The oven I have found very
inconvenient, and cannot recommend it, as the degree of heat can-
not be regulated with the precision that is necessary. The water
bath I consider infinitely preferable to a flat metal table ; both
these methods are, I think, open to the same objection. When a
flat metal surface is used, the centre of the slide comes in direct
contact with the heated surface, and the heat obtained, especially
from a flat table, is more than many structures will bear without
undergoing such alteration as will render them of little value to
the student, and unless the lamp is very carefully watched and
regulated, bubbles may arise at any moment and the balsam boil.

D. E. GODDARD ON MANIPULATION WITH CANADA BALSAM. 129

The water bath — especially a small one — is much more under con-
trol, and by carefully regulating the temperature, can even be used
with advantage when manipulating with chloroform and balsam.
From many experiments and numerous disappointments, I arrived
at this conclusion. The centre of the slide should never be allowed
to come in contact with hot metal, either on a water bath or table.
I, therefore, in 1863, designed a table ; the drawings and measure-
ments are fully explained in a paper I read before the Microscopi-
cal Society of London, in January, 1864, and which was published
in the " Journal of Microscopical Science" for that year. I have
used it incessantly since that time, and I have never found it fail
when ordinary care was taken. I have left a batch of 12 slides on
it for 50 hours, the lamp burning underneath, and have never
found the balsam boil. It is impossible to boil the balsam unless
a very large flame is urged for a long time. I once imagined
that slides required long continued heat, in order to harden the
balsam sufficiently to be cleaned off. That opinion has been very
much modified ; my plan now is to submit them to a moderate
heat for some 15 or 20 minutes, and then suddenly to remove them
to a cold plate of metal of about ^th of an inch in thickness, where
they are allowed to cool. This, repeated several times, will gener-
ally be sufficient, and a very convenient method of getting rid of
any air bubble without the risk of spoiling the preparation by pres-
sure, the sudden contraction of the balsam answering the require-
ments.

Another fruitful source of annoyance is the appearance of a
white cloudiness, which spoils many carefully mounted specimens.
This may arise from two sources.

Dampness of the specimen, or the presence of grease or fatty
matter that has not been carefully removed before applying the
balsam.

If a section of any sponge, such as may often be found on our
sea coast, be mounted months after it has been gathered, this
cloudiness will ensue, because it has not been thoroughly dried.
To avoid such mishaps, I employ one of three methods.

1. — Heat, sometimes direct, but more generally by means of a
water bath.

2. — By digesting the structure in strong alcohol before placing
it in camphine.

3. — By using a sulphuric acid bath, which consists of a large

130 D. E. GODDARD ON MANIPULATION WITH CANADA BALSAM.

jar, containing a smaller one partly filled with the strong acid.
Chloride of calcium would answer the same purpose .

The object is placed on a slip of glass over the vessel containing
the drying agent, and the whole rendered comparatively air tight
by a disc of glass, with greased edges placed on the top of the
large jar. This plan I think most generally useful.

To remove grease or fatty matter, I generally employ benzole.
Unless this precaution is taken, and, say fish scales, are mounted,
the preparation will probably be a failure.

To illustrate the methods of drying with alcohol and the acid
bath, I will give an example of each.

Suppose a section of wood is required. I take a twig of any
bough — say hazel ; having cut my section, I place it in strong
alcohol, where it remains for at least one week ; it is then trans-
ferred to camphine, in both processes it is submitted to the air pump.

Again, I have injected a kidney with gelatine and carmine ; with
a valentins knife I cut the section, and as heat could not be ap-
plied without liquifying the gelatine, I place it in a vessel such as
I have described. In a few weeks it is sufficiently dry to mount ;
all the moisture having been absorbed by the sulphurie acid or the
chloride of calcium.

We now come to the final cleaning and finishing. Nothing is
more deceptive than the apparent state of the balsam. Often have
I finished a number of slides that I imagined were sufficiently set,
and in the course of a few weeks the object has entirely disappeared
in the rim of varnish.

To ascertain whether the balsam is sufficiently set, I try it with
my nail ; if any indentation is produced, I repeat the hardening
process, until, when cold, the nail only scratches.

The superfluous balsam may then easily be chipped off with a
knife. It is possible to clean slides at an earlier period. First
remove the excess of balsam with a warm knife, then brush briskly
with a soft tooth brush, dipped in mythelated spirit, and finally
wipe with a clean white handkerchief.

The size and nature of the object, and also its destination, must
decide the operator which of these methods will be most advisable.
With large objects such as wood sections, algas, &c, the balsam
need not be so thoroughly hard as when the slide consists of small
dense particles, such as diatoms, foraminifera, sponge, spicules,
sections of hairs, &c.

D. E. G0DDARD ON MANIPULATION WITH CANADA BALSAM. 131

When the cabinet for which they are destined consists of trays
in which the objects lie flat, the same care need not be taken as
when they are placed in boxes fitted with ordinary rack work.
The use of the brush is much safer than wiping the slide with a
cloth ; many a slide can be cleaned by the former method, when it
would be utterly impossible to do so without moving the cover
when the cloth is employed. Mythelated spirit, benzole, camphine,
or turpentine, and naphtha, are very good solvents for this purpose,
the first being the cheapest, and it has this advantage — it has no
unpleasant smell.

Having cleaned, the next process is the finishing. Many first-
class preparers do not use any rim of varnish. I prefer doing so,
not that I think that asphalte varnish is much protection, but
because I think it improves the appearance of the slide. I should
not advise the student to trust to asphalte alone ; it is more or
less brittle. There is another accident which must be guarded
against ; if the balsam be not sufficiently set, the varnish will run
over the field and completely spoil the preparation. To prevent
such annoyance and give still greater security to the cover, I pre-
fer running a rim of gold size round it, and when hard applying an
upper surface of varnish. I may mention that I have used asphalte
and gold size mixed in the proportion of two of asphalte to one of
gold size with great advantage.

The labels to be used vary with the taste of the preparer.
Round disks are less expensive, and look neater than others. I
have found the ruled square labels, sold by Messrs. Smith and
Beck, the most convenient, as affording room for such particulars
as are sometimes necessary.

The third division of this paper relates to chloroform and balsam.

I shall not detail the experiments that have occupied me during
the past few months ; I will simply state, in the form of a summary,
those conditions that I consider necessary to ensure successful
manipulation with this medium.

1. — Old balsam must be used, and should be sufficiently hard to
resist the impression of the point of the nail. If none is to be met
with, a bottle of ordinary balsam should be heated in a water bath
till the requisite degree of hardness be obtained.

2. — Great care should be observed in selecting the best and
purest mythelated chloroform (it is much cheaper than pure chloro-

132 D. E. GODDARD ON MANIPULATION WITH CANADA BALSAM.

form), that made by Messrs. Duncan, Hockhart, and Co., of Edin-
burgh, will be found excellently adapted for the purpose.

3. — The same precautions should be taken as when using ordinary
balsam, such as thoroughly drying the specimen, freeing it from all
fatty matter, and submitting it to the action of the air pump.

4. — Heat may be applied with advantage, but it must be with
great caution. As far as I can ascertain, it should not exceed 64
cent. (147 Fah.) On cooling, all bubbles disappear, if not at once,
in the course of a few days. The balsam hardens immediately on
cooling, when it has been subjected to a gentle heat, and is not
rendered brittle. Some specimens, such as sections of sponge, &c,
should always be allowed to dry or harden gradually, without any
application of heat.

5. — Finally, I consider chloroform and balsam an invaluable
addition to the laboratory of the microscopist, and capable of being
used with advantage in many cases in which ordinary balsams
would prove tedious and troublesome.

The effect produced by using this medium is to impart a greater
brilliancy to objects mounted in it.

I have endeavoured in this paper to trace the various operations
connected with manipulation with Canada balsam. Some of my
conclusions may be erroneous — I do not dogmatically lay down
principles. I trust that others will either verify my deductions or
prove their fallacy by experiment. I shall be most happy to re-
consider any part of this paper, and modify any of my statements,
provided I can do so on data furnished by the researches of others ;
in this age of progress, no department of science can stand still.
Perhaps others, with greater experience and more complete experi-
ments, will be able to contribute far more valuable material to our
common fund of knowledge. I only give certain deductions drawn
from the result of my own experiments, and if anything contained
in this paper is of the slightest use to any student of microscopical
science, or if it induces others to investigate for themselves, I shall
not regret having volunteered this paper.

133

On so-called Spontaneous Generation.

By Benjamin T. Lowne, M.R.C.S.

(Read September 23rd, 1870. J

When I announced a month ago that I would read you a paper
on " Spontaneous Generation," I had no idea that one of the great-
est living naturalists was going to give a most able resume on the
subject, or perhaps I should have hesitated in coming before you.
Nevertheless I feel it is a matter for congratulation that I did so,
as many unanswered questions have arisen since Professor Huxley
delivered his address at Liverpool.

Two hundred and two years ago Francesco Redi successfully
combated the then prevalent doctrine of spontaneous generation by
the most simple, nay, almost childlike experiments, such as putting
meat under fine gauze, and so showing that maggots are not
spontaneously generated. Since that day the tendency of experi-
ments has certainly been in .favour of Recli's aphorism, " Omne

vivum e vivo."

The question, however, all turns upon that little word omne, all ;
whether all living things originate from germs, or whether some
may originate spontaneously from not living matter.

Now, there can be no doubt but that there was a first cell and a
first organism which had no progenitor. Professor Huxley said
last week, that although he could not believe anything in the ab-
sence of evidence upon the subject, that " expectation is permis-
sible where belief is not ;" and that if it were given him " to look
beyond the abyss of geologically recorded time to the still more
remote period, when the earth was passing through physical and
chemical conditions, which it can no more see again than a man
can recall his infancy," he " should expect to be a witness of the
evolution of living protoplasm from not living matter."

To show you that I am not biassed in this matter, and that I am
no partisan, I tell you I go farther in my expectation than Pro-
fessor Huxley, and I think that if we could produce the conditions
we might see amcebiform protoplasm originating even yet from

134 B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION.

inorganic matter. Perhaps, as Dr. Bastian suggests, colloid may
be intermediate between inorganic and organic living material, but
I tell you, gentlemen, this is all expectation, and should not be
belief, as we have not at present a tittle of evidence in its favour.
No doubt, with Mr. Charles Darwin's hypothesis, the origin of
living organic from inorganic matter would supply a gap in
the evolution of the animal kingdom : but we must not on that
account found a scientific belief.

Now, sir, I shall very carefully sift the supposed evidence in
favour of spontaneous generation ; I shall divide this evidence
into that which is purely microscopical and that which is dependent
on experiment.

First, with regard to the microscopical evidence. This consists
in the assertion, that some observers have seen organic living cells
and fungus spores built up by the aggregation of minute granules.
Now, there is very strong evidence that this does not happen ; the
organisms described as fungus spores are in some cases not fungus
spores at all, and in other cases they have been observed with a
hilum or point at which they were attached to a parent. Surely
we cannot believe this point of attachment was the character of a
spore formed de novo.

On the other hand, I should be sorry to deny, with my present
knowledge, that it is possible organisms of a simpler kind, such as
unicellular organisms, may be built up in this way. If such a mode
of evolution does take place, I still believe it is from pre-existing
germs ; such gemmules, for instance, as Mr. Darwin believes in,
in his beautiful provisional hypothesis of pangenesis. I believe, if
it can be proved that organisms can be produced by aggregation,
it will be found that this only takes place when pre-existing cells
have given up their contents in the fluid experimented on.

In order that you may have a clear conception of Mr. Darwin's
theory, I will read to you, to my mind, far the most lucid abstract
of that theory that has ever been published. It is a portion of Dr.
Hooker's address to the British Association at Norwich, in 1868.

Dr. Hooker said — " You are aware that every plant or animal
commences its more or less independent life as a single cell, from
which is developed an organism more or less closely similar to its
parent. One of the most striking examples I can think of is
afforded by a species of Begonia, the stalks, leaves and other parts
of which are superficially studded with loosely attached cellular

B. T. L0WNE ON SO-CALLED SPONTANEOUS GENERATION. 135

bodies. Any one of those bodies, if placed under favourable condi-
tions, will produce a perfect plant, similar to its parent. You may
say that these bodies have inherited the potentiality to do so, but
this is not all, for every plant thus produced, in like manner de-
v elopes on its stalks and leaves myriads of similar bodies, endowed
with the same property of becoming new plants ; and so on, appar-
ently interminably. Therefore the original cell that left the grand
parent, not only carried with it this so called potentiality, but
multiplied it and distributed it with undiminished power through
the other cells of the plant produced by itself; and so on, for
countless generations. What is this potentiality, and how is this
power to reproduce thus propagated, so that an organism can, by
single cells, multiply itself so rapidly, and within very narrow
limits, so surely and so interminably ? Mr. Darwin suggests an
explanation, by assuming that each cell or fragment of a plant (or
animal) contains myriads of atoms or gemmules, each of which
gemmules he supposes to have been thrown off from the separate
cells of the mother-plant, the gemmules having the power of mul-
tiplication, and of circulating throughout the plant : their future
development he supposes to depend on their affinity for other par-
tially developed cells in due order of succession. Gemmules which
do not become developed, may, according to his hypothesis, be
transmitted through many succeeding generations, thus enabling
us to understand many remarkable cases of reversion or atavism.
Hence, the normal organs of the body have not only the represen-
tative elements of which they consist diffused through all the other
parts of the body, but the morbid states of these, as hereditary
diseases, malformations, &c, all actually circulate in the body as
morbid gemmules.

u As with other hypotheses based on the assumed existence of
structures and elements that escape our senses, by reason of their
minuteness or subtlety, this of Pangenesis will approve itself to
some minds and not to others. To some these inconceivably minute
circulating gemmules will be as apparent to the mind's eye as the
stars of which the milky way is composed : others will prefer em-
bodying the idea in such a term as potentiality, a term which con-
veys no definite impression whatever, and they will like it none the
less on this account.

" Whatever be the scientific value of these gemmules, there is no
question but that to Mr. Darwin's enunciation of the doctrine of

136 B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION.

Pangenesis we owe it, that we have the clearest and most syste-
matic resume of the many wonderful phenomena of reproduction
and inheritance that has yet appeared ; and against the guarded
entertainment of the hypothesis, or speculation if you will, as a
means of correlating these phenomena, nothing can be urged in
the present state of science. The President of the Linnean Society,
a proverbially cautious naturalist, thus well expresses his own
ideas of Pangenesis — ' If,' he says, ' we take into consideration
how familiar mathematical signs and symbols make us with num-
bers and combinations, the actual realization of which is beyond all
human capacity ; how inconceivably minute must be those emana-
tions which most powerfully affect our sense of smell and our con-
stitutions ; and if, discarding all preventions, we follow Mr. Dar-
win, step by step, in applying his suppositions to the facts set before
us, we must, I think, admit that they may explain some, and are
not incompatible with others ; and it appears to me that Pangenesis
will be admitted by many as a provisional hypothesis, to be further
tested, and to be discarded only when a more plausible one shall be
brought forward. 1 "

I have brought the subject of Pangenesis before you to-night
because I believe I have observed certain very remarkable changes
in the tissues of the larva of the fly prior to the formation of the
perfect insect, which have prepared me to believe it is possible
that organs or organisms are sometimes developed by aggregation
of excessively minute gemmules, such as those which Mr. Darwin's
hypothesis demands.

From observation which I made upon this subject, I found that
the semi-fluid cellular matter, from which the fly is developed, is
derived partly from the disintegrated tissues of the larva, and partly
from the fat bodies or omenta.

After the larva ceases to feed, the tissues begin to degenerate.
The muscles may be observed at this time in a state of continuous
activity, rythmic contractions commencing at one extremity of each
set of fibres, and passing regularly with a wave-like motion to the
opposite extremity. At the same time, large bright nuclei, l-1000th
of an inch in diameter, appear in rows in the centre of the muscular
fibres. These are ultimately set free by the degeneration and waste
of the muscles, and exhibit a granular appearance, but are readily'
distinguished by their great transparency and low refractive power.

At the same time a series of remarkable changes take place in

B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION. 137

the fat bodies, which consist in the adult feeding larva of flattened
hexagonal cells filled with very opaque, highly refractive white
granular matter. These cells now begin to exhibit clear spaces in
their centre, which presently become converted into nuclei exactly
like those formed in the muscles. The granular matter of the
omental cell then becomes condensed about the nucleus, leaving a
clear space around the circumference of the cell ; the cells separate
from each other, aud the cell wall undergoes disintegration.

The free nuclei developed from the muscular fibres of the larva
now begin to collect around them aggregations of molecular matter,
derived from the degeneration of the muscles and other larval tis-
sues, so that all the nuclei are soon surrounded by similar molecular
aggregations, each about l-150th of an inch in diameter.

The precise nature of the changes which take place immediately
afterwards are more difficult to observe, but after the second day of
the pupa state, numerous delicate nebulous-looking cells, about
1-lOOOth of an inch in diameter, replace some of these aggregations,
and bright nuclei, l-3000th to l-5000th of an inch in diameter,
make their appearance amongst them. The majority of the aggre-
gations remain, however, and become more dense toward their
circumference. The growth of the imaginal tissues* evidently pro-
ceeds at the expense of some of these aggregations, whilst those
which remain, undergo marked changes ; they increase in size, lose
their original nuclei, and become invested by a delicate membrane.
When the imago emerges from the pupa, a large number of these
corpuscular aggregations remain in all parts of the insect ; they
disappear during the development of the imago, and when it is
mature, not one can be detected.

If these observations are correct, there is certainly something in
the process very like the development of organisms by aggregation ;
we find nuclei aggregating around them ; molecules, which ulti-
mately become invested in a membrane, and these molecules in
turn are capable of reproducing muscles, nerves, and other tissues
similar to those from which they originated. The development of
the perfect fly from the larva seems, to my mind, a striking proof of
the correctness of Mr. Darwin's theory of pangenesis, and also to
point to the fact, that organisms may originate in a hitherto un-
known manner. Even admitting that this method of origination
is possible, we must not conclude that such organs or organisms

* Tissues'of the Imago or perfect fly.

138 B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION.

arise de novo, but rather by the aggregation, and after development
of existing germs or gemnmles.

With regard to the experimental evidence, it has been arrived at
from two classes of experiments.

The first aims at the production of known organic forms from
solutions of animal or vegetable matter. The second aims at the
production of new and unknown forms, under new conditions in saline
solutions.

I shall consider these two sets of experiments separately.

In the first, or simplest set of experiments, the most contradictory
evidence has been arrived at by different observers. The whole, to
my mind, may, however, be summed up in the following.

If we receive the usually accepted belief that the boiling temper-
ature destroys germs, we must accept spontaneous generation as a
fact. If, on the other hand, we believe that germs are not killed
in this manner, these experiments only show that if the greatest
possible care is used, germs may not be admitted and a negative
result may be arrived at, and yet that germs may find their way
into the flasks of the most careful experimenter, and may after-
wards germinate.

Now, sir, I have instituted a series of the most careful experi-
ments, which have shown conclusively to my mind that germs are
not destroyed by the boiling temperature.

I took a neutral solution of acetate of ammonia and put into it a
number of spores of the little mould known as Penicillium glaucum,
and boiled them well. I then enclosed some of the boiled fluid and
germs in capillary glass tubes, like those used for preserving vaccine
lymph. I then carefully examined the tubes by scrutinizing them
with the microscope for an hour each, and not a spore had germi-
nated, not a mycelial filament existed in the tubes. I then put
the tubes into a warm place by the stove, and in twenty-four hours
numerous mycelial filaments of considerable length had protruded
fiom many of the spores. Now, gentlemen, I should think the
most hardy advocate of spontaneous generation would hardly assert
that these spores had originated de novo, and germinated in a single
night and day.

To make the experiment more complete, I enclosed in another
tube some spores which had not been boiled, and I found about the
same number had germinated in this tube, as in those containing
the boiled spores.

I have tried another set of experiments of a similar kind. I

B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION. 139

boiled a vegetable infusion containing a quantity of the bead-like
growing mycelium of some fungus, probably a state of Penicillium,
and mounted a few portions in a cell for the microscope. I then
carefully examined and drew these portions, and watched them
from hour to hour, and saw new cells formed and new buds put out.
I have done this again and again with the same result.

I have further found that this process is arrested in sealed tubes
after a few hours ; I cannot tell why, but I strongly suspect from
the absence of dissolved air in the fluids : Mr. Cooke has suggested
it may possibly be from the absence of dissolved nitrogen. I
strongly suspect it is from this fact that we are able to preserve
meats, &c, in vacuo.

Of this at least there can be no doubt, both the growing myce-
lium and the spores of the common blue mould, Penicillium glaucum,
will grow after boiling, and it is nevertheless possible to preserve
meat, &c, on a large scale, by enclosing it in vacuo after boiling it.

I may here remark that Dr. Bastian's eighth experiment,* in
which he found that an infusion of turnip decomposed more rapidly
when enclosed in vacuo than a similar solution enclosed in a flask
containing air, is simply incomprehensible, and is a contradiction
to the well-known process of preserving meats, vegetables, fish, &c.

I think, sir, very few will believe we are justified, without evidence,
in believing a temperature somewhat higher will kill these spores if
boiling does not. I therefore look upon it that no evidence is
afforded by such experiments, — as those I have included under this
first division, — in favour of generation de novo, if my observations
are confirmed.

The second series of experiments, which aim at the production of
new and unknown organisms, afford a wider field for speculation. I
must confess, however, that in every case which I have seen, these
so-called new organisms have appeared to me undoubtedly foreign
bodies, which have accidentally gained access to the solutions.

The most recent experiments of this kind were carried out by
Dr. Bastian, and their results have been published in " Nature." In
these experiments a solution of sodic-phosphate and ammoniac car-
bonate was enclosed in vacuo whilst boiling, and certain spiral fibres
and portions of a fungus, like Penicillium in fruit, were found after
a time in the solutions.

With a view to discover whether the spore-bearing portions of
Penicillium would remain unaltered after boiling, I tried the unripe

* " Nature." Pt. xxxvi., p. 194.

140 B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION.

spore-bearing filaments, and found that they were not altered in
their appearance by such treatment. The ripe spores are, however,
immediately scattered by contact with fluid. Now I can readily
understand why no fungi were discovered until after a long lapse
of time, in Dr. Bastian's solutions ; although some might have
been present from the first. I find solutions of sodic phosphate
throw down a flocculent precipitate after a time, and in those speci-
mens which Dr. Bastian was courteous enough to show me, I
observed that the object was surrounded by just such a precipitate,
which he called correctly enough granular matter. I suspect the
collection of such a flocculus around the fungus drew his attention
to the spot where the minute mass of fungus was.

Another reason for not believing that the fruit-bearing stems of
Penicillium, which Dr. Bastian figures, were formed in the solu-
tions, is that these fungi never fructify in fluid. My friend Mr. M.
C. Cooke tells me that he never heard of any fungi, except such as
are parasites on insects, fructifying in fluid, or so long as a plentiful
supply of fluid is present. As he very forcibly put it, take the
vinegar plant as an example ; so long as there is plenty of fluid, it
never produces fruit ; but take it out of the fluid, and its surface
will soon be covered with blue mould. With regard to the so-
called spiral £bre organisms of Dr. Bastian, they have puzzled me
very much. I never, however, believe but that they were some very
common accidental material which had found its way into his solu-
tions. I observed that he only found these " organisms" in solutions
containing sodic phosphate. I have tested and had tested for me
three samples of crystals of this salt, and in all free soda was pre-
sent. I have since tried the action of very dilute solutions of
caustic alkali on various kinds of organic fibre, and have found wool
fibres, minute particles of feathers, and some kinds of spiders'
thread twist into spirals under its influence. Now, the spirals pro-
duced from spider's silk correspond most closely with Dr. Bastian's
spiral fibre. In my own mind I have no doubt the specimen he
kindly showed me was spider's silk.

At any rate I do not think, in the face of this, we ought to
conclude that we have discovered spontaneous evolution from the
appearance of spirals in an alkaline solution.

I apprehend then, sir, from what I have said, if my experiments
are confirmed, which can easily be done, that at present, let our
" philosophic faith be what it may," we have no evidence whatever
of spontaneous evolution.

141

Mobility op Spines on Certain Insects' Eggs.

By H. Davis, F.R.M.S.

(Communicated by Mr. Curties. August 26th, 1870.)

The following communication from Mr. Davis, addr ssed to Mr.
Curties, was read by that gentleman : —

Encouraged by your opinion that my observation of the mobility
of spines on certain insects' eggs, would be a suitable offering to
the Quekett Club, I venture to send some brief notes thereon, a
few objects and illustrative drawings for exhibition at the meeting,
and a parcel of photographs for distribution among the members.
The discovery, such as it is, is a simple matter, and lies in a nut
shell, or rather in an egg shell. You know that the eggs of some
bird parasites have lately attracted much attention from their
novelty and peculiar beauty ; foremost among them, the eggs found
on the black* quilled Peacock, and on the Mallee bird: now the
elegantly curved petaloid spines on the former quickly uncurl,
straighten, and contract on the lid ivhen the egg is placed under
water. They remain thus closed until the water is removed, when,
as the egg becomes dry by evaporation, the spines loosen ; they
gradually and gracefully recurve until the egg again assumes its
flower-like form. A group of these eggs in drying make a pretty
sight in the microscope, — it is a bouquet of flower-buds actually
blooming under the eye of the observer.

The action of the spines seems independent of vitality, and is
renewed apparently as often as moisture is applied or removed ;
thus, on one of my slides, some of the lids are gone and the shells
empty, while the contents of other unhatched eggs are
shrivelled and dead ; still all the spines continue to contract and
expand on provocation after a score of immersions.

The parasite eggs found on the Mallee bird possess appendages
actuated precisely as^are those of the species described ; these are

Journ. Q. M. C. No. 13. l

142 H. DAVIS ON MOBILITY OF SPINES ON CERTAIN INSECTS' EGGS.

the only two I have examined, but it is likely that a few experi-
ments with water on some of the many insects' eggs which bear
spines and wing-like processes, would lead to interesting results :
desirable also is careful examination with a view to detecting the
cause of the spines uncurling when wet. An unequally greasy
appearance in the eggs when partly dry, leads me to think that one
side of each spine is much more absorptive than the other, a quality
which would readily account for its activity in water ; but this is a
mere suspicion, and of no scientific value.

Without pretending to any exclusive knowledge of Nature's
object and intentions in this case, and indeed, making only a
modest guess at them, I may suggest the probability that the
contracted state of the spines over the lid in wet weather only,
strengthens and bars that outlet for the time, perfectly restraining
the hatching of even mature eggs until the advent of dry favour-
able weather.

The tender provision for the meanest of insects implied in this
arrangement is most obvious ; the inevitable pointed moral being
equally so, I am left but a single reflection to conclude with —
thrice happy are those creatures who are well provided against a
rainy day !

143

Sections of Coal.
By J. Slade.

(Read October 28th, 1870.J

The origin of coal has ever been a subject of great interest to the
naturalist ; but so far as the microscope has been concerned in the
investigation, no satisfactory progress has been made until quite
recently.

The examination of sections of coal under low powers, either as
transparent, or opaque objects, is almost useless ; but sections
averaging between the two and three-hundredths of an inch in
thickness, under a quarter, or an eighth objective, show a structure
as unmistakably as do sections of recent vegetable organisms. The
teachings resulting from examination of such sections have been truly
and clearly brought before the public by Professor Huxley in a lec-
ture at Bradford in January last, and again at Leicester in November
last, and reported in the " Contemporary Review." The means
of confirming these observations is in the hands of anyone accus-
tomed to prepare objects for the microscope, while the material is
close to our hands at any moment. The method of proceeding is
as follows : —

A piece of coal being selected, a surface is at first obtained
roughly by a file, or piece of sandstone ; then a finer, by means of
a hone, or piece of fine glass paper ; then a still finer, by means of
pumicestone, and after rubbing upon Arkansas stone, finally brought
to the highest polish possible by friction upon plate glass.

If the coal be very friable (which it sometimes is), it will be
necessary to macerate the specimen in thin shell lac varnish and
dried, before the whole process can be accomplished.

In order to secure success, it is impossible to bestow too much
pains in this preliminary operation.

Having made a good surface, next cement it to a glass slip by

l 2

144 J. SLADE ON SECTIONS OF COAL.

marine glue ; the marine glue used, requires careful selection; that
usually sold frequently contains particles of the undissolved
materials, which are visible enough under the microscope.

However, having obtained the right sort, cut thin slices ; lay
them upon the glass slip, and melt over a flame; when thoroughly
melted, drop the specimen (the polished surface being downwards)
into it, and press out the air bubbles When air bubbles appear
between the glass and the surface of the coal — which they often do,
and sometimes prove very annoying — they must be got rid of ;
otherwise it is useless to proceed, for long before the specimen is
thin enough to show structure, the coal over the air-bubble comes
away, leaving a hole. If they be not present, the preparation may
be proceeded with, first reduced on sandstone, and then finished by
pumicestone ; and after scraping away the superfluous marine glue,
mounting in Canada balsam, and covering in the usual way.

As the preparing goes on, the specimen will be occasionally
viewed under the microscope. The first to appear will be the spore
cases, and a careful continuance of the grinding will finally render
the spores visible.

Spores and spore cases are to be found in every successful pre-
paration of coal ; but their relative proportions and degree of pre-
servation vary considerably ; thus Wigan Cannel almost entirely
consists of spores, very few spore cases. Bradford coal, 6pores and
spore cases in nearly equal proportions. Silkstone coal, spore cases
few, and much compressed spores in abundance. Moira coal, Lei-
cestershire, spore cases beautifully preserved, and in some, spores
in situ. Dalkeith coal, the same, the spore cases, on the whole,
being slightly more compressed. Wallsend, spore cases much com-
pressed and altered, and mixed up with a quantity of grit and
amorphous bituminous matter. White coal, of Australia, consists
almost entirely of spore cases.

145

On a Neutral Tint " Selenite Stage."
By W. Ackland.

{Read November 25th, 1870.)

la using polarized light with the microscope, many objects
possess so slight a depolarizing influence, that a selenite film must
be used to bring out some structure not otherwise visible, or a dis-
play of colours that could not otherwise be obtained.

Selenite films, yielding the various tints of blue, green, yellow,
red, and purple, are commonly employed ; but, anyone using these,
must have noticed, when viewing an object not entirely filling up
the field of view, that the colour of the background thus formed
fails to harmonize with the colours of the object under examination ;
and, indeed, more frequently the effect is considerably marred by
want of contrast.

Now, my object in addressing you this evening is to recommend
you to try the neutral or pale bluish violet colour, corresponding to
the tint that occurs in Newton's rings, between the violet of the
second and the indigo of the third wave, and as used by Soleil in
his Saccharometer.

This tint cannot be readily. obtained by splitting selenite, but is
easily produced by superimposing two suitable films ; and, when
thus obtained, is exceedingly delicate in action, as its colour is
varied by the slightest depolarizing influence of the object under
examination ; indeed, it is often changed to either violet or blue by
the action of the thin glass cover, or a slight tension of the mount-
ing medium.

To gain the fullest advantage of this neutral tint, I have devised
an efficient, but simple selenite stage, which, when in use, is laid on
the microscope stage and the object on it.

It consists of two films — one the primary, capable of being
rotated by the milled head on the right-hand side, and the second,

146 W. ACKLAND ON A NEUTRAL TINT " SELENITE STAGE."

or compensating film, which is rotated by the finger being pressed
against its projecting milled edge.

When used, first rotate the polarizer, or analyser, until a dark
ground is obtained, then remove the compensating film, and place
the selenite stage on that of the microscope, rotate the primary film
until its greatest intensity of colour is obtained ; now add the com-
pensating film, and rotate that by the finger until the colour is
changed to a light neutral tint, midway between reddish purple and

indigo blue.

This being obtained, place the object to be examined on the
selenite stage and focus it.

Now, if the thin glass covering of the object has changed the
tint of the background, rotate the compensating film until the
neutral tint is restored ; then notice the effect produced, and vary
slightly the position of both primary and compensating films until
the maximum brilliancy is obtained ; but, it may be noticed, that
with some objects possessing very slight depolarizing influence, the
maximum effect is yielded when the primary film is first rotated
(not as above advised until it yield the greatest brilliancy of colour),
but when rotated until its brilliancy is nearly at a minimum.

Indeed, each object will require some slight variation of position
of one, or even of both films ; but these are easily found by trial.

In conclusion, I boldly assert, that with this simple stage, any
object requiring its use can be seen to as great, if not greater,
advantage than with selenite stages of treble the cost, and that the
neutral tint I advocate will shew all of our ordinary polarizing
objects far more effectually than when viewed with the ordinary
selenite films ; but, should variation of colour be deemed necessary,
the mere rotation of the compensating film will at once yield an
abundance of tints from which to select.

147

PROCEEDINGS.

September 23rd, 1870. — Chairman, Dr. Lionel S. Beale,

F.R.S., President.

The following donations to the club were announced : —

from the Editor,
the Publisher.

J

" Land and Water," (weekly)

" The Monthly Microscopical Journal"

" Science Gossip "

11 The American Naturalist " ...

Keport of the Surgeon General of the U.S.
Army, on certain points of the Histo-
logy of minute blood vessels, illus-
trated by 13 micro-photographs ; also
his report on the use of the oxy calcium
light in micro-photography

Cooke's Handbook of Fungi (Part 1)...

Dr. Deane's Work on the gray substance
of the Medulla

Dr. Brewster's Treatise on the Microscope

25 Slides of Marine Algae

1 Slide of Winged Seed

3 Slides of Chigoes

1 Slide of Gizzard of Cockchafer

The thanks of the club were returned to the donors.

The following gentlemen were balloted for and duly elected members of the
club: — Mr. George Cheverton, Mr. Rochfort Connor, Mr. William Delamore,
Mr. Lamartine Burdett Yeoman.

Mr. B. T. Lowne read a paper upon " So-called Spontaneous Generation and
the recent experiments described by Dr. Bastian."

A vote of thanks to Mr. Lowne for his elaborate and interesting paper was
proposed by the President and carried unanimously.

Mr. M. C. Cooke said that although he did not intend to make any remarks
upon the theory of the subject, he could not help doing so upon some of the
facts. As for agglutinated atoms forming fungus spores, he could only say
this was so extraordinary that he should be very glad to see the fungus spores
so formed, more especially because it is not so easy to say what is a fungus
spore and what is not. There were very few — he might say there were none —
which gave no evidence of a pedicel, so that if these bodies were fungus spores

in exchange.

Lieut.-Col. Woodward.

Mr. Quick.

Mr. M. C. Cooke.

Mr. C. Adcock, of Jersey.
Mr. C. Collins.
Dr. Gray.
Mr. Quick.

148

they would certainly show a pedicel. He then quoted from some papers by

Hallier, in which the budding out alluded to had been described and figured.

With reference to fungi fructifying in fluids, he believed tbey had never been

known to do so; no forms do so excepting those found on flies and on fish, and

which, after all, were doubtful species. As for a Penicillium with spores in situ

being found in a fluid, he should be glad to see such a remarkable phenomenon,

for it is well known that moisture prevents its fructification. Take a Penicillium

which has formed under the cover of a glass slide, and let a little water go

under the cover, and instantly every head will fly off, you cannot get the heads

to remain on after moisture has touched them. The vinegar plant was another

instance ; it would grow rapidly but would not fructify so long as it had plenty

of moisture ; but take it out of its moisture, and it would in a very short time

throw up its filaments and produce fruit.

Mr. Lowne said that some of the things which .were said to be the spores of
fungi certainly had a hilum, and Mr. Smith had pointed out that it was very
strange that a thing should have an umbilicus if it never had a parent. With
regard to the Penicillium, he believed that the specimen found in the fluid was
unripe, and in this state it might remain entire ; it was when ripe that the
heads flew off upon contact with moisture.

Mr. Golding expressed himself as being very much indebted to Mr. Lowne for
his paper, which he believed had thrown considerable light upon this question.
He could not help believing that there was a distinction between organic and
inorganic matter, and that there was something that we called life. He
thought that the evidence seemed conclusive that there were germs inthefluid3
experimented upon, and Mr. Lowne had certainly shown most conclusively that
under his own hands germs which had been boiled had not been destroyed by
the process, so that it might reasonably be believed that those found in the
fluids ' f Dr. Bastian had passed safely through all the ordeals which he had
detailed. He thought Mr. Lowne deserved espechil thanks for the very great
pains he had taken to ascertain what those remarkable forms were which had
been found in the fluids.

Mr. T. C. White wished personally to thank Mr. Lowne for his paper, and
especially for the suggestion which he had thrown out, that the members of the
club should take this subject up. He hoped the suggestion would be acted
upon, and proposed that at the meeting to be held on March 24th, 1871, those
members who were willing to lend their aid w ould come prepared to give the
details and results of experiments made meanwhile.

Mr. Collings said that some f'oubt appeared to be thrown upon the statement
that all the drawings of Dr. Bastian had been made upon the same scale ; he
had himself made the drawings, and could say that he had in every case used
nothing but one of Nachet's l-12th inch immersion lenses, which had since
been returned, and was now besieged in Paris.

Mr. Lowne inquired if the drawings had been made by camera, and upon
ruled squares, and was informed that they were.

The President said he was greatly astonished to hear that the drawings had
been all made under the same power ; it made them quite incomprehensible.

Mr. Lowne said it certainly made the matter much easier to dispose of.

The President observed that there were many drawings made under powers
of 2,500 diameters, which seemed far less amplified than those under considera-
tion.

The President having intimated that, as an advocate in the controversy, he

149

would rather not speak upon it from the chair, since he could not well be both
advocate and judge. The chair was taken pro. tern, by Mr. Henry Lee, V.P.

Dr. Beale then spoke at considerable length upon the subject, ob-
serving that Mr. Lowne had drawn attention to the idea of the formation
of living germs by aggregation, but his own conviction was that they
were never formed by aggregation. When carefully examined under a
very high power small particles might be seen to detach themselves,
but no one had ever seen two particles coalesce except in the case
of generative organisms. Statements of this kind must, therefore, be
received with extreme doubt ; indeed, after careful attention to the subject,
everyone must come to the conclusion that the general characteristic of living
matter is that a particle having attained a certain size divides. After reference
to the observations of Pouchet, the speaker said that it would no doubt be in-
teresting to the members to hear that quite recently the experiments of Dr.
Bastian had been repeated with great care by Dr. Child in the laboratory at
Oxford. Last week Dr. Child and himself had carefully examined the fluids in
the flasks, and he must own that the results were very unsatisfactory for Dr.
Bastian. They found here and there some very minute Bacteria, so small
that they must have been overlooked by Pouchet, and in some there certainly
were living organisms, yet they still had, as a general conclusion, these facts,
that the more care they took in boiling, sealing, and keeping at a high tempera-
ture, the fewer were the germs to be found, and it seemed probable that if it
were possible to conduct these experiments with perfect care, then no germs
whatever would be found. He confessed that he could himself as soon believe
in the spontaneous generation of a mouse, or a rat, or of an elephant, as of any
other living organism, the one seemed to be the same in principle as the other ;
if it were not so, then there must be somewhere a line separating nature into
two distinct parts. If this principle of spontaneous generation were to be ad-
mitted as proved, then all that one held with regard to the higher animals and
of the connection between matter and mind must be swept away. The stake
was tremendous. He felt most strongly that the moment he became convinced
of this then the whole of his views in this world must be changed. He thought
that it was quite right that experiments of this kind should be conducted, but
they ought obviously to be conducted with the greatest care, and with regard to
thos9 described by Dr. Bastian, he must confess that there appeared to him to
have been some very great mistake, because there are, amongst the things
figured, some which are comparatively high in the scale of nature, the size also
of some of these things as represented also led him to believe that some error
must have been made. He would also like to say something on the subject of
pangenesis. In many persons it was well known that there were evidences to be
found of the peculiarities of their predecessors, and these were to be found in
the brain cells, in the nerves, as well as in colour of the iris, and conformation of
the features ; how was this to be explained ? They had recently had some
strange ideas propounded by Tyndall, who says that "the earth is surrounded
by a medium " which he calls "spirit and matter united together," and that
"all the blue sky can be packed in a person s trunk, and that it all consists of
germs." What could he mean ? For a cell germ to be produced as imagined,
the particles must be capable of passing through tissues and through substances
as hard as bones and teeth, and these bodies must be detached at all periods of
life. The susceptibility of children to the parents' diseases was well-known, as
also the fact that particular diseases were developed at the age at which they

150

had appeared in the parent, so that if the child passed this period of life, the
system seemed to lose its susceptibility for that particular disease. How these
matters were to be explained by the Pangenesists he did not know,

Mr. Lowne, in reply, thought that it was not more strange that germs should
pass out of cells than that nutriment should pass in.

A very cordial vote of thanks to Mr. Lowne was then unanimously carried,
and the proceedings terminated with a conversazione, at which the following
objects were exhibited : —

Aphides on Lysimachia Nummularia by Mr. Hain worth and Mr. Quick.

Gizzard of Cockroach , , Mr. Quick.

Triceratium, Stylodactylis Mr. Meacher.

Section of Cannel Coal Mr. Slade.

Crystals of Borate of Ammonia ... Mr. Conder.

Caprella Lobata Mr. T. C. White.

October 28th, 1870 — Chairman, Dr. Lionel S. Beale, F.R.S.,

President.

The following donations to the Club were announced : —

" Land and Water " (weekly) ... ... from the Editor.

" The Monthly Microscopical Journal " ... the Publisher.

" Science Gossip " ,,

" The Popular Science Review " ,,

"Archives of Science and Transactions of i

the Orleans County Society" ] in exchange.

" The American Naturalist " „

"Proceedings of the Brighton and Sussex -\

Natural History Society," and " The > the Society.

Moss Flora of Sussex," by Mr. C. P. Smith )

12 Slides of diatoms Mr. A. C Cole, Liverpool.

1 Slide .. Mr. Tatem, Reading.

" Land and Fresh Water Shells" Mr. T. Gibson, Liverpool.

" Synopsis of British Sea Weeds," by Pro- t

fessor Harvey } Mr. Jno. Michels.

The thanks of the Club were returned to the donors.

The following gentlemen were ballotted for and duly elected members of the
Club :— The Rev. F. H. Allen, Mr. C. H. Golding Bird, B.A., Mr. W. A. Green,
Mr. A. J. Johnson, Mr. W. Kean, Mr. M. G. Williams.

Mr. J. Slade read a paper "On the Microscopic Characteristics of Cannel
Coal, and the method of preparing coal sections for the Microscope." The sub-
ject was illustrated by diagrams.

A unanimous vote of thanks was passed to Mr. Slade for his paper.

Mr. Suffolk inquired how Mr. Slade got rid of the remains of the marine glue
previous to mounting his finished coal sections.

Mr. Slade said that he had not found it necessary to attempt to get rid of it,
the sections were mounted without detaching them. In reply to a question
from Dr. Matthews, Mr. Slade said that he believed that coal naphtha would act
as a solvent of marine glue.

151

The President observed that everyone present must have noticed with great in-
terest Mr. Slade's mode of preparing these sections successfully, in which the
use of marine glue was a good example of a " little dodge,'' such as is acquired
only by experience. Everyone must have noticed the difficulty with balsam, that
from its brittleness it frequently broke up at the last minute and spoiled the
specimen. Marine glue was evidently the substance which prevented this catas-
trophe, and it would doubtless occur to others that marine glue might in other
instances also lead to success where balsam had failed.

Mr. W. T. Suffolk said that he had written no paper, but had simply come for-
ward in obedience to a wish that small matters of interest might be brought be-
fore the Club. One evening recently, two friends called upon him, and the
newest thing in the house being a cheap 1-sixteenth inch objective, they pro-
ceeded to try it. Yalisneria spiralis was at hand, and was at once placed upon
the stage. Unfortunately, however, Yalisneria would not work on that occa-
sion, as is sometimes the case, but they discovered something going on in the
cells, a kind of movement of rotation which closely resembled something which
is sometimes seen going on in Closterium, and which is known as " swarming,"
that curious movement of particles uot more than l-20th the size of the grains of
chlorophyll, rather flattened, and of a bright green colour. He had never seen
these granules in motion like this in Yalisneria, where the cyclosis was going
on. Whether, therefore, it was an action of life, or whether it was an action of
decay, was a matter, he thought, which further observation would throw light
upon, and he had therefore thought it worth bringing before the members of
the Club. Although upon the occasion he had mentioned, a very high power
was used, yet he believed a half inch objective might do very well for the pur-
pose, provided black field iilumination were used.

Mr. T. Crook said that the circulation described by Mr. Suffolk might be very
well seen in a little conferva, the Spirogyra. If carefully examined, this move-
ment might be seen going on actively ; it was like a number of very minute
granules in constant rotation and movement about each other without any cir-
culation like the cylosis in an ordinary plant.

Mr. T. White expressed his obligation to Mr. Suffolk for bringing the matter
before the Club ; he thought that the question of molecular movement was one
of great interest, and one about which all would be very glad to know more. He
had observed this kind of motion going on in other things beside plants ; some
time ago he mounted a female Cyclops in some of the water in which it had been
caught, and it remained there for about two years before it broke up. During
part of that time, whenever he looked at it, this molecular motion was seen
going on inside, and was kept up for about seven months. He was, therefore,
inclined to think that it might be the result of the process of decay which
was going on.

Mr. Suffolk observed that he was inclined to think that this motion differed
from the swarmiug seen in Closterium, because that went on whilst the Clos-
terium was in full vital action.

A vote of thanks to Mr. Suffolk for his interesting communication was pro-
posed by the President, and carried unanimously.

The Secretary announced to the meeting that he had recently received a letter
from Mr. T. W. Wonfor, the Secretary of the Briguton and Sussex Natural
History Society, announcing that he had, as Secretary of the Quekett Micro-
scopical Club, been elected an Honorary Member of that Society. In the name
of the Club he had written to thank Mr. Wonfor for the honour, and had for-

152

warded him a complete set of the Journals, for which he had received a letter of
tbanfcs, and copies of the Society's proceedings. Mr. Wonfor, in his letter,
expressed a desire that this interchange might be r yarded as something more
than an indication that they were associated merely by ties of kindred pursuits,
and he requested that it might be made known to the members, that should any
of them be visiting Brighton, they would at all times receive a hearty welcome
at the Society's Meetings.

The proceedings then terminated with a conversazione, at which the following
objects were exhibited : -

Wing of Lasiommata Megsera ... ... ... by

Wing of Dragon Fly

Ustilago Maydis, &c.

Licmophora flabellata

Circulation in Spider

Cellalaria Avicularia

Lnciniolaria socialis

Pleurosigma hippocampus — shown with l-8th ?
in. immersion lense and prism ■>

Chelifer cancroides

Sections of Coal, showing spores and spore cases...

Also for distribution amongthe members, fronds') ^ r m T

B/i , , „ . \ from Mr. R.T.Lewis.

of Ceterach omcmarum ... ... .. ...)

Mr. W. J. Brown.
Mr. Collins.
Mr. Conder.
Mr. Curties.
Mr, Fitch.
Mr. Golding.
Mr. Hain worth.

Mr. Jackson.

Mr. Oxley.
Mr. Slade.

November 25th, 1870 — Chairman, Dr. Lionel S. Beale, F.K.S.,

President.

from the Editor

the Publisher.

founds
T. R.V

the Author.

'}

The following donations were announced : —

" Land and Water" (weekly)

"The Monthly Microscopical Journal"...

"Science Gossip" ...

"A Report on the Microscopical Objects
in Cholera Evacuations," &c, by Mr.
Lewis, M.B.

A paper "On the Structure and Affinities of the-
Genus Dicranograptus," by Mr. John Hopkin-
son, F.G.S.

The thanks of the Club were voted to the donors.

The following gentlemen were ballotted for, and duly elected members of the
Club —Mr. Edward C. Baber, Mr. Herbert J. Barnes, Dr. A. Fyfe, Mr. S. J.
Goldsmith, the Rev. Wyndham M. Hutton, Major Lewis Jones, Mr. William
Ladd, F.R.A.S., Mr M. M. McHardy, and Mr. John F. Tate.

Mr. Ackland read a paper, descriptive of a new Neutral Tint Selenite Stage,
which was exhibited to the members.

Dr. Matthews said that he was the happy possessor of one of these little
instruments, and could testify personally to its great value ; he had never seen
polariscope objects so harmoniously coloured as they were by its use.

The President proposed a vote of thanks to Mr. Ackland for his communica-
tion, which was carried unanimously.

153

Mr. James Smith exhibited and described, a new shade for a microscope lamp
chimney, which he had designed to obviate the many disadvantages of an ordi-
nary paper shade. It was made of a piece of thin sheet metal, ri vetted to-
gether in the shape of a hollow truncated cone, and was fitted to slide upon the
upright rod at the back of a " Bockett ' lamp. A semi -circular piece was cut
out of the base of the shade in front, so as to admit of the free use of the bull's-
eye condenser, and the inside was coated with whitewash, which gave it a
smooth, reflecting surface, and could, when discoloured, be easily renewed in a
few minutes.

The President proposed a vote of thanks to Mr. Smith for his ingenious im-
provement of the " Bockett" lamp, which not only increased the light, but at
the same time shaded the eyes, and, he thought, would also intercept some of
the heat.

Mr. T. C. White said that nearly every one must have been troubled with
lamp shades, and would consequently be very glad to see any improvement in
them ; the paper shades frequently got scorched and burnt, whilst the metallic
chimneys got inconveniently hot — he had himself burnt his fingers badly with a
Fiddian's chimney whilst attempting to shift it during the time he was adjust-
ing his microscope to get the proper degree of light through his camera lucida.
He called upon a member of the Club one day, and was shown by him a very
simple and effective kind of lamp shade, which, he thought, was worth men-
tioning. It was formed of a piece of millboard, pasted on one side and rolled
round a brandy bottle ; as soon as dry it was removed from the bottle, was
blackened outside, and was then ready for use.

A vote of thanks to Mr. Smith for his communication was then put to the
meeting, and carried unanimously.

The President said that he had been pressed to fulfil a promise made some
time ago — to offer a few remarks upon the subject of injecting ; the difficulty in
the matter, however, was that the subject was a very large one, whilst the time
at disposal rendered it necessary to condense very greatly ; he would, however,
do his best to give the members some information as to how they should pro-
ceed in injecting the tissues of any of the higher animals. With most persons
the idea probably is that an injection is made for the purpose of exhibiting the
vessels, and in this respect those made now were scarcely better than what were
made many years ago by Leeuwenhock and others ; it was, however, a mistake
to suppose that it is only of use to show the vessels — it had a much more im-
portant use than that in rendering also visible the structure of the tissue them-
selves, to properly understand which preparation is always necessary. It might
be said that the best way to examine a tissue was to see it as it existed natu-
rally very soon after death, but there were many structures which, if only
treated in this way, would be totally overlooked. The cornea of
the eye, for instance, is the most transparent tissue in the human
body, and it might be said that any structure in it must therefore
be seen at once ; but this would be a terrible mistake, for before you could
properly examine it, it must be carefully prepared in a proper manner, and in
preparing it you must proceed according to certain principles. In every part of
the cornea there are little bodies to be found, and these are disseminated at
every possible level throughout its structure, and cannot possibly be demon-
strated when the cornea is exhibited in the ordinary way ; these bodies have
been discovered some time, but new points still continue to be made out. There
are also in the cornea other things, there are nerves quite invisible when ex-

154

amined in "the ordinary way, and to see which you must proceed in such a way
as to make the nerves more opaque, but at the same time keep the tissue of the
cornea transparent. And what is true with respect to the cornea is true also of
every tissue of the body. When it is intended to introduce artificial fluids into
the vessels of an animal, the best way would seem to be by introducing them
through the channels in which the natural fluids would pass during life., and a
person is next led to try experiments as to the best fluid to use for the purpose,
and the best kind of colouring matter, and it would be found that the best fluid
is glycerine. Syrup would do as well in the first instance, but it decomposes,
and also is apt to carry with it crystals of the sugar. Glycerine, when intro-
duced into the large vessela of the body, readily diffuses itself into the small
vessels, and through their walls into the tissues, in the most complete manner.
In all the old preparations, and in the Ger man specimens, nothing could be
more beautiful than tbe appearance of the vessels ; but the structure of the
tissues was gone and nothing could be learnt of it. In order to make out the
most minute points of a texture, it must be immersed in a suitable fluid, and
there were some which required that an acid base, or an alkaline base — as the
case might be— should be mixed with the glycerine. A colouring matter must
also be used, and this must be perfectly suspended in the proper solution.
Formerly it was customary to inject with a fluid, in which was suspended an
opaque colouring matter, such as vermilion or red lead but the particles of
these pigments are frequently too large to go through the capillary vessels, and
this necessitated the most careful watching during the process of injection, be-
cause if the coloring matter was suspended in glycerine, and the pressure was
continued after such an obstruction had taken place, the vessels would break,
and the preparation would be rendered entirely useless. A finer coloring
matter is therefore needed for the purpose, and it was found that Prussian blue
was the best, as it could be obtained in a more finely divided state than any
other known substance ; no heat was required in its preparation, and it was so
fine as to remain suspended in the glycerine so perfectly as not even to require
shaking ; it was also inexpensive, and could be made for about Gd. per pint.
Everyone should make his own fluid, it was easily made from a mixture of Fer-
rocyanida of potassium, dissolved in water, and glycerine ; and perchloride of
iron, in water, and glycerine ; the one should be added to the other by degrees,
and the mixture shaken well each time, it was important to notice that the
solution of iron must be added to the Potassium, and not the potassium to the
iron. When made properly the solution would hold the particles of blue in
suspension so perfectly that they would not subside, and the strength of the
fluid could be easily altered by diluting it with water according to the fineness
of the work to be done. Dr. Beale then exhibited to the meeting some of the
prepared injecting fluid of good quality, and in order that members might prac-
tically understand the process, he asked his friend, Mr. Perrin, to prepare one
or two animals for the purpose of being injected before them. By proceeding
in the manner about to be described it was possible to inject every particle of
tissue, no matter what, either of the larger and higher animals, but also of
reptiles and others, and a perfect injection of the choroid coat of the eye could
be made in the course of a few minutes ; the glycerine was also a preservative
fluid. Many persons were sceptical as to the value of examinations of injected
preparations with higher powers than those obtained by a 4 m - objective, but
some injections were capable of beiug examined under very much higher
powers, the papillae of the tongue of a frog, for instance, when injected

1 "" "

loo

were so perfect that they would bear examination with a 1 50th inch.
He regretted much that many assertions had been made as to the
uselessness of these high power injections, and he was quite prepared
to produce specimens and to meet anyone— Mr. Huxley if he pleased — in
order to put the matter to the test. Mr. Huxley should then make a drawing
of the specimen under a l-12th inch objective, and he would himself make one
under a much higher power ; he would then ask Mr. Huxley to do the same,
and they would then see whether very much more had not been made out under
the higher power than with the lower one. It appeared to him to be a most
unwarranted statement to say that everything there was to be seen in these
preparations could be made out with one of Eoss's l-12th inch objectives ; and
he thought it a great pity that Mr. Huxley would not come forward and rjut
the matter to the test. In proposing such a trial as he had mentioned, he
must make it a proviso, that the specimen to- be examined had not been seen
before, but that each observer must then see it for the first time ; for it was
well known that after a person had conned a structure over under a l-50th in.,
he could see muc i more in it with a l-12th inch than he could have been able
to do before. He could not himself see at present any limit to the usefulness
of magnifying powers, every improvement in which must, he believed, give an
increase in results, carrying us on in the way from point to point. Dr. Beale
then called attention to a number of coloured diagrams, which were exhibited
in the room, to illustrate some of the results obtained by injections, and, in some
instances, also the failure of the process from the too great siee of the particles
of colouring matter employed for the purpose. Another point with regard to
the use of injecting fluids was that a number of other processes may be carried
out by means of them- He had been in the habit of demonstrating in this way
the existence cf masses of living matter, and it had been shown that an alkaline
solution containing a colouring matter — such as an alkaline solution of carmine
— had the power of colouring the bioplasm ; it passed through the walls of the
vessels, and coloured all the germinal parts, but did not colour the other parts,
the striking point being this— that the living matter was coloured, bnt the non-
living matter was not coloured. A person who attempted these injections must
make up his mind to fail a number of times; he would at length, however,
begin to obtain some amount of success after a few trials, and then, stimulated
and encouraged by this, he might go on, until by-and-bye he would no doubt
obtain some very excellent results. Before proceeding to give the members a
practical illustration of the process, he would say a few words with regard to
the preparation of specimens to be injected. Very much of the chance of
success depended upon the way in which the animal was killed, and upon the
time at which the injection was made. It was generally performed some time
after the rigor mortis had passed off, because until it has done so the passage of
the injecting fluid would be stopped in consequence of the strong contraction of
the muscles ; but if a person waited until it had passed off (which it did in 12
to 24 hours after death), the most delicate portions of structure would already
be decomposed, for decomposition, especially in the summer months, takes
place very shortly after death. If, however, the animal was killed suddenly,
by shock, and was immediately operated on whilst all the muscles were in a
state of relax, the tissues could be most perfectly injected, just in the condition
in -which they had existed at the moment of life. Dr. Beale then proceeded to
demonstrate the process which he had described, by injecting the body of a
white rat, which, during the delivery of his remarks, had been killed, and pre-

156

pared for the purpose by Mr. Perrin. A small pipe having been introduced into
the pulmonary artery, and tied round, it was fixed to a syringe, filled with the
blue fluid, which was then forced into the artery by the pressure of the hand,
and, passing thence into the smaller vessels throughout the body, soon forced
out the natural fluids of which it took the place. In about two minutes the
feet of the animal begun to turn blue, showing how completely the fluid had
pervaded the whole system ; and the lung was then removed, and handed round
the room for the inspection of the members, who were thus enabled to see how
completely successful the operation had been. A frog was next experimented
upon, and the injection of the lung was again perfectly successful ; after which
a second rat was injected, and showed very clearly the complete manner in
which the injecting fluid had filled the smaller vessels of the ears, eyes, and
tongue. Injected specimens of various kinds— some injected with several
colours — were exhibited by means of portable microscopes, which were passed
round amongst the members ; and after giving a few further practical hints as
to cleanliness, pressure, cleansing in cases of extravasation, &c. Dr. Beale con-
cluded his remarks, which had been listened to throughout with the greatest
interest and attention, amidst a hearty outburst of prolonged applause.

Dr. R. Braithwaite said that he felt he had now a duty to perform, in which
all would join, namely, that of proposing a vote of thanks to Dr. Beale for what
he had brought before them that evening.

Mr. T. C. White seconded the motion, and expressed his personal thanks to
the president for his kindness in coming forward in the way he had done. The
vote of thanks was then put to the meeting and carried by acclamation.

The President having briefly responded, the proceedings terminated with a
conversazione, at which the following objects were exhibited —

A new Selenite Stage exhibited by Mr. Ackland.

Eggs of PI usia Gamma .. .. ... ,, Mr. Brown.

Various Greenhouse Insects ,, Mr. Collins.

Various Foraminifera, from Burn's) Mr. Hailes.

Pool, Gonnemara ..... ) "

Mr. Curteis also exhibited a large series of Mr. Higgin's beautiful Micro-
photographs, a new portable microscope lamp in case was introduced by Mr.
Mogenie, and some specimens of mud from Jamaica was sent for distribution
amongst the members by Mr. Adcock.

E. T. Lewis.

157

Yeast and other Ferments.
By C. A. Watkins.

{Read March 23rd, 1867. j

In this paper I shall endeavour to lay before you some of those
chemical changes which take place in certain substances when under
the influence of other substances called Ferments. In some of
these transformations the microscope shews us that there exists an
intimate connection between the processes and the growth of some
minute organisms, while in others the changes are purely chemical.
The subject, which is of interest alike to the physiologist, micro-
scopist, and chemist, has received great attention from many ex-
cellent observers ; nevertheless, very little is known about it, and
at present the whole matter is involved in great mystery.

I, therefore, feel considerable diffidence in addressing you on such
a subject, and should not have attempted it had I not observed that
many writers fall into serious errors when discussing the chemical
operations of the Ferments.

I may at once tell you that the matter contained in this paper is
perhaps more chemical than microscopical ; but the fact is, these
two investigations are inseparable if we desire accurate knowledge,
and it is impossible to view Ferments broadly, if treated only as a
chemical or only as a microscopical subject.

Fermentation is a term applied to various chemical transforma-
tions, which certain ordinarily stable compounds, such as starch and
sugar, undergo when in contact with a small quantity of an azotised
or albuminous substance, which is itself in an active state of altera-
tion. This active substance is called a Ferment, and one of the
peculiar properties of such a body is that it receives nothing from,
nor imparts anything to, the matter which is undergoing fermenta-
tion, but is itself decomposed and destroyed as a Ferment in pro-
portion to the matter fermented, which is gradually split up, or un-
folded into two or more substances of simpler composition, some-
times with and sometimes without the assimilation of water.

Journ. Q. M. C. No. 13. m

158 0. A. WATKINS ON YEAST AND OTHER FERMENTS.

This unfolding under the action of Ferments is totally different
to that chemical change known as Catalysis, which takes place in
one substance by mere contact with another, such as the unfolding
of Alcohol into Ether, and Water, by contact with Sulphuric Acid ;
for although the acid causes such a wonderful change, it is not
destroyed by the operation, and, consequently, when once the pro-
cess is set going an unlimited quantity of alcohol may be converted
by the original acid.

All the Ferments are highly complex azotised substances allied to
Albumen ; but while they possess this character in common, they
may be divided into two groups — the one being living organisms,
as Yeast, and the other substances derived from various organic
sources, such as Albumen, Gluten, Casein, Diastase, Emulsin, and
a variety of others — all of which decay most rapidly when in a
moist state.

The authors of the " Microscopical Dictionary" would "exclude
these substances from the Ferments, and desire that the term
Fermentation be restricted to those changes which take place only
through the agency of living organisms or Fungi ;" regarding
which, they also, say, *' A general law appears to prevail through-
out the Fungi that their nutrition differs from that of all other
plants in depending exclusively on the absorption and decomposition
(with the evolution of carbonic acid gas) of organic compounds,
therefore consisting of the performance of the operation of
fermentatation on the organic matters on which they feed."
But as the chemical operations of the Ferments are so similar,
notwithstanding the wide difference in their organisation, I consider
there would be no advantage in separating them as proposed, as
they form a distinct class of chemical phenomena. I have also to
observe that it is not true that carbonic acid gas is always given off
during fermentation, nor is it proved that it is evolved during the
growth of all the Fungi. The Ferments to which I desire to call
your attention are —

Mycoderma Vini, or Yeast, which converts Sugar into Alcohol.
Boiled Yeast, which converts Sugar into Gum and Mannite —

this transformation being called the Viscous Fermentation.
Casein, which converts Sugar into Lactic Acid and Butyric

Acid ; this last conversion, however, being attributed to

the action of the Vibrio and Diastase, which converts

starch into sugar.

C. A. WATKINS ON YEAST AND OTHER FERMENTS. 159

I shall have a few words to say on M. Aceti, or the Vinegar
Plant as some call it, which, although included by many among the
Ferments, is not so considered by chemists, for reasons I will here-
after explain.

When a saccharine solution is left in contact with casein either
in the form of fresh curd or cheese, the sugar is slowly transformed
into lactic acid, according to the following equation : — ■-

Cane Sugar CHO + HO = 2CHO Lactic Acid.

12 11 11 6 6 6

In this fermentation water is assimilated, but no gas is evolved.

A solution of lactic acid, similarly treated, is transformed into
Butyric acid thus : —

Butyric Acid. Carb.Acid. Hydrogen.

Lactic Acid 2CHO= CHO + 4CO + 4H

6 6 6 8 8 4 2

In this fermentation, both carbonic acid and hydrogen gases are
evolved. It is a question not yet answered, whether these chemical
changes are induced by mere contact with the decomposing casein
which is regarded as the ferment, or whether the minute organisms
developed in these solutions are the real ferments living on the
matters therein. One thing is quite certain, that in both fermenta-
tions living organisms abound, and they cannot grow without
chemical changes taking place.

" M. Pasteur considers that a specific ferment is concerned in the
production of the lactic acid fermentation, which spreads itself out
as a grey substance over the surface of the sediment ; and he
asserts that this organism when once obtained, and a small quantity
added to a solution of sugar, very rapidly converts it into lactic
acid, provided the solution contain a small quantity of some nitro-
genous substance. When this grey matter is examined by the
microscope it is seen to consist of very small globules or very short
articulations, either isolated or in threads, much smaller than Yeast,
and to exhibit very rapid gyratory motion."

I have not succeeded in obtaining this grey matter, but as the
lactic acid fermentation goes on very slowly, and as this season of
the year is not favourable for experiments on fermentation, it may
not have had time to make its appearance.

In order to observe the organisms which accompany the trans-
formations of sugar, I watched the progress of the lactic acid

m 2

160 C. A. WATKINS ON YEAST AND OTHER FERMENTS.

fermentation of cane sugar, that of milk sugar by the gradual de-
composition of milk, and also the viscous fermentation of cane
sugar ; for although I have seen no notice of any living organism
being concerned in this fermentation, I thought it likely that the
viscid ropy matter which is formed therein was probably due to
some organic growth.

Now in all these experiments I found that as soon as decompo-
sition commenced, or at least was appreciable, but not until then,
organic life was found in all the fluids ; that in all cases they ap-
peared on the surface before they were seen in the body of the fluid,
and that when first discovered they were not in an active condition,
but as the decomposition progressed they became so, and moved
through the fluid with rapidity, but those at the surface continued
to be the most active. These bodies are species of Vibrio and
Bacterium.

The milk used in the experiments was obtained perfectly fresh,
and divided into three portions — one containing the cream after the
milk had stood 24 hours, the second was simply the skimmed milk,
while the third portion was some of the same, with the addition of
chalk to neutralise the lactic acid as it was formed. During four
days the milk remained sweet, and I detected no organism in any
part of it ; but at the end of the fourth day the cream had a sour
odour, indicating that lactic acid had been formed, and a small
speck taken from the surface with a needle exhibited a mass of
Bacterium like bodies which, when some distilled water was passed
between the glass slide and cover, swarmed through the fluid with
rapid and various capers.* On the fifth day the milk had become
sour, and exhibited the same active organs, but in the portion to
which the chalk was added they were neither so numerous nor so
active. On the eighth day fungus spores and mycelia appeared on
the surface of the cream, and the same was noticed, but in a lesser
degree, some days afterwards on the two portions of milk ; but as
a considerable amount of lactic acid was formed before these objects
made their appearance, I do not imagine they were concerned in
the fermentation which was going on.

But it was in the mixture of Boiled Yeast and sugar solution to
produce the viscous fermentation that T found these bodies de-
veloped most rapidly, for in 24 hours after the mixture was made,

* The motion here referred to is not due to the currents produced by capillary
attraction, evaporation, &c.

C. A. WATKINS ON YEAST AND OTHER FERMENTS. 1G1

the fluid was covered with a thin film, which proved to he entirely
these organisms packed closely together, so that no motion could be
seen until some distilled water was added, when their activity was
fully displayed. In the course of a few days the film had become
a thick viscid scum, consisting entirely of these minute bodies
without a sign of any fungoid growth.

From the fact that these organisms grow most rapidly, and are
in the greatest activity at the surface, it appears that air is neces-
sary to produce these results, for in the mixture of milk and chalk
from which carbonic acid was given off as the lactate of lime was
formed, they were always in smaller quantity, and less active con-
dition : this vessel, too, was covered with a plate of glass, while all
the other solutions were covered with paper.

When starch or sugar is transformed* into butyric acid, Vibriones
are sure to be found in the fluid, whether they produce this fermen-
tation or not ; and lately a most remarkable statement has been
published by M. Bechamps regarding this matter. This gentle-
man asserts that he has discovered that there exist at the present
time, in large blocks of chalk taken from a depth of 200 feet from
the surface of the soil from a tunnel driven in a mountain, large
quantities of microscopic animalculas, which he has named Micro-
zyma Cetas ; and he also states that if some of this chalk be placed
in a saccharine solution lactic and butyric acid fermentation
ensue.

Yeast is so well known that its description here is quite unneces-
sary, and the fact that it converts sugar into alcohol is patent to
all. The chemical formula of this change is thus : —

Grape Sugar. Alcohol. Carbonic Acid.

CHO = 2CHO +4CO
12 12 12 4 6 2 2

Yeast is supposed to be the conidial condition of Penicillium
Glaucum, but much light is required to be thrown on this matter to
raise it from its present obscurity.

The yeast cells consist of an outer membrane of cellulin — the

* During the transformations which took place in these experiments, I detected
no organism having the slightest resemblance to Yeast ; the only fungus being
Oidium Lactis, which does not grow in the fluid, and, in my opinion, has no
reference to the fermentation. In all the instances in which lactic acid was
formed, I noticed only Bacteria or Vibriones, and while I admit that under
more favourable conditions of temperature, other growths may appear, I do
not consider any of these organisms to be the specific lactic acid ferment.

162 0. A. WATK1NS ON YEAST AND OTHER FERMENTS.

same material as the cellular tissue of other vegetables— in the
interior of which is a highly complex gelatinous substance allied to

albumen.

The appearance of Yeast under the microscope varies con-
siderably with its condition ; when at rest, that is, when fermenta-
tion is arrested, its form varies from globular to ovoid, frequently
with an uneven outline, as if the cells were very partially empty ;
but when they are put into a fresh solution of sugar they swell out,
and during active fermentation appear globular or nearly so, and
more transparent than before.

When Yeast is added to brewer's wort it increases rapidly, and
grows to six or eight times its original quantity during fermenta-
tion ; the wort being a solution which contains in abundance the
elements required for its development, namely, grape sugar and
some albuminous substances derived from the malt and hops.

During fermentation these albuminous matters disappear from
the solution in proportion to the development of the Yeast, and the
sugar also disappears in the same ratio. When the fermentation
is complete, we find that in place of the complex albuminous
matters in the wort we have simpler chemical combinations, such as
salts of ammonia, and in place of the sugar we have alcohol. These
chemical changes take place simultaneously ; but with this impor-
tant difference, that the amount of nitrogen in the original wort is
reduced by about one-half, while the alcohol and carbonic acid
nearly correspond to the weight of the sugar, the remainder being
converted into lactic acid, &c, a small quantity of which is always
formed during vinous fermentation. But the Yeast consisting
almost entirely of albuminous matters, and having increased to
several times its original quantity, fully accounts for the disappear-
ance of so large a proportion of the nitrogen from the wort.

Thus it will be easily understood, that Yeast, in order to grow,
must be supplied with some soluble azotised matter, such as
albumen ; and it is as easily proved that it will not grow without.

To ferment 100 parts of sugar, one part of yeast is required ;
when the fermentation is complete, the yeast is exhausted, and in
its place ammoniacal salts and cellulin are found. As the vinous
fermentation takes place only during the growth of the yeast, it
may be said that it will grow in simple saccharine solutions. In a
certain sense this is correct, but such growth is degenerate and ex-
haustive, and not the healthy growth which increases and multi-

C. A. WATKINS ON YEAST AND OTHER FERMENTS. 163

plies, for in such a solution the yeast positively lives on its own
substance : this has been proved by Pasteur, in the following
manner : — " He took a quantity of washed yeast, and divided it
into two equal portions, — one of these was placed in a solution of
pure sugar, the other portion was boiled in water, the decoction
filtered, and the filtrate added to a similar solution of sugar, to
which a very minute quantity of fresh yeast was added. In the
first case 12 parts of sugar were converted into alcohol in six days,
when the yeast became exhausted. In the second case the liquid
became turbid ; fresh yeast was formed at the expense of the
azotised matter derived from the boiled yeast, and ten parts of
sugar were fermented in nine days."

Some years ago, when experimenting on bread making, I was
much puzzled by finding that when the yeast was thoroughly
washed the sponge did not rise so quickly, nor was the bread so
light as when made with yeast as received from the brewery. I have
since learned that a portion of the yeast is soluble in water, and that
when it has been dissolved out by washing, the yeast is less active ;
on exposure to the atmosphere, however, it recovers its activity.

Yeast causes a curious and important change to take place when
added to a solution of cane sugar, converting it into fruit sugar by
causing it to combine with one equivalent of water, during which
operation the solution increases in specific gravity. This trans-
formation is attributed to the soluble portion of the yeast ; but be
this as it may, some of it is evidently destroyed by the process, as
a larger proportion of yeast is required to convert cane sugar into
alcohol than grape sugar. It is a fact scarcely known to brewers,
who use it, that cane sugar cannot be fermented into alcohol ; for
although when yeast is added to a cane sugar solution the vinous
fermentation eventually ensues, it nevertheless does not commence
until the yeast, without any apparent change in itself, has transformed
the whole of the cane sugar into fruit sugar. The progress of this
transformation may be witnessed by polarized light : the cane
sugar producing a right hand rotation of the ray=73°, while the
fruit sugar causes a left hand rotation of 26°.

I have one more observation to make in reference to yeast.
When it has been kept some days, of course, according to tempera-
ture, it loses the pleasant smell it had when fresh, and acquires
some fermentive properties, which, as far as I am aware, have not
received much attention. It is well known to brewers that if the
yeast be allowed to stand on the beer for a day or two after fer-

164 C. A. WATKINS ON YEAST AND OTHER FERMENTS.

mentation lias been stopped, a very disagreeable effect is produced ;
the beer is not acetified, but the flavour is entirely changed ; it is
unpalatable, and the brewers call it yeast-bitten.

Now I am not in a position to throw any light on this change ;
but if stale yeast be examined with the microscope, there will be
found interspersed among the ordinary cells a large number of
minute globular bodies, which are generally in motion ; and I have
also noticed a larger proportion of short, straight vibrio-like bodies,
than are to be found in yeast during active fermentation.

Whether these organisms produce the disagreeable effects referred
to, I am unable to say, and merely point to them as one of the
changes which take place in yeast when left to itself.

Diastase is a ferment, which has the property of converting
starch into sugar, by causing it to assimilate the elements of water
without evolving any gaseous products. < N -

The transformation is represented thus : —

Starch. Water. Sugar.

CHO + 2HO = CHO
12 10 10 12 12 12

Diastase is extracted from malt by soaking it in water, in which,
at moderate temperature, it is soluble ; it may be taken as the type
of the ferments produced in all germinating seeds — for as all seeds
contain starch, which must be rendered soluble in the form of sugar
before it can become food for the embryo — so they all contain some
azotised matters as albumen, gluten, &c, which are capable of
passing into the form of a ferment, allied to diastase.

The action of diastase on starch is so well described in all
chemical works — which treat of the vegetable products — that it
seems strange anyone should attribute the conversion of starch into
sugar, during germination, to any other cause, without assigning
some sound reason. Yet, in a popular book by Dr. Carpenter, on
" Vegetable Physiology," published a few years ago, he says : —
" Starch differs but little from sugar, in chemical composition,
except in containing one additional proportion of carbon. When
germination commences, oxygen is absorbed by the seed in the
substance of which it combines with the carbon that is to be set
free from it ; and a large quantity of carbonic acid is then given
forth again to the air, whilst, in the same proportion, the starch is
converted into sugar."

This implies that the conversion of the starch into sugar, and
the evolution of C O 2 gas in germination, are the results of the

C. A. WATKINS ON YEAST AND OTHER FERMENTS. 165

same process ; but if you will refer to my diagram, you will see
that starcli does not contain an additional proportion of carbon, as
compared with sugar, but that it requires two equivalents of H to
equal it ; and that were one or two equivalents of carbon to be
oxidized and abstracted, we should not have sugar as the result.

It is a well-known fact that, in germination, the starch is con-
verted into sugar by the diastase, which is probably formed from
the azotised matters by the vital action of the embryo. The oxida-
tion of some of the carbon contained in the seed is more likely to
be due to the decomposition of the sugar and other matters by the
growth of the embryo, the cells of which appear to me to perform
chemical functions similar to some of the fungi, for at this period
of its growth it must be remembered the vegetable action is
reversed, that it is now living on organic compounds and evolving
C O 2 gas; whereas, when it has expanded its leaves to the light
and atmosphere, its food must be reduced to simpler forms before
it can assimilate it, and it will then construct organic compounds,
and decompose C O 2 gas, eliminating oxygen.

Malt contains about -3-L- part of its weight of diastase, and as
one part of diastase will convert 2,000 parts of starch into sugar,
it evidently contains a much larger quantity than is necessary for
the conversion of the remaining starch in the grain. This is taken
advantage of in various ways by distillers, &c, for the purpose of
converting unmalted grain and starch from other sources into sugar.

The action of diastase and other similar soluble ferments is sup-
posed to be instantaneous when the matters on which they act are
also made soluble.

As an illustration of this, I will tell you what is done at one of
the large distilleries in the North.

Starch and grain are ground into a fine powder, and put into a
mash tun capable of holding several hundred quarters, and heated
till the starch granules burst, and a thick paste is formed. When
at the proper temperature, an infusion of malt is run in and agitated,
and in about two minutes the whole of this stiff mass becomes per-
fectly fluid, the starch being at once converted into sugar by the
diastase in the infusion*

In the instances of fermentation I have brought to your notice,
I have shewn only the chemical transformations of the matters
fermented, these changes resulting in the re- arrangement of the
atoms or the molecules of which those matters are built up, thereby
giving rise to entirely new structures.

166 C. A. WATKINS ON YEAST AND OTHER FERMENTS.

The ferments themselves suffer differently, being always reduced
to the simplest combinations.

Looking at the result of a fermentation, it would appear that the
ferment and the matter fermented did not enter into combination,
but that its transformation is due to the force generated in the
decomposition of the ferment with which it is in contact. It is,
however, clear that the changes which take place in the two sub-
stances are collateral, for the same ferment will produce various
chemical transformations of a substance according to the phase of
its own decomposition. " Thus diastase, when fresh, converts
starch into sugar ; if kept for a few days, it converts it into gum
instead of sugar ; while at another period it converts the starch
first into sugar, and then transforms it into lactic acid."

Therefore the transformations always depend on, and are relative
to, the peculiar changes which take place in the ferment.

The commercial production of vinegar appears to be due to the
agency of one or more microscopic organisms, the mass being called
the vinegar plant, which, as I have said, is not regarded as a true
ferment by chemists, and for this reason ; all the ferments proper,
such as I have described, produce the transformations entirely
within the solutions, receiving nothing from, nor imparting any-
thing thereto ; but the conversion of alcohol into vinegar is a case
of simple oxydation, in which the oxygen is derived from the
atmosphere, each equivalent of alcohol absorbing four equivalents of
oxygen to become acetic acid, according to the following formula :

Alchol. Aldehyd. Water.

CHO + 20 = CHO + 2HO

4 6 2 4 4 2

Aldehyd. Acetic Acid.

CHO + 20 = CHO+ HO

4 4 2 4 3 3

In countries where no duty is imposed on the manufacture of
alcohol, it can be made into vinegar cheaply and rapidly. The
alcohol diluted with water, and a small quantity of some azotised
substance added, is allowed to trickle over beech shavings placed in
a vat, so arranged, that a current of air circulates freely through-
out.

For some days the process goes on very slowly ; but the shavings
become gradually covered with a slimy fungus, called mother of
vinegar, and then acetification proceeds much more rapidly.

Pure dilute alcohol, exposed to the air, undergoes no chemical
change ; and its conversion into vinegar is undoubtedly due to some

C. A. WATKINS ON YEAST AND OTHER FERMENTS. 167

complex action of the growth of the fungus on the matters in solu-
tion ; but the exact chemical operations of this vegetation are
unknown.

Since writing the above, my attention has been called to some
observations on this plant by Mr. Slack, (Vol. V., p 2), and pub-
lished in the " Microscopical Transactions." He states — and I have
no doubt of the truth of the assertion — that, " If some of the
gelatinous portion of the plant be examined with high powers, it
will be found to contain millions of minute bodies, resembling
bacteria, some of them not exceding 16 o 00 of an inch in length.

I have recently examined a dilute solution of alcohol, which is
being converted into vinegar, and find these bacteria in abundance.
They may be seen distinctly when magnified 250 diameters, though
a high power must be used to resolve their structure.

The study of these minute organisms, though very uninviting to
the general microscopist, would richly reward any patient investi-
gator — for until we know more of the chemical processes which
take place in and through them, the subject of putrefactive decom-
position must remain a blank, as it is at present.

The vinegar plant and yeast are said to be different conditions
of the same vegetation ; the Brothers Tulasne have shewn us that
these lower species of vegetation pass through various phases during
their growth, each having previously been considered as a distinct
plant ; and I see no reason why these minute organisms should not
produce different chemical combinations at the different stages of
their development, since we see, in the higher order of certain
plants, that some of their chemical processes are reversed at
points of their existence, namely, during germination, flowering,
and the ripening of the fruit, when they absorb oxygen and give
off carbonic acid to the atmosphere.

In conclusion, allow me to observe, that I am fully aware of
having written a paper with a very slender knowledge of the micro-
scopic organisms, whose chemical operations I have discussed;
therefore, I hope those parts which I have left in darkness will
now receive the light of your experience and knowledge as micro -
scopists. I am very anxious to obtain information concerning the
part which those minute vibriones and bacteria play in nature's
economy, for there can be no doubt that those remarkable bodies,
appearing everywhere, and springing into active existence almost
at a moment's notice, must perform some important part in many
of the changes which surround us.

168

DlATOMACEOUS DEPOSITS FROM JUTLAND.

(Part 2.)
By F. Kitton.

{Read January 21th, 1871.)

In a previous communication, read before the Club on the 24th
June last, and published at page 99 of the present volume of the
Journal, I enumerated and gave descriptions of a series of forms
occurring in these deposits, chiefly those described, or referred to
by Heiberg. There remain other forms to be named and described,
some of them new, and all interesting, which form the subject of
the present paper. Some apology, perhaps, is needed for offering
so purely technical a communication to the Club, but the barren
facts of science are essentials, without which there could be no
generaliz ations .

1. Stictodiscus angulatus (Grunow) — Frustules composed of two
dissimilar valves, one convex, the other slightly concave and um-
bonate ; valves disciform, the convex valve with two slight mar-
ginal projections at the opposite diameters ; markings cellulate and
costate; costae conspicuous near the margin, but disappearing as
they approach the centre cellules; radiant between the costa3 ; scat-
tered at the centre ; concave valve without marginal inflations ;
costae indistinct or wanting ; cellules more scattered ; centre with
distinct pore, or pseudo-nodule ; frequent in the Mors, Fuur and
Nykjobing deposits (pi. 13, figs. 1-2).

This elegant little form resembles S. Kittonianus (Greville), but
differs from that species in the peculiar lip-like projections of the
convex valve. The concave valve resembles Porodiscus nitidus, of
Grev. Trans. Mic. Soc, vol. xi., p. 65, pi. 4, fig. 5, and it is
probable the two forms are identical. I have named this species,
on the authority of Moller's, " Typen Platte."

2. Aulucodiscus Jutlandicus (n. sp., F.K.) — Valve hyaline; pro-
cesses sub-marginal ; furrows distinct ; granules radiant ; disc not
bullate, beneath the processes ; deposit Fuur (pi. 13, fig. 3).

F. E.ITTON ON DIATOMACEODS DEPOSITS FROM JUTLAND. 169

This species has not, so far as I am aware, been found in any
other deposit than that from Fuur. I am indebted to G. M.
Browne, Esq., of Liverpool, for the loan of this species.

3. Stephanogonia Danica (Grunow) — Valve in front view pro-
duced to a long blunt point ; side view discoid, with six or more
rays ; centre hyaline ; spaces between them marked by irregular,
anastomosing lines ; surface granulate, or rugose ; common in the
Mors, Fuur, and Nykjobing deposit (pi. 13, figs. 4-5).

I have adopted Herr Grunow's generic and specific names on
the authority of the Typen Platte. Although common, I have not
been fortunate enough to detect a perfect frustule, and am unable
to tell whether the valves are similar. The probability is that they
are so, as no valve occurs in these deposits, differing from the one
now described, that can be referred to this species. The elegant
outline of front view of valve forcibly reminds of the tapering
dome of a Turkish minaret.

4. Trinacria Heibergii (n. sp., F.K.) — Frustules in series ; pro-
cesses produced ; margin of valve convex, turgid, extending beyond
surface of valve ; central portion of valve umbonate; base of mar-
gin with conspicuous, moniliform granules, arranged in series, but
becoming scattered and distant as they approach the upper portion ;
surface of valves marked with small granules, arranged in radiant,
curved lines, indistinct or absent as they approach the centre (pi.
13, fig. 6). Mors deposit.

Vai" margin as in preceding form; surface of valve hyaline,
smooth, or with few scattered granules (pi. 13, fig. 7). Mors
deposit.

The very singular species I have above described is not uncom-
mon in this material, and I was long inclined to consider it a form
of T. regina, but the plumose arrangement of the granules, and their
small size, and the projecting margins, seem to warrant a separa-
tion from that species. The variety with upper surface smooth
might easily be mistaken for the marginal part only, but careful
focussing will detect the presence of a thin hyaline surface, some-
times marked with a few scattered granules.

5. Triceratium maculatum (n. sp., F.K.) — Valve with slightly con-
cave margin ; granules small and close at the centre, larger and
scattered as they approach the sides ; margin with short, conspic-
uous costas ; centre of valve with three or more irregular, radiating
lines ; deposit Nvkjobing (pi. 14, fig. 14).

170 F. KITTON ON DIATOMACEOUS DEPOSITS FROM JUTLAND.

This diatom occurs in the Nykjobing deposit only, it resembles
T. venulosum, of Greville, in Trans. Mic. Soc, but on careful com-
parison it will be found to possess many well marked differences.

Trochosira (nov. gen., F.K.) — From T/so^o?,awheel, and ^eipa,
a chain. Frustules in filaments connected by one or more central
processes ; valves discoid, convex, smooth, or faintly striate margins.

6. T. mirabilis (n. sp., F.K.) — Frustules connected by along spine
produced from the centre of the valve ; valves in front view smooth,
with a central nodule (base of spine) pi. 14, figs. 8-9, Mors, Nyk-
jobing, and Fuur deposits.

This very singular form requires to be seen in a living state to
fully understand its structure. The space between the two oppos-
ing valves, and perhaps the whole of the frustule, was covered
with a non siliceous investing membrane.

7. T. spinosus (n. sp., F.K.) — Frustules in filaments connected
by five or more short processes ; valves in front view convex ;
central portion flat or truncate (a section of valve resembles a short
truncated cone), the spines produced from the margin of the central
portion ; side view of valve discoid, five or more sub-central nodules
(bases of spines), margin faintly marked with short strias (pi. 14,
figs. 6-7), associated with the preceding.

8. Sceptroneis gemmata (Grunow) — Frustules bacillar ; margin
with distinct, pearl-like granules connecting zone ; finely punctate ;
puncta arranged in longitudinal lines ; valve narrow, gradually
tapering to the narrow, rounded apices ; costate costal broad,
nearly reaching the centre of valve (pi. 14, figs. 4-5), common in
the preceding deposits.

I have named this species on the authority of the Typen Platte ; it
resembles S. caduceus, of Ehr., in its markings, but differs much in
the outline of side view. I have seen it forming a short series of
five or six frustules.

The forms described and figured in this and the preceding paper
are characteristic of these deposits ; many other species occur in more
or less abundance, most of which have been described and figured
by various observers as occurring in various fossil deposits or recent
material.

F. KITTON ON DIATOMACEOUS DEPOSITS FROM JUTLAND. 171

The following is a list of the most prevalent : —

Stephanopyxis (Creswellia) sp.? (p. 14, fig. 15).
Coscinodiscus stellatus*
„ radiatus

j, Oculus Iridis

„ concinnus ?

Actinocyclus Ralfsii, rare
Actinoptychus senarius.
Goniothecium?? (pi. 14, figs. 1-2-3).
Syringidium ? ? (pi. 14, fig. 10).
Hemianlus?? pi. 14, fig. 11).
The three last-named forms I do not describe, and refer them to
the respective genera with great doubt ; figs. 12-13, pi. 14, is
probably not diatomaceous ; it is, however, so remarkable I thought
a fig. of it might be desirable.

The Protozoa are represented by two or three species of Poly-
cystina ; and sponge spicules.

EXPLANATION OF PLATES.

PLATE 13.

1. Stictodiscus angulatus S.V.

2. Stictodiscus angulatus F.V.

3. Aulucodiscus Jutlandicus.

4. Stephanogonia Danica S.V.

5. Stephanogonia Danica F.V.

6. Trinacria Heibergii.

7. Trinacria Heibergii var. _

8. Trinacria Heibergii, section of valve.

PLATE 14.

1. Goniothecium ? ?

2. Goniothecium ? ?

3. Goniothecium ? ?

4. Sceptroneis gemmata E.V.

5. Sceptroneis gemmata S.V.

6. Trochosira spiuosus F.V.

7. Trochosira spinosus S.V.

8. Trochosira mirabilis F.V.

9. Trochosira mirabilis S.V.

10. Syringidium ? ?

11. Hemiaulus? ?

12. Undescribed form (not diatomaceous?)

13. Side view of ditto.

14. Triceratium maculatum.

15. Creswellia sp. ?

X 400 diameters.

* According to the Typen Platte, this is the Symbolophora Trinitatis of the
Microgeologie, an opinion with which I do not concur.

172

Sections op Hard Tissues.
By T. C. White, F.R.M.S.,

{Read December 23rd, 1870.)

One of the easiest preparations that young microscopists can try their
u 'prentice hand " on is the making of sections of the hard tissues, and
it is one attended with much interest in watching the gradual de-
velopment of structure where all was dark and opaque before. It is
not my intention this evening to dwell upon making sections of such
tissues as wood, horn, or hair, and such like structures, but to speak
more upon the making of sections of teeth for microscopic examina-
tion, as the mode generally adopted in this case is applicable to
such substances as shell of various kinds, and such hard tissues as
stones of the plum and peach, &c. It has been recommended by
writers on this subject that the section after having been cut by a
fine saw and reduced by a file, should be further rubbed down on a
hone, this plan has been attended with very good results in the
hands of some, but I wish to bring before the members this evening
the plan I have adopted for some time, and which I am rather
favourably inclined to. I proceed in the ordinary way to make a
thin section by means of the saw and file, reducing my section to
the thinness of an ordinary card, then, instead of using a hone,
which I find rather a slow process, I place my section between two
plates of ground glass, with plenty of water, and by rotating the
upper glass upon the second, I succeed in getting the finest and most
transparent sections. After using these plates some time the grain
of the glass gets worn away, and thus, if you keep your glasses, you
may get every degree of coarseness required, the oldest pieces put-
ting a final polishing to your section. If you desire to expedite the
first part of the grinding, a little finely powdered pumice stone
sprinkled between the plates will greatly assist the rapidity of the
action of the glass, especially in cutting such tough shells as that
of the crab and lobster. I have placed under the microscope this
evening the lower jaw of a weasel cut in this manner, and still

T. C. WHITE ON SECTIONS OF HARD TISSUES. 173

retaining its teeth. In this case I soaked the jaw in snch a way as to
saturate it with Canada Balsam in Benzole ; this, when it had evapo-
rated, filled every interstice with hard balsam, and so retained the
teeth in position while the grinding was performed.

I wish now to speak of the various appearances observed in sec-
tions of the teeth, as it may prove useful to many here who may
feel inclined to make sections of some sent here for distribution this
evening.

The tooth most easily worked is that removed from a child, a
temporary tooth ; the structure approaches most nearly to the normal
condition, and such a section will present the following appearance :
in the centre, a cavity occupied in the recent state by a soft fleshy
mass — what is popularly known as the nerve, but in reality being
composed of the minute ramifications of the nerve, vein, and artery,
supported by fibrous tissue ; on the outer side of this, and making
up the greater part of the tooth, is the dentine, or the tooth bone
proper, as it may be termed ; this consists of a number of fine tubes,
about l0 -* 00 of an inch in diameter placed closely side by side, and
radiating everywhere at right angles to the walls of the central pulp
cavity. Covering the upper part as a protection, may be seen the
dense, almost inorganic enamel, whose crystalline prisms stand
vertically to the surface of the dentine, and covering that part of
the tooth which protrudes through the gum. On the lower part of
the fang, and thickest near the apex of the root, the cementum will
be found with its lacunae and straggling canaliculi. Such, roughly,
is a sketch of the appearance presented in a healthy, well-developed
tooth ; but age and various disturbing causes will interfere "with or
alter the appearance here described, and I shall now attempt to give
you a description of the changes from the normal condition which are
usually met with.

Some teeth are obliged to be removed, especially in old age, on
account of getting loose and barely hanging in the mouth; these teeth
seldom show any decided appearance of decay, and are generally
extracted entire.

Upon making a section of such a tooth as this, the apex of the
tooth will be found transparent like horn or tortoiseshell ; such teeth
are to all intents and purposes dead members, and hence the loosen-
ing. The dentinal tubes are filled up, and become consolidated by a
deposition of calcareous matter, and should the tooth be ground
down on its surface by mastication, the upper part of the pulp

Journ. Q. M. C. No. 14. n

I

174 T. C. WHITE ON SECTIONS OF HARD TISSUES.

cavity will be found filled with a secondary dentine, presenting some
resemblance to the regular dentine, but with the tubes more sparsely
distributed, and curving irregularly through the mass.

In fangs of teeth that have been painful for some time, attended
by much inflammatory action, fresh bone is added to the cementum,
and what is termed an " exostosis " is produced; such a one as this I
have placed under the microscope, where the layers may be observed
succeeding each other in the order of the inflammatory exacerbations.

In some teeth presenting a rough, ridgy, and honey-combed
appearance, the dentinal tubuli are found traversing large globules
of the dentine, as if originally the dentine had been put together in
large globules which had never become fused, but had left inter-
spaces between each globule. This form of dentine is generally found
in teeth of delicate children where some illness has interfered with
the process of deposition, and hence the imperfect calcification.
These teeth are best mounted by laying the section on a tolerably
stiff layer of balsam, and when thoroughly embedded in it, cover it
with balsam almost as stiff as that placed under it, that no absorp-
tion may take place which would render the interspaces too trans-
parent and invisible.

On Papers for the Club.
(Read August 26th, 1870.)

In looking over the past records of the Quekett Microscopical
Club nothing has so often forced itself upon my attention as the
note " Papers Wanted," and no greater difficulty presents itself
now than that want of papers " on topics of interest, that discussion
of doubtful points," which will be found enumerated as among the
objects for which the Club was founded. From whence, then,
arises this want ? How shall this difficulty be surmounted ?

First, I would ask, why do members hold back their communi-
cations ? For all must have some they could make. What do they
consider is required of them ? And here let me say I believe we strike
at the fountain head of all that reticence so marked of late at our
meetings. I believe the feeling, if not openly expressed, is at least
tacitly felt, that the Quekett Microscopical Club is a scientific
society, and accordingly that communications made to it must

T. C. WHITE ON PAPERS FOR THE CLUB. 175

possess that startling and novel character which mark the papers
read at societies whose aims are the elucidation of deeper mys-
teries of natural science than come within the scope of microscopy.
Now here, I conceive, the root of the difficulty lies, a root spring-
ing up into that gloomy shadow obliterating the " cheerful con-
verse" which should characterise the meetings of men whose tastes
and pursuits are of a kindred nature.

Allow me then, in the first place, to assert, on behalf of the
founders of the Club, that it never was their intention to aim at
being a scientific society, or to place the Quekett Microscopical
Club on the same level as that occupied by the scientific societies
of Great Britain ; it was founded for a different purpose, and was
based more upon the social assistance it renders in working out all
that appertains to the microscope than the scientific work it accom-
plishes. Let members, then, disabuse their minds of this lofty
imagination, if they harbour it ; let them content themselves with
the practical, social, and valuable work they have performed and
are destined still to perform, and not be like Icarus of old, who,
soaring too high, melted the wax of his wings, and ended in an
ignominious and fatal descent.

Now, what is the nature of the papers required ? 1st, they
need not be long. We are all, I suppose, men of business,
aad not men of leisure ; and, therefore, it would of necessity
be an obstacle of considerable importance were we required to
fill up the time of the Club by the reading of a paper of half-an-
hour's duration. If a man has a subject at his finger's end he can
easily throw it together in a short and condensed form, without
sacrificing its integrity, therefore I would advocate short papers.
2nd, What should be their subjects ? And here we enter upon a
wide field, for it embraces nearly the whole realm of nature ; but
there are without doubt in the Club men who have worked in each
or all of these departments, and who are competent to tell us of the
results of their enquiries in these several departments ; they may
not be able to tell us any startling facts, but on the other hand, the
probability is that they could acquaint us with a great deal that we
were not aware of, or at least they could corroborate the investiga-
tions of others. And here I would urge upon the attention of the
members the value of systematic work. The path of the microscopist
lies through a vast plain of interesting facts, but the temptation
besets him at every step to turn aside from the straight path to

n 2

176 T. C. WHITE ON PAPERS FOR THE CLUB.

cull objects of beauty or of interest, which often lead him so far
from the path that he loses himself in the bewilderments of desul-
tory collection and dilettanteism. If this should be the ending, the
wondrous perfection of our instruments is wasted — one might al-
most say prostituted — and they become as expensive but worthless
toys. Such work can leave a world no better than it found it. A
life spent in such pursuits cannot leave its mark behind it ; it is
the style of the butterfly, not of the bee. I would suggest, there-
fore, that each member, according to his taste, should select one or
two subjects for especial investigation ; let him truthfully and im-
partially follow it out, carefully recording every change, and if pos-
sible making faithful drawings of every change. The collecting of
a cabinet of slides is only of secondary importance to a faithful
drawing from a recent specimen, for slides, mount them as you will,
must undergo change, and that change, however slight, detracts
from the truth of the subject ; and who shall say how important a
clue we may lose in unravelling the delicate life history of a tissue,
for instance, by reason of contraction or expansion, by coagulation
or dissolution in the media employed to mount it. Work under-
taken in this manner, would do more in a short time to
advance the position of the Club than any inflated notions
or wishes to rank as a scientific society, if such are enter-
tained. We have the reputation of being a hard working and
practical society ; let us add to this a systematic course of work,
and then, if the departed spirits take an interest in things on earth,
there is one who will rejoice in the army that is named after him.
How, what form should the papers assume ? Their style need not be
laborious, but a plain, simple statement of facts, taking care that
any doubts in the writer's mind are freely confessed, for by this
means discussion will be provoked, and the contact of minds will do
much to elicit the truth by the thorough ventilation the subject will
undergo. Papers such as these will always be welcome, not that
papers full of laborious and exhaustive research would be excluded.
These would be the exception, and not the rule. Ask the
authors of those exhaustive treatises that we have had read
here, and they will bear out my assertion that they were not their
first productions. Such a paper as " The Geographical Distri-
bution of Mosses," or that on " Microscopic Moulds," and others
read here,' were the results of long and systematic work; yet one
of those gentlemen, in the earlier days of the Club, gave a simple

T. C. WHITE ON PAPERS FOR THE CLUB. 177

paper, entitled " Work for the Microscope;" other papers I find
recorded, such as " Manipulation with Canada Balsam," and such
papers now would be most acceptable, giving the author's own ex-
perience of the use of the various mounting media and methods of
mounting, with all his difficulties and failures, openly, plainly, fear-
lessly confessed.

Again, I would suggest that much remains to be worked out
in special departments of microscopical science, and materials for
very valuable papers may be gathered from the study of microscopic
comparative anatomy, by which I mean that a comparison of the
same organ in various insects would prove highly interesting and
instructive. Taking, for instance, the rectal papillae of the blow fly,
it would be very interesting to follow out the rectal papillae in
other insects, and to illustrate the subject by drawings and prepar-
ations. Again, the development of insects, the metamorphoses they
undergo in their earlier stages of growth ; but I need not enumer-
ate the many ways in which systematic work of that kind might be
carried out. A fresh fact in Physiology, well substantiated, will
leave its mark behind. Observations the most simple, if authentic,
will add another brick to that beautiful edifice of truth which honest
observers are combined to erect.

Again, I would add a word of encouragement to the younger
members among us. Do not think because you are young and in-
experienced that if you speak up at our meetings you will be
" snubbed." No such thing. The men who form the Quekett
Microscopical Club are not made of such stuff as would snub a
younger brother. I can answer for that from my own personal
experience; and your very questions would draw out valuable in-
formation from others — information that could not be embodied in
a paper, and which would be welcome to many amongst us.

Then, again, I would suggest to absent members the desirability
of their contributing to the information of the Club. A large pro-
portion of our members are resident in the country ; they doubtless
have many opportunities for systematic work. Many, probably, have
made some special branch of microscopic science their study. If
they will throw the results of their observations together in a paper,
the Committee will gladly accept and take charge of their contri-
butions.

178

PROCEEDINGS.

December 23rd, 1870 — Chairman, Dr. Lionel S. Beale, F.R.S.

President.

The following donations to the Club were announced :• —

" Land and Water" (weekly) from the Editor.

the Publisher.

Mr. Bennett.
Mr.M. C.Cooke.
Mr. Jackson.

" The Monthly Microscopical Journal"
<c Science Gossip,"

X ollQO ... . • . . * . ...

50 Slides . . ... ... ... •»

— OilUL'S * * ... ••• ••• •••

The thanks of the Club were returned to the donors.

The following gentlemen wereballotted for and duly elected members of the
Club :— Mr. Eobert William Atkinson, Mr. John Childers Crisp, Mr. George
M. Dawson, Mr. William Alfred Duck, Mr. John Charles Goldsmith, Mr.
Edward Histed, .Mr. Eobert King, Dr. G. W. Royston Pigott, M.A., and Mr.
Joseph Alfred Smith.

Mr. T. C. White read a paper upon "Making Sections of Hard Tissues."
The thanks of the Club were unanimously offered to Mr. White for his paper.
Mr. James Smith inquired whether Mr. White obtained the sections suffi-
ciently fine to enable them to be mounted without polishing, also whether the
sections were ground on both sides at once.

Mr. White said, in reply, that he placed the sections loose between the plates
of ground glass, and both sides were ground at the same time ; by using plates
of glass which had been much worn, a beautiful polish could be given to the
sections, which could be transferred to a slide and mounted in Canada balsam.
If, however, the balsam was too hot there was great danger of the specimen
being cracked by the heat.

Dr. Lionel Beale said that Mr. White's process was certainly a great im-
provement upon the ordinary method of making sections of bone and other hard
tissues. He could recollect the time when sections used to be ground down
upon the slate, and the finger was employed for the purpose of holding the
specimen. When a portion of the cuticle had been ground away your own
sensations told you that the process was completed. There was one part of the
plan, besides that which had been mentioned, which needed to be considered ;
for, in addition to ascertaining the character of the hard texture, it was very
desirable to find out also the anatomy of the soft tissues which were found
immediately in contact with the hard structure. To prepare sections which
would properly show both together was a problem of some difficulty, but it

179

might be done. The ordinary process of grinding was no doubt necessary for
obtaining sections of considerable extent, but it was not adapted for making
sections of the soft tissues in contact with the hard j as, for instance, of the
soft dentinal pulp as well as of the hard dentine in contact with it. By the
ordinary method the grinding either entirely destroys or obliterates the struc-
ture of the soft pulp, so that it is found that a section of the pulp, with the
dentine in contact with it, as in the recent state, cannot be made successfully
in that way. It was not, however, generally known that these hard textures
might be softened by soaking them for a long time in glycerine ; bone could be
softened by soaking it in glycerine for twelve months, and to such an extent
that it could be cut with a sharp knife with the greatest ease, so that sections
could thus be obtained sufficiently thin to be examined with a l-25th inch
objective, and under this power much more could be learned with regard to the
minute structure of such specimens than under a lower power. In the case of
the stones of fruits, in order to make out their structure it was absolutely neces-
sary to obtain sections in the recent state, and these must be cut and not
obtained by grinding, which would cause the complete destruction of the
texture, if it was in a growing and imperfectly formed state. Another mode of
great practical utility in investigating the structure of hard textures is to
soften them by soaking in glycerine, to which has been added some substance
which will act as a solvent of the hard portions of the tissue. By adding a little
hydrochloric acid to the glycerine (four or five drops to the ounce) bone could
be very readily softened, and by prolonging the action it became possible to
make out exactly the order in which the calcareous matter had been deposited.
When a small quantity of the calcareous matter had been dissolved away, you
could cut thin sections with a knife without difficulty. Acetic acid was also a
valuable agent for this purpose. If it was desired to examine the nerve fibres
in hard tissues, such as teeth, in which they would be completely destroyed by
the ordinary method of investigation, this process might be adopted with
advantage. If soaked for some time in a mixture of glycerine and acetic acid
it would be found that the acid would soften the hard texture, whilst the
glycerine would preserve the nerve fibres intact, and sections could be cut with
a sharp knife with facility, and in any direction that was desired. These were
some little practical points which he had found useful in making thin sections
of hard tissues. Those who attempted these methods must be content with
sections of small extent only, as large ones could not be nicely cut with a knife .
This, however, was a matter of not very much importance, because if a person
made out what might be termed the geography of a large specimen obtained in
the way recommended by Mr. White, he could easily make out the minute
structure by means of small sections cut in the manner described. As a study
for young microscopists, there could hardly be one more interesting than that
of the development of the hard stones of fruit, or the hard shell of a nut, or a
walnut. Mr Quekett and others had perhaps ascertained all that was to be
demonstrated coucerning the structure of the dried fully formed shells which
had been ground down to thin sections, but a vast deal had yet to be learned as
to the manner in which those hard tissues were formed during development.
He was quite sure that a great deal might be done in this branch of investi-
gation, and he strongly recommended the subject to the attention of members
of the Club.

Mr. White said that he could fully corroborate all that Dr. Beale had said.
After using glycerine and acetic acid, as recommended, the tooth became so

180

soft that a section could be cut off quite through the fang, and showing the
dentinal tubes perfectly. He had been working at the subject for a long time,
and had frequently rendered a recent tooth so soft by soaking it in glycerine
and acetic acid, that he could shave off a thin slice with a penknife, and in
some cases the tooth was rendered so soft that he could draw out the contents
of the dentinal tubes attached to the pulp or nerve of the tooth.

Mr. Ruffle said that if any gentleman wished to have some teeth to experi-
ment upon, he could supply them, as a quantity had been placed in his handa
for distribution.

The Secretary read a letter describing a new slide for opaque objects. The
slide was made of wood, with a cell sunk in the centre, over which a cap of
copper tightly fitted, covering in the object effectually from dust, &c, when
not required for use, and enabling it to be seen without a covering glass when
the cap was removed. Specimens of these slides were placed upon the table
for examination.

The proceedings terminated with a converzazione, at which the following
objects were exhibited ; — ■

Transverse Section of Beech by Mr. M. Burgess.

Pygidium of Chrysopa perla by Mr. Conder.

Gemmae of Blasia pusilla by Mr. Jackson.

Section of Lower Maxilla of Weasel ... by Mr. T. Charters White.
A quantity of miscellaneous objects, unmounted, were presented for distii-
bution amongst the members by Mr. D. E. Goddard and oJier friends.

re")

rfrom the Author.

January 27th, 1871. — Chairman, Dr.R. Braithwaite, F.L.S.,&c,

Vice President.

The following donations were announced: —

"Land and Water" (Weekly) from the Editor.

" The Monthly Microscopical Journal" „ the Publisher.

"Science Gossip" ... ... ... ... ... ... ,, »

" The Popular Science Review " ... ... „ ,,

" The American Naturalist" in exchange.

Mr. Mclntire's paper, "Notes on the Minute Structure"

of Insect Scales" (2 copies) ..

A paper "On the discrimination of Fibres in Mixed") -^r -m- m g u ff Ur

Fabrics," by Mr. John Spiller J

6 Slides of Diatoms Mr. Curteis.

18 Slides of Diatomacese Mr. Hardman.

3 Slides of Funaria hygrometrica ... ... ... Mr. A. Smith.

The thanks of the Club were voted to the donors.

The following gentlemen were ballotted for and duly elected members of the
club :— Mr. Thomas Forshaw, jun., Mr. Augustus De Souza Guimaraens, Mr.
Henry Jefferson, Mr. William B. Kesteven, F.R.CS.

Mr. M. C. Cooke read a paper by Mr. F. Kitton, of Norwich, entitled IC A
Further Examination of the Jutland Deposit of the Island of Mors."

The Chairman said he felt sure that all would join with him in a cordial vote
of thauks to Mr. Kitton for his interesting paper j they would also doubtless

181

feel much satisfaction on hearing that a diminution of species was aimed at
rather than an increase in them. Not only in this instance, but also in biology,
botany, and other branches of science, the multiplication of species had become
very inconvenient, every little variety was now called a species, which not only
greatly increased the number of names which had to be remembered, but also
added much to the difficulties of classification. Great service might be done to
science by reducing the number of synonyms, &c, bringing them down to their
regular types. A vote of thanks to Mr. Kitton for his communication waa
carried unanimously.

The Secretary, after calling attention to the subjects of papers announced for
the next meeting, observed that few fields of research were more interesting
than micro-entomology, and suggested the study of the anatomy of the spider aa
affording abundant scope for the researches of any members who desired to
enter into a subject which could not fail to be both useful to themselves and to
science, as very much had yet to be learnt concerning these creatures.

Mr. M. C. Cooke said that some time ago he was on a visit to a medical friend
of his, and then enjoyed two or three hunting expeditions after spiders. His
friend took very great interest in tbem, although he had not done much that
season, because there was nobody else to go with; he was, however, remarkably
expert at catching them, and taught him very soon how to catch them quickly.
His attention had been chiefly directed to the palpi, and of these he had a large
collection of mounted slides ; and as he was mounting a set of them he inti-
mated that if the Quekett Club would accept them he should be happy to
present them to the cabinet. Any doubts on that point were at once
removed, so that before long members would probably have an opportunity of
examining this collection for themselves. Most of the members were probably
aware that the palpi of the female spiders were of small size and were very
much alike, but those of the males were much larger, and differed very con-
siderably, not only in different genera of spiders, but also in the different species
of the same genus. This was so marked that the specific characters of spiders
were greatly strengthened by comparing the difference in the palpi of the male
insects, and persons who were well acquainted with the subject could even de-
cide to what species a spider belonged by merely examining the palpi alone. The
way in which his friend mounted the palpi was very simple • after taking them
off, they were soaked for a short time in liquor potassae, then they were washed
to clear them from the alkali, and were afterwards placed upon a glass slide and
flattened out by pressure. It might be objected to this method that it did not
exhibit them naturally as in the living state; certainly it did not, but they were
extended and spread out by the pressure in a manner which enabled them to be
very readily examined in all parts. The method adopted in hunting for the
spiders was by turning over stones, bricks, tiles, &c, and there was hardly one
beneath which a spider was not found. His friend was provided with a number
of pill-boxes, and when he catches a spider it is immediately popped into one
of them, and then he afterwards chloroformed and dissected them.

The Chairman said he was very glad to have the opportunity of congratulat-
ing the members of the club on the promise of this collection of the most won-,
derful parts of a spider ; he had often, even when a boy, been struck with their
curious nature, and it was now known that they took an important part in the
sexual process. To those members who were desirous of studying the subject,
he would recommend BlackwalFs work on spiders as being the one in which*
they would find the fullest information.

182

The Secretary reminded the members that Blackwell's splendid Monograph
on Spiders, to which Dr. Braithwaite had referred, was in the library of the
Club.

Mr. Guyton exhibited and described a new portable microscope lamp, which
had recently been brought out by Mr. Fiddian ; it was ingeniously contrived to
pack into a brass case, whieh also formed its stand when in use ; he also showed
one of Mr. Field's new dissecting microscopes, which had on a previous occasion
been described to the members.

Mr. J. Michels introduced to the notice of the members of the Club a cheap,
light, and portable stand and body, to which any ordinary eye-piece and objec"
tive could be readily fixed. The body —which was of pasteboard, having a brass
nosepiece at the end, screwed with the Society's thread— was attached to a tripod
mahogany stand, the whole weighing only a few ounces, and costing not more
than seven shillings. He had designed it thinking that something of the kind
was required to obviate the necessity for bringing heavy instruments to the
Club when anything had to be exhibited.

The proceedings terminated with a conversazione, at which, in addition to
the microscopes, &c, above described, the following objects were exhibited: —

Spiracle of Dytiscus By Mr. J. Michels.

Pollen of Cobea scandens By Mr. Conder.

February 24th, 1871 — Chairman, Dr. Lionel S. Beale,

F.R.S., &o.

The following donations were announced :—

" On the Structure and Growth of the Tissues and ")
on Life " (a course of 10 Lectures) )

" Disease Germs, their supposed Nature"

" Protoplasm, or Life, Matter, and Mind"

" Disease Germs, their Real Nature"

" Illustrations of the Salts of the Urine, Urinary
Deposits and Calculi, including the Structure
of the Kidney in Health and Disease, &c." —
with seventy plates

" Kidney Diseases, Urinary Deposits and Calculus \
Disorders, their Nature and Treatment ' (3rd >

fcH.H I 1<<11/ ••• ••• ••• •«• »!■ •*• ••■ ••« ■ •»

" Archives of Medicine," Vol. 5, No. 17

"On Medical Progress. In Memoriam, R. B. Todd"

Descriptive Catalogue of Microscopic Specimens -\
exhibited at the President's Soiree of the >
British Medical Association. Oxford, 18(58 ...^

" Paper on the Structure and Formation of the so
called Apolar, Unipolar, and Bipolar Nerve
cells of the Frog'' '..

* ' Paper on the Ultimate Arrangement of the Bil
ary Ducts, and on some other points in th
Anatomy of the Liver of the VcrtebrateAnimals

" Science Gossip"

}

3

from
Dr» Lionel S. Beale.

from the PubHsher.

183

" Land and Water" „ the Editor.

" Transactions and Proceedings of the Botanical 7 • exc i, ail « e
Society of Edinburgh." )

" The Monthly Microscopical Journal" from the Publisher.

*' The American Naturalist," for Jan., 1871 in exchange.

20 Slides of Spicules of various Gorgoniadse ... fiom Mr. A. C. Cole.
3 Slides of Ancient iridescent Glass, from the) ■»»- -p m -r, ew ; a

Temple of Venus, Cyprus t i

The thanks of the Club were unanimously voted to the donors.

The following gentlemen were balloted for and duly elected members of the
Club : — Mr. Matthew Hawkins Johnson ; Mr. William Henry Thornthwaite, jun.

Mr. J. R. Leifchild called the attention of the meeting to the subject of fossil
wood, which had greatly interested him for many years, and of which he ex-
hibited a series of 23 specimens, which he considered to be both historically and
intrinsically interesting. They were, he believed, some of the first specimens
ever cut into sections as microscopic objects, having been prepared by Mr.
Saunderson, of Edinburgh, a lapidary not much known to fame, but who was
the inventor of a method of cutting these sections bo thin as to allow of the
passage of light through them. They were cut for the better-known Mr. Nicol
— the inventor of the Nicol prism — and were 23 in number. A fossil tree was
discovered in 1826, at Craig-Leith quarry, near Edinburgh, lying slopingly in such
a manner as to appear to cut through several beds of sandstone of the carboniferous
series; a fact, which, at the time of its discovery, gave rise to several geological
disquisitions. It was further exposed in 1830, and in 1831 a supposed branch being
uncovered Mr. Nicol was then giving his attention to the subject of fossil woods,
and employed Mr. Saunderson to cut the specimens alluded to, and amongst which
were the four sections now exhibited, cut from the Craig-Leith tree. The tree was
now altogether gone, so that no more sections could be had, and the branch was
also gone. A few years afterwards Mr. Henry Witham, of Lartington, near
Durham, published a useful book on fossil woods, which contained some illus-
trations of sections of the Craig-Leith tree, and other trees or portions found
in the North of England, and of which the sections now placed before the
members were specimens. Mr. Witham did not appear to know much about the
species to which the Craig-Leith tree belonged, and it was called Pinites
Withami ; it is now recognised as Hadoxylon. In studying these fossil woods,
the changes made in nomenclature caused some difficulty and required research.
The sections, as microscopic objects, were very fine, and somewhat interesting,
as illustrating the minute structures of the Coniferse. Mr. Nicol was frequently
able to determine the character of the wood by the examination of sections
showing the arrangement of the disc, bearing woody tissue. Since that time the
study of fossil woods had very much advanced, but he thought that Mr. Nicol* s
name ought to be associated with it, because he was the first man who really
gave careful microscopic attention to the subject. One of the specimens upon
the table possessed a particular interest - it was called by Witham Anabathra
pulcherrima, but was, in reality, a stigmaria -the same root-like plant as is found
under clay beds in many coal deposits, with the sigillaria above them. This speci-
men of stigmaria showed very clearly the nature and structure Of this tree.
Eecently the microscope had been applied to the examination of other plants
found in our coal fields. Mr. Carruthers, Professor Williamson, and others, had
given much attention to this subject, and the result would doubtless be, that in
a few years they would possess a far more accurate knowledge of the internal struc-

184

ture of coal plants than was ever expected by such a man as Mr. Nicol. There
was in the British Museum a large and interesting collection of fossil woods, as
well as a considerable number of Mr. Nicol's sections. Mr. Leifchild further
illustrated the subject by reference to some sketches of wood sections, and con-
cluded his remarks by a humourous account of what he termed the Pursuit of
Botanical Knowledge under Difficulties, whilst endeavouring to obtain some
further information upon the subject.

A cordial vote of thanks to Mr. Leifchild, for his interesting communication,
was proposed by the President, and carried unanimously.

The Secretary read a paper by Mr. W. H. Furlonge, " On the Anatomy of the
Flea;" also a note from the author, explaining that in consequence of being
obliged to go to Ireland he was unable to make some alterations and corrections
in the MS., and asking permission to do so before the paper appeared in print.

The President moved a vote of thanks to Mr. Furlonge for his paper, and also
that an opportunity be aiforded him of modifying some of the opinions therein
expressed, as requested in his letter.

Both propositions were at once cordially assented to, and carried unani-
mously.

Mr. B. T. Lowne spoke at some length on the anatomy of the flea, and dif-
fered considerably from Mr. Furlonge's conclusions, although he thought most
of the descriptions were fairly accurate. Mr. Lowne chiefly objected to the
idea that the organ behind the eye is an organ of hearing ; he thought Mr.
Furlonge's evidence on that point was entirely imaginary. He also stated that
Mr. Furlonge was quite wrong about the sacs in the tarsi. Mr. Lowne said if a
flea be killed by chloroform and immediately immersed in glycerine and viewed
by reflected light the whole tracheal system appears as if injected with mercury.
The sacs in the tarsi so viewed are evidently merely ordinary tracheal sacs such
as abound in the stag-beetle and in many other insects. The speaker was of
opinion that Mr. Furlonge had mistaken the tendon of the last tarsal joint for
the main tracheal tube of the limb, and hence his assertion that he could not
trace the communication between it and the sac. Mr. Lowne further stated
that he had isolated the tracheal tube, and found the sac in question to be a
mere tracheal enlargement without any trace of contractile walls, but marked
by the ordinary spiral fibre. With regard to the contractions of the sac, the
speaker stated that they were due to a disturbance of the other respiratory or-
gans. In support of this view he stated that if a flea be examined alive without
subjecting it to pressure the sacs in question do not exhibit any contractions
until chloroform is administered to the insect, but that during recovery the
contractions described by Mr. Furlonge always occur. He examined a living flea
by surrounding it with cotton wool loosely, so that it remained entangled in the
fibres when in the live box. Mr. Lowne ascribed the pulsation in the sacs to the
withdrawal of air from them during the inspiratory dilation of the thorax and
abdomen, the valves of the spiracles remaining closed, instead of opening in the
normal manner. He thought that any injury or pressure would be liable to act
on the nervous system, and produce a similar result. Mr. Lowne horied mem-
bers would try the simple experiment indicated, and they would then be con-
vinced that the contraction of the sacs was an effect and not a cause of the cir-
culation of air, and likewise that it did not occur under normal conditions. Mr.
Lowne then drew attention to the relation of the tendon moving the last tarsal
joint with the sac, and stated that the contraction of the muscle moving the
tarsus by drawing on the tendon caused it to compress the sac slightly, and so

185

force air through the smaller tracheal vessels. Mr. Lowne published his belief
that the muscular movements of insects were a main cause of the respiratory
circulation in his work on the fly, and looked upon these sacs as a strong con-
firmation of his view.

The proceedings terminated with a conversazione, at which the following ob-
jects were exhibited : —

Pulex irritans (alive) by Mr. Furlonge.

Paste Eels (alive) by Mr. J. F. Gibson.

Foot of Water Spider by Mr. H. T. Gray.

Pulex irritans by Mr. des Guimaraens.

Section of Greegree by Mr. Jackson.

Sections of Fossil Wood by Mr. J. E. Leifchild.

Spores of Penicillium by Mr. Martinelli.

Cuticle of Equisetum hyemale

by Mr. J. W. Meacher.

Scale of Eel

Sting of Wasp

Flea (Polar)

Ova of Planorbis corneus by Mr. J. A. Smith.

R. T. Lewis.

THE SOIEEE.

Friday Evening, March 17th, 1871.

By kind permission of the Council of University College, the Annual Soiree of
the Club was again held in their commodious Library, Museum, and con-
tiguous rooms. The company began to arrive shortly before eight, and continued
to swell until nine, when others kept dropping in, till lovers of early hours be-
gan to retire. The Soiree this year was in no respect behind any of its prede-
cessors, except perhaps in one feature, which was universally regarded as an
advantage, that there was less crowding, accounted for by the number of tickets
being limited in issue to members, upon the principle of last year. The in-
terest manifested by the members, and the satisfaction exhibited by visitors of
both sexes, gave no sign of decadence. There was the same sturdy phalanx
of members who had their microscope, and something under it, and the same
smiling and blooming troop of female friends peeping anxiously down the hun-
dreds of brazen tubes erected for their delectation. The prophecy that these
"shows" would soon come to an end, which some crusty antiquarians have
been known to utter, seems as far distant as ever. Here at least was no evidence
that the era of Soirees is coming to a close. The Quekett Club seems resolved
not to be first to discontinue or slacken in their efforts to hold a "gala " once a
year.

The following are some of the objects exhibited by members and friends in the
Library and Museum. Unfortunately this list is very imperfect, and by no means
represents all the objects exhibited. It is hoped that on future occasions exhi-
bitors will assist the Soiree Committee to obtain a more complete list. This
will not only be an advantage to the Club, an acquisition to the Journal, but also
a record for the convenience of members themselves.

186

ACKLAND, W.,

Adkins, W.,

Allbon, W.,
Andrew A. E.,
Andrew, F.,

Bentley, C. S.,
Bevington, W. A.,
Blankney, F.,

Brown, W. J.,
Burgess, M.,
Burr, T. W.,

Cocks, W. G.,
Cottam, A.,
Fitch, F.,

Fricker, C. J.,
Fryer, G. H.,

»

Furlonge, W. H.,

Gardiner, G.,

3?

Gay, F. W.,
Gibson, J. F.,
Golding, W. H.,

3 J

Greenish, T.,
guimaraens, a. de s

Hawksley, —

Hainworth, W. Jun.,
Hind, F. H. P.,

HOPKINSON, J.,
HOVENDEN, G. W.,

Jones, E. F.

Hairs of Buckthorn leaf, polarised by his neutral tint

selenite stage.
Scales of Sole.
Eggs of Water Insect.
Anguinaria spathulata.
Eggs of House Fly (Anthomyia) .
Jaws of Cricket.

Parasite of Ox.
Acari of Sparrow.
Embryo Oysters (opaque).
Hippuric Acid (polarized).

Balloon Newspaper from Paris.

Scales of Ferns shown with new revolving mica selenite
stage.

New live box for spot lens.

New Tank Microscope.

New Portable Microscope.

Polycystina (Barbados).

Hairs on leaf of Onosma Tauricum.

Living Flowers.

Photographs of the Moon.

Minute Writing, " The Lord's Prayer."

Volvox globator.

Transverse section of Porcupiue Quill. (Polarized light.)

Ciliary action in Mussel.

Spider's web and victims.

Crystallized Silver.

Eggs of Bed Spider.

Tank Life.

Dissection of the pygidium of Bed Flea (Pulex irritans),
shewing the trachea and rectal papillae.

Dr. Barker's new Paraboloid, for dark ground illumi-
nation.

Circu'ation in Frog.

Table Kaleidoscope.

Diagrams of Lenses.

A drop of Vinegar with Anguillidse.

Spinnaret of Spider.

Circulation in Frog's Foot.

Elytron and Legs of Brazilian Diamond Beetle.

Section of Tooth showing Enamel and Dentine.
., Section of New Bed Sandstone from Carlisle. (Polari-
scope.)

Eye of a Spanish Dog, showing optic disc, nerves,
arteries, &c, in the retina ; shown by self-illumina-
ting ophthalmoscope.

Entomostraca.

Diatoms .

Daplmia pulex, or Water Flea.

Crystals from the Cork and bottom of a Bottle of Claret.

Marine Alga (Ceramium ciliatum).

187

Jackson, B,D.,
Jaques, E.,
Kilsbt, T. W.,
Lee, Henry, F.L.S.,

Lowne, B. T.,
McLntire, S. J.,

>i

jj
Martinellt, A.,
Matthews, Dr.,

IS

Meacher, J. W.,

»1

ii

»1

OXLEY, F.,

>>

Perry, F. T.,
Quick, G. E.

Eamsbotham, Dr.,

Eeeves, W. W.,

»>

Riddle, E.,

5 J
It

EOGERS, J. E.,
EOGERS, T.,
EUSSELL, JAS.,

)i
n

EUSSELL, JOS.,

jj
»l

EUSSELL, T. D.,

Smith, A.,

11

Smith, Jas., F.L.S.

ii
Smith, W. W.,

Suffolk, W. T.,

Section of Pear, showing gritty tissue.
Wing of Apollo Butterfly.
Section of Horn of Rhinoceros.
First stage of the Prawn.
First stage of Lobster (Homarus vulgaris).
Ocelli on the Wings of Butterflies.
Palate of Sepia officinalis.

Palate of Phasianella australis (polarised lights.
Leg of Hypomeces squamosus (Chinese Diamond Beetle).
Branchial processes from the gill of an Eel.
Carapace of Prawn (polarised light).
Capsules of Mosses.
Flea (Pulex irritans).
Cuticle of Equisetum.
Salicine.

Section of Agate.
Pencil tails (Polyxenus lagurus).
Pollen of Mallow.
Comb from Foot of Spider.
Head of Gnat (Culex pipiens).
Gizzard of Cockroach.
Hairs of Leaf of Alyssum alpestre.
Hairs of Leaf of Onosma Tauricum.
Section of Skin from the Sole of a Baby's Foot, showing
sudoriparous glands.

Section of the Tongue of a Cat (injected).

Section of the Human Finger (injected).

Marble from the Seats of the Judges in the Euins of the

Temple of Claudius Csesar, at Ephesus.
Tongue or Proboscis of Moth.

Granite from Djebel Moussa, or Mountain of Moses,
Sinai ; brought to this country by Capt. Wilson, who
made a survey of the whole mountain.

Hydra vulgaris.

Lophopus crystallinus.

Melicerta ringens.

Water Flea {Baphnia pulex) .

Cyclosisin Anacharis.

Larva of Dytiscus, shewing Trachea.

Foraminifera.

Circulation in Gill of Tadpole.

Tubulipora patina.

A Collection of British Crustacea.

Peristomes of Mosses.

Funaria hygrometrica.
Bryum capillare.
,, Tortula unguiculata.

Echinus with Spines in situ-

Eye of Goliath Beetle.

Echinus Spine (section).

Stellate Hairs of Petal of Correa.

ii

n

188

Tafe, J. F., Scales of Weevil from Philippine Islands (Curculio

pachyrhynclius) .

,, Trichina spiralis in human muscle.

Wright, E., Leg of Beetle, from China.

White, T. 0., Toe of White Mouse (polarised)

,," Tongue of Wasp.

Young, J. T., Eye of Mouse, with Sclerotic removed.

,, Cuticle of Mistletoe Leaf.

In all 91 microscopes were contributed by 71 members.

In addition to the above, eight members of the Croydon Microscopical Club
exhibited as representatives of that Club.

Dr. Marshall Hall exhibited Sponges, &c, obtained in the Noma Expedition.

Fossils were shown by Mr. E. Swain.

Mr. T. D. Russell also exhibited some of his Natural History Collections.

The Chromatic Stereoscope was shown by Mr. W. J. Cocks.

A Graphoscope was exhibited by Mr. T. Crook.

Mr. W. E.Dawes, jun., of High Street, Denmark Hill, exhibited a choice
collection of Stuffed Birds.

Mr.Apps, of West Strand, employed one of the dark rooms for the exhibition
of Electrical Experiments with Induction Coils, Gesler Tubes, Gassiott's
Cascade, &c.

In the Mathematical Theatre Mr. James Martin, of the London Stereoscopic
Company, exhibited on a screen some Photographs of scenes illustrative of the
late war, by the Oxy-hydrogen light

The Flaxman Drawings were exhibited in the Shield Room, by permission of
the Council of University College.

An interesting collection of Photographs of Indian Architecture, kindly lent
for the occasion by Dr. Forbes Watson, F.L.S., of the India Museum, were ex-
hibited in the Museum, together with other Photographs by Mr. J. Van
Voorst, Mr. John Foster, Mr. E. Kiddle, and Mr. A. Shapcott.

The following opticians also exhibited microscopes, objects, and other articles
of interest :— Mr. C. Baker, 244, High Holborn; Messrs. Beck and Beck, 31,
Cornhill ; Mr. C. Collins 157, Great Portland-street ; Mr. H. Crouch, 51,
London Wall ; Mr. T. Curties, 244, High Holborn ; Messrs. Home and Thorn-
thwaite, Newgate-street ; Mr. W. Moginie, 35, Queen-square ; Messrs. Murray
and Heath, 69, Jermyn-street ; Messrs. Powell and Lealand, Euston-road ; Mr.
T. Ross, 53, Wigmore-street ; Mr. J. H. Steward, 406, Strand j Messrs. J.
and E. Swift, 43, University-street.

ERRATA.

The remarks of the President, printed in pp. 149, 153 to 156 of the last
number, were unfortunately sent to press without careful revision, and it may,
therefore, be well to explain that the observations in the last five lines of
p. 149 refer to Mr. Darwin's hypothesis of Pangenesis. In the second line of
p. 156 "pulmonary artery " has been substituted for " aorta.

>>

189

On the Pulex Irritans ; or Bed Flea,

By W. H. Furlonge.

{Read 2±th February, 1871.)

The single family of the Pulicidse, to which the common or bed
flea belongs, is, I believe, generally classed with the Aptera, or
Aphaniptera, though it is, by some naturalists, referred to the order of
the Diptera. It is composed of very numerous species, which are found
upon a vast number of animals, on which they are parasitic. Many
of these species present peculiarities of form and structure of great
interest, and are found to vary in the most remarkable manner with
the species of the animal they infest. The field of observation yet
to be explored, with reference to the Pulicida3,'is a very extensive
one, and although the present paper relates entirely to the one
species, I may just remark, as illustrative of the interest of the
subject, and the varieties of structure found in the different
species, that certain fleas, — notably those of the mole, mouse and
bat, — are either entirely destitute of eyes, or possess them only in
the most rudimentary form, — the antennae, on the other hand, as if
in compensation, — being very largely developed; — that the fleas
found upon many kinds of birds are furnished with plumose an-
tennas of great beauty, which in many cases are carried erect ; —
and that the position, numbers, and form, of the spinous processes
and hairs of the fleas of different animals, present such well-marked
and constant variations, that, in many cases, it is quite possible to
identify, with, absolute certainty, the species of the animals upon
which they have been found. With these general remarks upon
the family of the Pulicidae, I now turn to the special species which
forms the subject of the present paper.

The general form and outline of the bed flea, or Pulex irritans, is
remarkably symmetrical, and even graceful. Although encased in
a suit of mail of the most complete description, such is the won-
derful adaptability of the parts composing it, that the most active

Journ. Q. M. C. No. 15. o

190 W. H. FURLONGE ON THE PULEX IRRITANS.

movements of the animal are in no way impeded, and perfect
flexure of the joints is permitted in every direction. This armour
is composed of exceedingly tough, thin, plates of chitin, of a pale
yellow colour, which assumes a deeper tint with age, and are ex-
quisitely marked with irregular striations. These plates are very
transparent,— in young specimens almost perfectly so, — highly
polished and lustrous. The shape and relative size of the male
and female flea are somewhat different, the former being always
smaller and shorter than the latter.

The external structure of the flea, as of the insecta generally, is
divisible into three parts — the head, the thorax ? and the abdomen,
with their respective appendages. It will be convenient to describe
these parts in their order.

The Head. — The head of the flea is singularly small in proportion
to the size of the animal. It is encased in a helmet of polished
chitin, composed of two pieces — the anterior, or clypeus, and the
posterior, or epicranium, — which are united bj a nearly perpen-
dicular suture, of a light brown colour. The exterior surface of
the head piece is pitted with numerous minute depressions, from
each of which a very small spicule projects backwards. The head
is attached so closely to the thorax, that at first sight it almost
appears to form its anterior segment ; but it is, nevertheless,
capable of considerable movement in every direction. Several
small square flaps, or neck plates, are hinged to the posterior edge
of the head piece, which slide freely over the first segment of the
thorax.

The Eyes. — Undoubtedly, the most striking of the organs per-
taining to the head of the flea are the eyes. When examined under
a \ inch or 4-10ths objective, by reflected light thrown upon it by
the side parabolic illuminator, the eye of the flea presents an object of
singular beauty. It is found to consist of a highly refractive, single,
crystalline, lens, of great brilliancy, the retina pigment of which is
intensely black. Its form is probably spherical, or nearly so, but
it is so set that only a small portion of the lens is visible. It is
situated at the anterior, convex, margin of a deep cavity, having a
nearly semi-circular outline, the curved and diametric edges of
which incline downwards, to form a somewhat pyramidal and rather
deep, excavation, in the side of the head. Nearly one half of this
cavity is covered by a thin, fixed, semi-transparent plate, formed by
the extension of the anterior portion of the headpiece, which,

W. H. FURLONGE ON THE PULEX IRRITANS. 191

starting from the upper anterior portion of the margin of the
cavity, curves, downwards and backwards, to the lower edge of its
base, a little behind the eye, which is entirely surrounded by this
projecting plate.

The Antenna. — Within the chamber thus formed, is situated a
highly curious organ, of complex structure, apparently composed of
a somewhat soft substance of a yellowish-white colour. Its form
resembles that of a curved pear, the smaller extremity being turned
upwards and backwards, and aj^pears to form the orifice of a tube
curving backwards, and expanding into the posterior bulbous extre-
mity of the organ, the upper edge of which is apparently pectinate,
owing to the bulb being transversely cleft, for about half its thick-
ness, into laminas. The entire organ is attached to the anterior
portion of the cavity, by a short muscular foot-stalk or peduncle, by
means of which it can be thrust out, almost at a right angle, hori-
zontally, over the edge of the cavity, at the will of the animal. A
remarkable row of very long, stiff setaa, of a whitish colour, and
about 10 in number, spring from the curved anterior portion of the
organ, projecting backwards and lying in a nearly horizontal posi-
tion above it, for the whole length of the cavity. The fringe, or
brush, thus formed, may, perhaps, simply serve to protect the delicate
structure beneath from particles of extraneous matter, but it is, in
my opinion, more probable that they are sensorial hairs, or seta?,
which convey impressions to the brain, or nervous ganglia, lying
behind the base of the peduncle.

For the more complete protection of this obviously very delicate
organ, a long triangular flap, or valve, of extremely thin mem-
brane, is attached to the edge of the lower portion of the fixed
chitinous plate previously described, and of which it, in fact, forms,
a continuation, when the organ is at rest, so as to cover over about
two-thirds of the opening of the chamber, but when the organ is
protruded the valvular flap is pushed down, returning to its erect
position when the organ is retracted.

The curious pair of organs just described, have generally, and
no doubt properly, been regarded as the antennas of the insect,
but, after much observation, I cannot resist expressing the conjec-
ture that they may probably — specifically, if not solely — serve the
purpose of hearing organs, my reason for this suggestion being as
follows : — From their position, the organs in question are capable
of only very limited movement, and from their peculiar structure,

o 2

192 W. H. FURLONGE ON THE PULEX IRRITANS.

they appear wholly unsuitable to the tentative, olfactory, and pro-
bably other sensorial purposes, served by the antenna? as ordinarily
placed in insects, and when to these considerations is added the
reflection that there is something so very suggestive of acoustical
purpose in the thin membranous plates, extending over deep
chambers in the head, as also in the laminated and apparently
tubular structure of the organ itself, and in the arrangement of the
long stiff seta3 stretching over it, so manifestly adapted to the con-
veyance of the vibratory impressions produced by sound, it is
difficult to resist the inference, that the organ, as a whole, is, at all
events mainly, one of hearing. It is, however, proper to remark,
that in hazarding this opinion, I submit it upon hypothetical grounds
only, as at present I have no proof to offer, of the existence of any
bodies homologous with the otilithes of the higher animals, such,
for example, as those bodies observed by our friend, Mr. Lowne,
in the halteres of the blow fly, which organs he has thereby
been enabled, with great probability of correctness, to identify as
the hearing organs of that insect. Until some such bodies, there-
fore, have been made out to exist in the antenna? of the flea, the
conjecture I have ventured to make as to their being hearing
organs must, despite all my reasons for the opinion, be confessedly
submitted as purely provisional and, indeed, hypothetical.

The Mouth and its Tropin. — We now come to the considera-
tion of the mouth and the complex set of organs composing it.
These, it is by no means an easy matter to make out, in all their
details, in a perfectly satisfactory manner, and though I have devoted
much time to the investigation, I am doubtful whether I have been
able to apprehend, if even to see, all that really exists. The fol-
lowing, however, is the best description I am at present in a position
to offer of this beautiful apparatus.

The mouth of the flea appears to be composed of nine distinct
parts or organs, viz. —

Two maxilla?, two maxillary palpi, two labial palpi, f two man-
dibles, and the Iigula, or suctorial organ.

The Maxilla? are attached to the lower frontal portion of the
head on either side, just within the margin of the headpiece, and
consist of two nearly triangular leaf-like plates of chitin, some-
what thick at their junction with the head, but gradually diminish-
ing in substance until they terminate in very thin, pointed extremities,
which project downwards. The maxilla? are not moveable, and ap-

W. H. FURLONGE ON THE PULEX IRRITANS. 193

pear to serve the purpose, chiefly, of external sheaths or protective
pieces, to the more delicate organs situated between them.

The Maxillary Palpi are a pair of four-jointed, tubular organs,
springing from the anterior portion of the head, and, in their normal
position, project perpendicularly downwards in front of the other
trophi of the mouth. Three of the four joints are cylindrical,
slender tubes, or lobes, having a nearly similar length and diameter,
the terminal lobes being somewhat flattened and spoon-shaped.
The lobes composing the maxillary palpi, are all characteristically
marked by several transverse bands of chitin, which nearly surround,
and doubtless serve to strengthen, the thin, chitinous walls which
envelope them. Their exterior surfaces are thinly studded with
short, fine setas, which probably serve to convey sensorial impres-
sions to the transparent and, I think, fluid contents of the lobes.
In the living animal these organs are in continual, active move-
ment, being pointed upwards or laterally, independently of each
other, and are frequently applied to the surfaces of external objects,
as if for the purpose of ascertaining their nature and properties, in
a manner apparently much more analagous to the action of the
antennae of such insects as the ants and cockroaches (which seem
to be employed as tactile organs) than to the functions of the
maxillary palpi of insects in general. I am inclined from these
observations, to submit the conjecture, in connection with my hypo-
thesis as to the special sense of hearing which I suppose to be served
by the true antennas, whether the maxillary palpi may not, in the
flea, act as supplementary or pseudo antennas, by conveying impres-
sions of surrounding objects, which, from the latent position of the
real antennas, these organs are unfitted to acquire ?

The Labial Palpi are organs of very curious construction. They
are each composed of four tubular joints, (see Fig. 6) united or fused
at their extremities, so as to form one tubular tenon, in which is
inserted a narrow, straight, blade of very transparent chitin. The
top or back of the blade is rather thick, but gradually thins,
like a wedge, to an exceedingly keen cutting edge. . The extremity
of the blade is pointed and projects for some little distance beyond
the tenon in which it is set. The tenon itself, is strengthened by a
layer of thickened brown chitin, and from each of its divisions two
setas project forwards, and four somewhat longer hairs spring from
the extremity.

The Mandibles consist of two very long, thin, narrow and straight

194 W. H. FURLONGE ON THE PULEX IRRITANS.

blades of chitin, the outer surfaces of each being convex, so that,
when closed together, they form a tubular channel or sheath, within
which the suctorial organ, or ligula, is situated. Around both edges
of each curved blade, is set a row of glittering, very transparent,
round and pointed teeth, curving backwards or upwards. These
teeth are not formed by the serration of the edges of the blade,
but appear to be composed of a different and somewhat glassy mate-
rial, and are inserted, separately, in the substance of the mandibles —
after the same manner in which the teeth are set in the rostrum of
the saw fish, to the structure of which, Gosse aptly compares that
of the mandibles of the flea. Immediately behind the marginal
fringe of teeth, and running parallel with it, along the outer or
convex sides of the blades, is placed a second row of glassy teeth,
which seem to me to possess a totally different structure from those
of the margin, being shorter and stouter, somewhat pyramidal in
shape, and standing perpendicularly upon square bases ; and they,
moreover, do not appear to be inserted in sockets as in the case of
the marginal teeth. Each row contains about 75 teeth, so that the
four double rows upon the pair of mandibles are furnished with no
fewer than about 600 separate teeth !

The Ligula or Suctorial Organ, as just stated, lies between the con-
cave surfaces of the mandibles, which, when brought together,
surround and protect it. It consists of an elongated, slender, flexible,
proboscis, having, as I believe, an annular muscular structure, at
least, the tubular channel running through it is certainly striated.
The ligula originates at its junction with the alimentary canal, in
an elongated fusiform cavity, and terminates in a somewhat bulbous
enlargement, the orifice of which is distinctly fimbriated, though
this structure can only be made out by the employment of an objec-
tive of very high power, say a one-sixteenth. Along one side of
the organ is set a series of 11 or 12 rounded, or sub-angular, pro-
jections (see Fig. 5) which are placed at regular and rather wide
intervals, for about one-half of the lower portion of the ligula. It
is extremely difficult to determine, with accuracy, the true nature
of these prominences, but I think I am in a position to state, with
tolerable certainty, that they consist of thin rounded plates or teeth
of chitin, set edgewise in the substance of the organ, and connected
by exquisitely thin cutting edges, curving down between the pro-
minences — the whole arrangement very much resembling the saw
of some species of saw flies. The use of this curious organ is doubt-

TV. H. FURLONGE ON THE PULEX IRRITANS. 195

less to enlarge the orifice, probably first formed by the mandibles and
maxillary palpi, and thus to promote the flow of blood. A high powei
and very careful illumination, is required to resolve the structure ot
this organ, to which I would desire to direct the attention of some of
the accomplished observers numbered amongst the members of this
club, the more especially as the result of my own observations leads
me to differ materially from the conclusions of Mr. Gosse. In a
popular description of the trophi of the flea,* this distinguished
naturalist states that the labrum or upper lip, as he terms the
organ, consists of a narrow chitinous blade, having both its edges
studded with teeth similar to those of the mandibles, but set in a
single row. It seems to me, however, that the organ is not a chiti-
nous blade, but a fleshy, and, I think, muscular, proboscis, perforated
throughout by a canal, and that certainly, it is not surrounded by
a row of teeth.

We now proceed to the description of —

The Thorax, which, as in insecta generally, is formed in three
segments, the pro-thorax, the mezo-thorax, and the meta-thorax,
each division carrying one pair of legs.

The pro-thorax, or anterior segment, consists of three thick plates
of chitin. The superior plate embraces and defends the back, rest-
ing upon it like a saddle, of which the truncated flaps descend on
each side, to the angle of the head piece, at which point they meet ;
and are united to, the two lateral plates, nearly pyramidal in shape
and convex outwardly, which enclose, and in fact constitute, those
parts of the pro-thorax to the anterior angles of which the first
pair of legs is articulated. The three plates composing the pro-
thorax (as is also the case with the plates of the other segments,)
are attached to, and in reality form parts of, a thick membranous
skin, enveloping the whole animal, and which, it may be remarked,
seems to serve a purpose analogous to that of the coat of thick buff
leather worn by the knights and men-at-arms of old beneath their
armour. But only the anterior half of the upper or back plate, is
thus attached to the membranous skin, the unattached posterior
half overlapping the second segment of the thorax, and moving
freely upon it. From the line of junction of the upper plate with
the skin, a series of about a dozen stiff bristles or seta?, emerge at
regular intervals and project backwards. These setas pass through
the chitinous substance of the plate in a horizontal direction, through

* Evenings at the Microscope— p. 178.

196 W. H. FURLONGE ON THE PULEX IRRITANS.

apertures slightly depressed, and furnished with projecting covers ;
but whether the setae are rooted in the epidermis beneath, as I sus-
pect, or spring from the plate itself, I have been unable to deter-
mine.

The mezo-thorax, or second segment, is likewise composed of
three plates, the superior embracing the back, and descending on
either side to about the medial line of the animal, where it terminates
in crescent shaped extremities, into which are fitted the two convex
lateral plates, which envelope and constitute the pyramidal
extremities of the mezo-thorax, to which the second pair of legs is
articulated at the posterior angles of their square terminations. I
am not quite sure that a fourth plate, uniting the lateral plates
beneath, does not exist. I have sometimes thought I could per-
ceive, that the chitinous segment formed a complete ring or collar
round the animal, but of this I am not certain at present. The
anterior half of the upper plate of the mezo-thorax, is attached to
the underlying skin, in a manner precisely similar to that already
described, and from the line of attachment proceeds a like row of
setaa. It may be noticed, that the chitinous plates composing this
segment of the thorax, are considerably stronger than those of the
pro-thorax, the additional strength being given by a marginal band
of brown chitin, of equal width, surrounding each of the three
plates like a frame. I may, in this place, advert to two extremely
curious organs, so far as I am aware, not heretofore described,
which are situated at the posterior portion of the soft part of the
epimeron. These organs are round, dome, or nipple shaped pro-
minences, which are capable of protrusion and retraction, and, in
point of fact, are, in the living animal, continually in movement,
sometimes being projected until the extremities assume an almost
pointed conical form, and at other times retracted until the extremi-
ties of the cone become truncated and nearly flat. In the centre
of each prominence is a cup-like perforation, which, it may be seen,
is connected with a large tracheal tube beneath, of which it appears
to form the external orifice. These curious organs are, without
doubt, spiracles, apparently of a very peculiar type, and regarding
them I shall have more to say in a subsequent part of this paper.

The meta- thorax, or third segment, is much the largest and
strongest of the three, having to carry the third or principal pair
of legs, by means of which, the animal exerts the wonderful mus-
cular power, required for the accomplishment of its extraordinary

W. H. FURLONGE ON THE PULEX IRRITANS. 197

leaps. The strengthening of the plates, by the marginal deposit of
additional material spoken of above, receives, in this segment, a
still further development, and, for the purpose of giving yet greater
solidity to the parts, stout transverse ribs or braces of chitin, at
intervals, unite the anterior and posterior margins of the plates.
In the meta-thorax, indeed, though, in fact, formed of three plates,
like the two anterior segments, these are so firmly united or fused
together, as practically to constitute one very strong plate, embrac-
ing the back and descending on each side, somewhat below the
medial line, terminating in rounded sockets, the margins being
surrounded, or nearly so, by strong rings of dark brown chitin, to
the external edges of which, at the point of junction with the ver-
tical band of chitin, the legs are attached. Afi in the first and
second segments, the superior plate of the meta-thorax is united
to the underlying skin by the anterior half only, and it would
appear, as if the posterior vertical band of chitin is imbedded in the
skin and forms the line of attachment of the plate to it, the posterior
half overlapping and playing freely over the first segment of the
abdomen. Three rows of setee emerge from the meta-thorax, the
anterior set from the middle line of the plate, the posterior row
from its edge, and the third row is placed exactly between them.
Each row contains about twelve hairs.

We now arrive at the description of —

The Legs, six in number, and carried, as before stated, in pairs,
on each segment of the thorax, and attached to them in the manner
already described. The anterior pair of legs is the smallest, the
posterior pair considerably the largest and longest, but they are
all composed of the same number of joints, which are arranged in
a precisely similar manner. They consist of —

1. The Coxa, which in the flea is unusually large, and in fact
constitutes the most important and powerful joint of the leg.

2. The Femur.
2. The Tibia.

4. The Tarsi, consisting of five joints, of which the upper is
much the largest, the terminal joint carrying a pair of Jong, curved
claws, which are capable of contraction, and spring from a soft pad
studded with short hairs. The external surfaces of the legs are
abundantly furnished with stiff setse, of which the thickest and
longest spring from the posterior margin of the tibia?.

The flattened tubular joints composing the legs, are closely

J 98 W. H. FURLONGE ON THE PULEX IRRITANS.

packed, internally, with a dense mass of large, striated, muscular
fibres, constituting the bi-penniform muscles attached to the ten-
dons, which move the successive divisions of the limbs. These
tendons extend to the extremities of each leg, and are attached to
the long curved claws before mentioned, which are powerfully con-
tracted by them. Along the line of the tendon runs a well defined
tracheal tube, from which minute fibres branch in every direction
and permeate the muscular substance.

I have here to describe a most remarkable pair of contractile
sacs, which are to be found in the tibia and upper tarsal joint of
the third pair of legs, and, I believe, also exist in the correspond-
ing joints of the two anterior pairs in a less marked form ; my rea-
son for this opinion being that, in the cat flea, I have distinctly
seen these sacs developed to an almost equal degree in all three
pairs of legs, though they are not to be made out with certainty, in
the two first pairs of legs of the pulex irritans.

The larger and more important of these curious organs is
situated in the upper tarsal joint, through which it extends for the
greater part of its length. It consists of an elongated, ovate,
striated sac, through the axis of, which runs the main tracheal tube
supplying the limb. I have not hitherto been able to make out
that there is any direct connection between the sac and the tracheal
tube. The smaller organ is situated in the tibia, and consists
of a long, flattened, membranous bag or sac, also surrounding
the main tracheal tube, but it is not striated, nor, in my opinion,
contractile.

Having watched the movements of these organs, in the living
animal, by the hour together, I have no hesitation in describing
them, strange as they must appear. The action of the contractile
sac of the upper tarsal joint, is first, by slow distention, to become
filled with air, the membranous sac of the tibia simultaneously col-
lapsing. When fully distended, the tarsal sac suddenly contracts
to about one fourth its previous diameter, when, at the same mo-
ment, the membranous sac of the tibia becomes fully inflated.
This rythmical, alternate, movement sometimes proceeds, regularly,
at the rate of two or three pulsations in the minute, but this is not
always the case, as I have frequently found that it is suspended
for longer or shorter periods, and in many specimens it is altogether
wanting.

Believing that these remarkable organs have not hitherto been

W. H. FURLONGE ON THE PULEX IRRITANS. 199

observed, I have devoted much attention to them, and I think I am
justified in expressing the opinion, that they probably serve a very
important and hitherto unsuspected purpose, in the respiratory
system of the animal, and further, if I am right in my conjecture,
that similar organs will probably be found to exist in many
other insects.

I think it possible, then, that these contractile sacs serve the
purpose of pumps or syringes, by means of which air is drawn
through the external orifices or spiracles, and propelled through
the minute capillary vessels of the tracheal system. I am well
aware that the suggestion sounds somewhat fanciful, but, if this be
not their use, I am unable to conjecture what other purpose they
can serve, and certain considerations, connected with the air circu-
lation of insects in general, and of the flea in particular, to which
I shall advert in another place, seem to point to the necessity for
the existence of some such contrivance. I may add that, hitherto,
I have not been able to discover any external orifice in direct com-
munication with the contractile sac, though I fancy that such an
orifice may exist. I would, however, invite the co-operation of my
fellow members of the Club, in further observations upon these
singular organs.*

We now pass to the consideration of the third division of the
body of the animal, viz. : —

The Abdomen. — The abdomen is divided, vertically, into eight

* In the course of some remarks made by Mr. Lowne, after the reading of this
paper at the Club, a full resume of which will be found in the last number of the
Journal, he referred to certain experiments he had made, with the object of
ascertaining the true nature of these so-called contractile sacs, to which I had
drawn his attention, as really existent, a few days before the reading of my paper.
The result of these experiments and observations, it appears, led him to a some-
what different conclusion as to the structure of these organs, if, according to
his views, they can be so termed. Mr. Lowne regards these sacs as being simply
expansions of the main tracheae supplying the limb, and the apparent muscular
structure to which I attribute the rythmical contraction of the sac, he regards
as a peculiarly marked development of the ordinary spiral fibre; and he looks
upon the dilation and contraction of the sacs as being due to the disturbance of
respiration by the action of chloroform, or even by pressure. Mr. Lowne s
experiments and suggestions are certainly well deserving of attention, but as yet
I have not had an opportunity of testing them. Meanwhile it is worthy of note
that although Mr. Lowne entirely repudiates the idea that the contractions of
the sacs is the cause, but is rather the effect of the respiratory process, he yet
so far adopts my theory as to suppose that the muscular movements of the
limbs compress these tracheal sacs, and that thus air is forced through the
minute capillary trachea. For my own part, though I have directed the atten-
tion of the Club to the existence of these sacs, I do not feel competent to offer
any opinion at present as to their real structure. In fact, I imagine that much
careful work will be required before the true nature and office of these singular
organs can be decidedly affirmed.

W. H. F.

200 W. H. FURLONGE ON THE PULEX IRRITANS.

zones, of which all but the two last are nearly equal in width, each
composed of two, very thin, curved, semi-transparent plates of
chitin, exquisitely striated, polished, and lustrous. The superior
plates embrace the back of the abdomen, and descend, on each
side, considerably below the medial line of the body. The inferior
plates embrace the abdomen proper, and ascend to an equal dis-
tance above the medial line, the rounded extremities of the
plates thus overlapping each other considerably — the superior
plates being the exterior. The seventh pair of plates have a dif-
ferent form from the others, and are somewhat triangular in shape,
the apices projecting backwards, and receiving between them the
terminal segment of the abdomen. This segment is likewise com-
posed of two plates, which differ in structure in the male and
female animals, as will, afterwards, be more particularly described,
when we come to the consideration of the organs of reproduction.
It will be sufficient to say, here, that the upper terminal plate, in
both sexes, is curved and somewhat triangular in shape, the apex,
of course, projecting backwards, and is nearly divided into two
equal parts by a large, rounded or oval opening or excavation,
which bifurcates backwards to the extremities. In this opening is
set the pygidium, as will presently more particularly be described.
The lower terminal plate, which, in this segment of the abdomen, is
the exterior, is also somewhat triangular in general form, the
lateral terminations projecting a little beyond the extremity of the
abdomen.

Owing to the transparency of the structures, it is very difficult to
make out, exactly, how the abdominal plates are attached to the
underlying epidermis, but it would appear as if the anterior portion
only of each plate is thus attached — the posterior portion overlap-
ping and playing freely upon the plate lying immediately behind it.
But, however attached to the skin, each plate of the series is
capable of independent movement in a radial direction, (consider-
ing the medial line as containing the central points of attachment
of the plates), while each pair — superior and inferior together —
frequently move in concert, in a horizontal direction, backwards
or forwards, the segments of the abdomen thus, as it were,
telescoping into each other.

The Spiracles. — Considering them as appurtenances of the ab-
domen, it will be convenient, here, to describe the external respira-
tory organs, or spiracles. Each of the superior abdominal plates

W. H. FURLONGE ON THE PULEX IRRITANS. 201

contains two spiracles, one on each side, — the whole series constitut-
ing two rows of these organs, ranged horizontally, about half way
between the medial line and the top of the abdomen, on either side
of the animal. The first or anterior pair of abdominal spiracles,
however, is situated considerably above the general line, and much
closer to the top of the abdomen. The superior terminal plate
contains two very curious spiracles, presently to be described. In-
clusive of the pair of spiracles, previously mentioned as situated
in the mezo-thorax, therefore, the external respiratory organs of
the flea consist of 18 spiracles, of which those contained in the
seven anterior plates of the abdomen are almost identical in size
and structure. They consist of nearly circular orifices in 'the
chitinous plates, from the inner margins of which about eight or
ten short, stiff hairs radiate, horizontally, towards the centre, thus
forming a protective fringe over the openings. The orifices open
into funnel-shaped cavities beneath, terminating in short tubes,
which are connected to the main trachea in a peculiar manner,
subsequently to be described. A remarkable development of the
external respiratory organs, is found in the two spiracles just men-
tioned, as situated in the eighth or terminal superior plate of the
abdomen. Around the margin of the excavation in this plate,
(within which the pygidium is set,) and curving downwards on each
side, is situated a long narrow groove or channel, (apparently formed
by a duplication of the edge of the plate itself), which is thickly
set with a fringe of short, stiff hairs. Near the superior termina-
tion of the channel, on either side, it is enlarged and deepened, so
as to form a pair of trumpet-shaped funnels, the larger orifices of
which are directed backwards — the smaller orifices being extended
into short tubes, similar to those of the lateral spiracles, which are
united to the main trachea, of which, in fact, they appear to con-
stitute the terminal external orifices.

The Pygidium. — I now come to the description of the pygidium.
(See Fig. 1.) This curious organ consists of a thick, soft, fleshy
mass, of a light-brown colour, in shape something like a saddle, —
the thickened rounded flaps of which descend on either side, the
upper portion forming a sub-angular ridge parallel with the line of
the abdomen. As already stated, it is set within the oval excavation
in the superior terminal plate. The organ rises from, or is attached
to, the surface of the epidermis, or the external fleshy portion of the
animal's body, and is capable of free movement, sometimes being

202 W. H. FURLONGE ON THE PULEX IRRITANS.

protruded considerably, and sometimes being retracted beneath the
margin of the excavation in the terminal plate. The soft spongy
mass, of which the organ appears to be composed, is perforated by
a variable number of circular orifices, from 24 to 28 in number,
between which the surface is thickly studded with very short,
brown, spinous hairs. These orifices open into hemispherical cavi-
ties, around the margin of each being inserted a flat, chitinous ring
(see Fig. 2), from which about ten or twelve flattened bands or
spokes, of the same width, radiate towards the centre for about half
the radius, altogether constituting a flat disc, the inner margin of
which appears dentated, (except under very high powers), from the
projection of the flat bands or spokes ; From the bottom of each
cup-shaped cavity, arises a fleshy cone, the apex of which is in the
centre of the discoid ring, and from it emerges along, fine, straight,
single hair of great flexibility.* These hairs collectively constitute
a tuft or brush of singular beauty, the hairs standing nearly up-
right, or inclining slightly outwards.

When a young and transparent specimen, — of which the large
intestinal sac is well filled with blood, — is gently compressed and
examined by light reflected from a side parabolic illuminator,
numerous thread-like tracheal tubes, (see Fig. 4) may be seen most
distinctly, proceeding from the under surface of the pygidium, (pre-
sumably from the orifices therein), and uniting together into several
larger tubes which join the upper main tracheae of the insect. It
is very interesting to watch the constant movements of the pygi-
dium, upwards, downwards, and laterally, and the consequent waving
motion of the white thread-like vessels proceeding from it, pro-
jected upon the dark back ground of the intestinal sac behind,
which owing to the transparency of the chitinous envelope, can be
seen most clearly.

There has been, and still exists, considerable diversity of opinion
as to the use or purpose of this very curious organ. By some it
has been supposed to be connected with the respiratory system, by
others it is suspected that it fulfils some undiscovered office in the
reproductive functions of the insect, — while the more cautious
observers contend that, as yet, we possess no knowledge whatever on
the subject. T certainly am not in a position to solve the problem,
though I frankly confess that — having reference to the very

* The ideal section of one of the orifices shewn in fig. 3 explains my idea of
the structure I have described.

W. H. FURL0NGE ON THE PULEX IRRITANS. 203

numerous tracheal vessels which, as just described, proceed from
the under surface of the organ and are united to the main trachea
of the animal — I did strongly hold the opinion that the office of
the pygidium was respiratory , — in fact, that it was a collection of
spiracular orifices. Certain facts, however, which have very
recently been brought under my notice by our distinguished member
Mr. Lowne (who, I believe, inclines to the view that the pygidium
is in some way connected with the reproductive organs), seem to
militate greatly against the respiratory theory, which I, therefore,
feel compelled provisionally to abandon. The recent discovery of a
similar organ in the lace fly, however, will probably attract in-
creased attention to the subject, and we may hope that, at no
distant date, the true interpretation of this extraordinary structure
will be discovered.

Having now completed my description of the external structure
of the flea, with the exception perhaps of the male organs of
generation, which will be more conveniently described in another
place, I come to the consideration of the structure of the internal
organs of the animal, which present features of great interest.

I had hoped to have been able to complete my whole subject on
the present occasion, but I think it will be better to reserve the
second division of my paper for another communication, which I
hope at an early opportunity to have the honour of bringing before
the Club the more especially as I desire on that occasion to append
some contributions to the life-history, and development of the
insect, which, I trust, will not be wholly devoid of interest.

Plate XV— Bed Flea (male) X 250.

Plate XVI. — Fig. 1, superior terminal plate, showing pygidium and pair of
spiracles ; 2, side view of pygidium, showing the tracheal tubes ; 3, enlarged
figure of a single orifice in the pygidium ; 4, ideal section of the same j 5, the
labium or ligula ; G, the labial palpi.

204

On a Specimen of Diplograpsus pristis with Reproductive

Capsules.

By John Hopkinson, F.G.S., F.R.M.S.

(Read March 2Uh, 1871.J

In looking over a few Graptolites which had recently been received
by Mr. Etheridge at the Geological Museum, I detected a specimen
which appeared to be a Diplograpsus bearing reproductive capsules.
About half the graptolite as it is now seen was visible ; and this
portion showed the reproductive organs, but no hydrothecaa, the
proximal end being imbedded in the shale. On clearing away the
shale, the specimen, which Mr. Etheridge kindly lent me for
examination, proved to be a tolerably well-preserved impression of
Diplograpsus pristis.

The graptolite appears as a silvery pyritous impression on the
surface of the shale. The proximal termination is indistinct. A
slender radicular process, continuous with the solid axis, can just be
made out. At the distal end the shale is broken right across the
polypary, which here shows no signs of coming to a termination.
One inch only is exposed.

The solid axis is clearly seen throughout. The hydrothecae,
towards the proximal end, are very distinct ; the apertures of those
on the left-hand side are clearly seen, extending partly over the
periderm, while those on the right-hand side are partially hid.
There are twenty- four in the space of an inch. Towards the distal
end the apertures only of a few of the hydrothecee are seen ; they
appear as " scalariform impressions " on the surface of the poly-
pary.

The reproductive organs, which I consider to represent the
gonothecae of the recent Sertularian zoophyte, are developed almost
immediately opposite each other from each side of the periderm and
throughout its whole length. Though at equal intervals from each
other, they are in no even numerical relation to the hydrothecas,

JOHN HOPKINSON ON D1PLOGRAPSUS PRISTIS.

205

Fig. 1.

there being ten to the inch. They appear to have budded from the
periderm at right angles to the hydrothecas, and thus have caused
the polypary to be unevenly compressed. The most perfect are
pear-shaped in form, l-6th of an inch long, and at their narrow
end, by which they are attached, about l-30th of an inch wide.
They have apparently been bounded by a single marginal fibre,
which is slightly thickened at its edges, and, where the pyrites is
removed, has impressed a fine
double groove on the surface of
the shale. If the fibres were
slender tubes this appearance
would naturally be presented ; for
their outer margins would offer
the greatest resistance to com-
pression. The so-called solid axis
of the graptolite frequently pre-
sents a similar appearance. At
the proximal end of the polypary
these fibres only are preserved,
the oldest, or first-formed gono-
thecae having fulfilled their func-
tion and perished. The distal ex-
tremity of even the most perfect
is not clearly defined, the impres-
sion of the capsule in most cases
becoming gradually less percepti-
ble from the proximal to the distal
end. Sometimes the capsules are
irregularly ruptured, their torn
jagged edges being distinctly
seen, while one has split along its marginal limit, along the line of
the marginal fibre, which appears to have parted abruptly near the
distal end of the capsule at one side, and split acutely for some dis-
tance along the other side. This would appear to indicate that the
capsule may be composed of two membranes joined together at their
edges, through which the fibre, if it be not merely a tube formed
by a kind of double marginal seam, has run. In no case can a
distinct unruptured distal orifice be traced.

The gonotheca3 present other peculiar appearances. Towards
their proximal end they are sometimes longitudinally corrugated

Journ. Q M. C. No. 15. p

Diplograpsus pristis
with reproductive capsules.
Magn. 3 diameters.

206 JOHN HOPKINSON ON DIPLOGRAPSUS PRISTIS.

or crumpled, or traversed by fibres which extend for some distance,
into the body of the polypary. Some are much twisted and bent
about, occasionally overlapping each other. Between two which
thus overla]?, or perhaps only come into contact with each other,
just at the point of contact and apparently within one of the cap-
sules, are two minute young graptolites, one lying across the other.
Each consists of a thin membrane, probably
forming the first partially developed pair of s '

hydrotheca?, a minute radicle, and a slender
s olid axis, which is prolonged beyond the
membrane. They are similar in form and

proportions ; but one is a little larger than

., ., ti t ,1 n ,i Young graptolites.

the other. Its length, from the extreme Magu. 6 diams.

point of the radicle to the distal end of the

axis, is l-20th of an inch. The membrane itself is about half this
length, and 1-G0th of an inch wide, tapering towards the proximal
end. The smaller specimen is 1-S0th of an inch in entire length
and l-80th wide. If these young forms had not been in con-
nexion with a mature graptolite they would have been considered
to belong to the genus Diplograpsus, but it would have been impos-
sible to refer them to any species. In their present position I
think we may without hesitation infer that they are the young of
the graptolite with which they are associated. That they have not
yet entered upon independent existence we cannot conclude ; for
they are in different stages of growth, and young graptolites are
frequently met with in a less advanced state than either ; indeed
on the same piece of shale there are several young graptolites
referable to the same species, and no more developed, some even
less so.

This is the only graptolite with undoubted reproductive organs
yet known to have been found in Britain. In America, however,
Professor James Hall has detected 'diprionidian graptolites with
what he describes as " reproductive sacs" or " ovarian vescicles."
These are figured and described in his " Graptolites of the Quebec
Group." In Britain Dr. Nicholson has described and figured, in
the " Geological Magazine," monoprionidian graptolites with what
he has termed " grapto-gonophores." If these should prove to be,
as Dr. Nicholson believes, the reproductive buds of graptolites, the
monoprionidian graptolite is reproduced in a totally different manner
to the diprionidian ; but I think we have as yet had no sufficient

JOHN H0PKINSON ON DIPLOGRAPSUS PRISTIS. 207

evidence brought forward to prove that these problematical bodies
have even any connexion with graptolites. The discovery of this
specimen throws no light upon this mode of reproduction. It
affords, on the other hand, a decided confirmation of Hall's observ-
ations ; and as his views have not been generally accepted, the
specimen is perhaps of more value than if it were unique. The
reproductive sacs figured by Hall are essentially similar to the
gonothecas I have here described ; upon the surface of the shale on
which they occur there are numerous young graptolites in various
stages of growth ; and in one specimen figured, " in connexion
with one of the sacs there are two minute germs, one of them lying
beneath the sac, and the other just beyond its outer margin and
barely separated from its fibres." *

The presence of these reproductive capsules throws some light
upon the affinities of graptolites. It confirms the evidence which
their internal structure has already furnished, of their near alliance
with the Hydroida. The reproductive organs of the Actinozoa and
of the Polyzoa being internal, graptolites cannot, as some think,
belong to either of these classes. In the Hydrozoa they are
external ; and in some of the Hydroida (the only subclass of the
Hydrozoa with which graptolites, having a chitinous polypary, can
be compared) there are reproductive capsules essentially similar to
those of the graptolite, although in no single instance entirely agree-
ing with them. We have no single recent Hydroid with reproduc-
tive organs enclosed in chitinous capsules which are destitute of
any distinct orifice, are bounded by a marginal fibre, or composed
of two membranes united at their edges, and at the same time bud
from the periderm without interfering with the continuity of the
hydrothecas ; but these appearances are all presented by one or
other of the Hydroid zoophytes. In Sertularia, Diphasia, &c, the
gonothecee bud from the periderm in the same manner as in the
graptolite ; in several genera they are ribbed or thickened at their
edges, and in one genus, if not in more, they have no definite
distal orifice. In Aglaophenia, I have been kindly informed by
the Rev. Thomas Hincks, the gonotheca " is oval in form, with-
out orifice, and bounded by a very thin and delicate chitinous
wall."

I need only add that graptolites, having, as is here shown, true
gonothecae as well as. hydrothecse, are most nearly and intimately

* Grapt. Quebec Group, expl. pi. B. fig. 8.

P 2

208 B. DAYDON JACKSON ON AN IMMERSION PARABOLOID.

allied to that order of the Hydroid Ccelenterata known as the
Thecaphora or Sertularina.

The specimen which has formed the subject of these remarks
was collected by the Geological Survey of Scotland, at Leadhills,
Lanarkshire, along with a series of fossils which parallel the rocks
of this locality with those of Moffat, Dumfriesshire, or with the
Llandeilo Flags of Wales.

On an Immersion Paraboloid.

By B. Daydon Jackson.

(Communicated May 26th, 1871.)

I have brought for exhibition an immersion paraboloid, thinking
that a comparison of its powers and mode of working might be in-
teresting to the members of the Club. In using the ordinary
form of the paraboloid with the higher powers, for which it is in-
tended — say, for instance, the four-tenths or quarter inch glasses —
the moveable stop must be brought so near the object that the
extremely oblique rays, coming from the very top of the illuminator,
instead of passing through the slide by refraction, do not enter at
all, but are reflected down on the stop which, in spite of its black-
ened surface, becomes capable of sending up so much light as to
render the field of a neutral tint, or even of a light grey. Some
of these defects are avoided by using the instrument to which I
have called your attention. It is formed of a solid paraboloid of
glass, ground to a different curve than the dry form, and instead of
having its emergent surface hemispherically hollowed out, it is left
nearly flat, a very slight concavity only being given. This con-
cavity is so slight as to be hardly perceptible, but is intended to
permit the slide in contact with it, by means of the water film, to
be moved to and fro without danger of scratching the glass top of
the illuminator — no very difficult thing to do, in spite of the ap-
parent hardness of the substance. The stop to prevent direct rays
passing into the microscope is cemented to the lower surface of the
paraboloid. The object (Eupodiscus argus) is shown by a quarter-
inch binocular with a black field; the angle of the object glass

B. DAYDON JACKSON ON AN IMMERSION PARABOLOID. 209

being about 110°, a result I have not been able to attain so satis-
factorily by any means previously employed. There is no loss of
light by reflection from the lower surface of the glass, since the
rays pass almost in straight lines from the curved sides to the
focus. The ordinary test diatom slide, when mounted dry on the
cover, as usual, present a curious appearance, the field being dark
with a small spot of orange-brown light, occupying about one-fifth
of the diameter, the spherules, however, being shown distinctly. I
have not been able as yet to use this illuminator with higher powers,
the fog surrounding the object unpleasantly.

My acknowledgments for the instrument are due to Mr. Ack-
land, who calculated the curve, and made the paraboloid ; and to
Mr. Suffolk, who obligingly placed all the data in his hands at the
disposal of the first -named gentleman.

NOTICES TO MEMBERS.

The Annual General Meeting of the Club will be held at University College,
on July 28th, at Eight o'clock, for the Election of Officers, Sfc.

Members are requested to deliver to the Secretary the titles of papers and
communications which they intend presenting to the Club at the Ordinary
Meetings during the succeeding six months.

210

PROCEEDINGS .

March 24th, 1871. — Chairman, Dr. Lionel S. Beale,

F.R.S., President.

A list of do