Pibrary of the Museum

Or

‘COMPARATIVE ZOOLOGY,

AT TARVARD COLLEGE, CAMBRIDGE, MASS.

Founded by private subscription, (nr 1861.

Deposited by ALEX. AGASSIZ.
No. [Fe /.

QUARTERLY JOURNAL

MICROSCOPICAL SCIENCE,

EDITED BY

EDWIN LANKESTER, M.D., F.R.S., F.L.S.,
AND

GEORGE BUSK, F.R.C.S.E., F.R.S., F.LS.

VOLUME ILL

With Allustrations on Wood und Stone.

LONDON:

SAMUEL HIGHLEY, 32, FLEET STREET.
om) S55,

LONDON: PRINTED BY W. CLOWES AND SONS, STAMFORD STREET.

INDEX TO JOURNAL.

VOLUME IiIl.

A.

Achromatic condenser, J. D. Sollitt on
a new, 87.

Ayres, Dr. P. B., microchemical re-
searches on the digestion of starch
and amylaceous foods, 247.

Allman, G. J., on Aphanizomenon
Flos-aque and a species of Peri-
dinea, 21.

on the occurrence
among the Infusoria of peculiar
organs resembling thread-cells, 177.
Amphiprora vitrea B? 40,
Amphitetras favosa, 93.
ss Wilkesii, 93.
Amphora angularis, 39.
A Arcus, 39.
ee incurva, 39.

Anacharis Alsinastrum, on the cireu-
lation of the sap, by F. H. Wenham,
Aaale

Angular aperture of object-glasses,
F. d’Alquen on a paper by Dr. Grif-
fiths on the, 43,

Aperture of object-glasses, J. D. Sol-
litt on the, 85. In reply to Mr.
Wenham and Dr. Robinson, 239.

5 F, H.Wen-
ham on, in reply to Mr. Sollitt,
160,

3 os on the, 302.

Aperture of objectives, on the mea-
surement of the, by J. R. Robinson,
D.D., 163.

Aphanizomenon Flos-aque, G. J. All-
man on, 21.

Arcyria, threads of, 20.

Artificial light, prevention of the
glare from, Ferguson Branson,
M.D., on the, 173.

Arts, Society of, Prizes offered by
the, for cheap microscopes, 234, 306.

VOL, Il.

Atlantic, microscopic examination of
deep soundings from the, by J. W.
Bailey, 89.

Aulacodiscus Oreganus, 93.

B.

Bacterium termo, Cohn on, 206.

Bailey, J. W., and Prof. W. Harvey,
description of new species of Dia-
‘tomacee, 93.

microscopic examina-
tion of deep soundings from the
Atlantic, 89.

on some new localities
for fossil Diatomacee, 91.

Bennett, J. H., on the structure of
the Torbane Hill mineral and of
various kinds of coal, 185.

Bleakley, E., M.D., on Powell and
Lealand’s new condenser, 92.

Blood-cells, action of urea on, 289.

Branson, F., M.D., on the prevention
of glare from artificial light, 173.

3 on the circulation
of sap, 274.

Bridgman, W. K., on another ‘finder’
for the microscope, 237.

Busch, Dr. W., on Noctiluca miliaris,
199%

C.

Calex Mosquito, C. Johnston, M.D.,
on the auditory apparatus of, 97.
Campanularia geniculata, on the male

reproductive organs of, by Dr. Max.
S. Schultze, 59.
Campylodiscus clypeus, R. Wigham
on, 243.
Kiitzingii, 93.
Car penter, W.B., review of principles
of comparative ’ physiology, 2b:
4

A

326

Cellulose in animals, by R. Virchow,
284,

Chytridium, Cohn on, 207.

Cilia in the Diatomacee, J. Hogg on,
235,

5, on the surface of Conferve, Dr.
G. H. Kingsley on, 243.

Circulation of the sap in the leaf-cells
of the Anacharis Alsinastrum, by
F. H. Wenham, 277.

Closterium Lunula, 8. G. Osborne on
the economy of, 54.

“, structure of, F.G. Wright,
M.D., on the, 171.
Cocconeis costata, 39.
» parmula, 93.
Eas rhombifera, 94.
» suleata, 94.
a speciosa, 59.
3 transversalis, 39.

Cohn, Dr. F., researches on the de-
velopment of microscopic Algz and
Fungi, 202.

Colouration of the China Sea, Camille
Dareste on the, 66.

Condenser, new. Powell and Lea-
land’s, Dr, Bleakley on, 92.

Confervee, cilia on the surface of, 243.

Conversaziones, Microscopical, 303.

Cornea, compound of insects, 9. *

Currey, Frederick, on the reproduc-
tive organs of Fungi, 2638.

A on the spiral threads
of the genus Trichea, 15.

Cutaneous follicles of the toad, on the
structure of, by George Rainey,
257.

Cymbella truncata, 38.

D.

Dareste, Camille, on the colouration
of the China Sea, 66.

Deep soundings from the Atlantic,
microscopic examination of, by J.
W. Bailey, 89.

Delicate test-objects, definition of,
E. L. on the, 233.

Diascope, a new optical instrument,
description of, 1.

Diatomacew, cilia in the, J. Hogg on,
235.

Diatomaceous deposits in the mud of
Milford Haven, description of, and
mode of procuring, by Fitzmaurice
Okeden, 26.

if, earths and elays, mode
of washing, F, Okeden on a, 158.

“5 exuvie contained in a |

post tertiary lacustrine sand from
Glenshira, 30.

INDEX TO JOURNAL.

Diatomacee fossil, new localities for,
J. W. Bailey on some, 91.

3 on washing and concen-
trating of, Dr. H. Munro on the, 241.

x8 new species of, descrip-
tion of, by Prof. W. Harvey and J.
W. Bailey, 93.

Diatomacez, on the determination of
species in, the Rev. W. Smith on
the, 130.

55 on species of, 307.

Discopora ciliata, 256.

D’Alquen, F., on Griffiths’ paper on
the angular aperture of object-
glasses, 43.

E.

Enamel and dentine of the teeth,
T. H. Huxley on, in reply to E.
Lent, 127.

Enlargement and multiplication of
the images of objects when viewed
through small apertures, J. Gorham
on the, 1.

Ereolani and Vella.on the develop-
ment and life of the Nematoidea,
73.

Eunotia falx, 38.

Eupodiscus? Ralfsii, B, 39.

F.

‘Finder’ for the microscope, on an
improved, by F. Okeden, €.E.,
166.

5 for the microscope, W. K.
Bridgman on another, 237.

Finders, 314.

Flies’ feet, on, 312.

Freshwater marls and_ limestones,
microscopical structure of, H. C.
Sorbey on the, 95.

Fungi, the reproductive organs of, by
F. Currey, 263.

G.

Geological Society, proceedings of, 95.

Glaisher, J., on snow-crystals, 179.

Glare from artificial hght, ou the
prevention of, 173.

Glenshira deposit, Diatomaceous exu-
vie in, 30.

Gonium pectorale, Cohn on, 212.

Gorham, J.. on the magnifying power
of short spaces, 1.

Gregory, W., on diatomaceous exuviz
contained in a post tertiary lacus-
trine sand, from Gleushira, 30.

Griffith, Dr. J. W., on the angular
aperture of object-glasses, 43.

INDEX TO JOURNAL.

H.

Hepworth, John, memoranda by, 312.

Histology, Quekett’s lectures on, re-
view of, 75.

Hodgson, W., on an easy method of
wiping thin glass covers, 243.

Hogg, Jabez, on cilia in the Diato-
macee, 235.

Hunt, G., description of a curious
effect of moisture on the markings
of Pleurosigma, 174.

5 on the markings of the
Pleurosigma, 232.
Huxley, T. H., on Noctiluca miliaris,

i on the enamel and
dentine of the teeth, 127.
Hyalosira punctata, 94.

Is

Illumination, new mode of, by Dr. T.

G. Wright, 236.

= of microscopic objects,
F. H. Wenham on the, in reply to
Mr. Rainey, 87.

Impressions, metallic, of microscopic
objects, mode of obtaining, F. H.
Wenham on a, 244,

Infusory animalcules, physiological
studies respecting the, by Paul
Laurent, 156.

Infusoria, on the occurrence among
the, of peculiar organs resembling
thread-cells, by G. J. Allman, 177.

Insects, feet and wings of, J. Tyrrell
on the, 230.

a $5 by J. Hep-
worth, 312.

Isthmia minima, 94.

J.
Johnston, C., M.D., on the auditory
apparatus of calex mosquito, 97.

Jungermannia, elaters of, action of
sulphuric acid upon, 19.

K,

Keber, F., on the porosity of bodies, |

152.
Kingsley, Dr. G. H., on cilia on the
surface of Conferva, 243,
Kolliker, on the motions of spermatic
filaments, 293, 296.
» on the action
blood-eells, 289.
», On lymph corpuscles, 291.

of urea on |

|
|
|

L.

Lagena Williamsoni, 94.

Laurent, Paul, physiological studies
respecting the infusory animalcules,
156.

Lent, Ed., on the enamel and dentine
of the teeth, 127.

Lepralia scutulata, 255,

Leydig, Dr. F., on the structure and
systematic position of the Rotifera,
136.

Lloyd, W. A., on artificial sea-water
in marine aquaria, 315,

Lymph corpuscles, Kolliker on, 291.

M.

Magnetic stage, description of a, by
J.B. Spencer, 174.

Magnifying power of short spaces, J.
Gorham on the, 1.

Marine aquaria, on the employment
of artificial sea-water, 315.

Membranipora Sophie, 255.

Memoranda, by John Hepworth, 312.

Menipea arctica, 254.

Microchemical researches on the di-
gestion of starch aud amylaceous
foods, by Dr. P. B. Ayres, 247.

Microscope, Dr. H. Schacht on, trans-
jated by F. Currey, review of, 219.

Microscopes, cheap, proceedings of
the Society of Arts with respect to,
234, 306,

Microscopic Alge and Fungi, re-
searches on the development of, by
Dr. F. Cohn, 202.

Microscopical Society, proceedings of,
176, 247, 317.

Moleschott, on the motions of Sperma-
tozoids, 294.

Monas prodigiosa, 206.

Moreland, Mr., on starch, 319.

Munro, Dr. H., on the washing and
concentrating of Diatomacee, 241.

Muscular fibre, on, 318,

N.

Navicula crassa, 41.
a gastroides, 40,

5 maxima, 41,
es rhombica, 40.
6 birostrata, 40.

Nematoidea, on the development and
life of the, 73.
Noctiluca miliaris, Dr. W. Busch on,
199,
a 3 T. H. Huxley on,
49.
oF x Dr. Woodham
Webb, on, 102.

328

O.

Okeden, F., on an improved ‘ finder’
for the microscope, 166.
,», on diatomaceous deposits
in "the mud of Milford Haven, 26.
55 », on a mode of washing
diatomaceous earths and clays, 158.
Osborne, S. G., on the economy of
Closterium Lunula, 54.

1 Ph

Pathological Anatomy, Manual of, by
C. H. Jones, M.D., and E. H.
Sieveking, M.D., review of, 155.

Pedicellaria of Echinus miliar is, figure
of, 83.

of Sputangus purpureous,
figure of, 84.

Peridinea, new species of, G. J. All-
man on a, 21.

Physiology, comparative, principles
of, W. B. Carpenter, 215.

Pinnularia apiculata, 41,

“5 Gastrum, 41.

Pleurosigma, curious effect of moisture
on the markings of, 174.

5 markings of the, G. Hunt
on the, 232.

Polythalamia (Foraminifera), M. 8.
Schultze on the organization and
classification of the, 143.

Porosity of bodies, microscopic re-
searches on the, by F. Keber, 152.
Post-tertiary lacustrine sand con-
taining diatomaceous exuvie, W.

Gregory on, 30.

Powell and Lealand’s new condenser,
R. Bleakley, M.D., on, 92.

Pulmonary Consumption, Dr. Theo-
philus Thompson’s Lettsomian lec-
tures on, review of, 227.

Q.

Quekett’s, J., Lectures of Histology,
review of, 75.

R.

Rainey, George, on the cutaneous
follicles of the toad, 257.

Redfern, P., M.D., on the Torbane
Hill mineral and on other varieties
of coal, 106.

Reproductive organs, on the, of cer-
tain Fungi, by Frederick Currey,
263.

INDEX TO JOURNAL.

Robinson, J. R., D.D., on the mea-
surement of the aperture of objec-
tives, 163.

Rotifera, on the structure and sys-
tematic position of the, Leydig on,
136.

Royal Society, proceedings of, 247.

Ss

Salicornaria borealis, 254.

Savory, Mr., on muscular fibre, 318.

Sea-water artificial, on the employ-
ment of, in marine aquaria, 315.

Sertularia imbricata, 256.

Schacht, Dr. H., on the microscope,
219;

Schultze, Dr. Max. S., on the male
reproductive organs of Campanu-
laria geniculata, 59.

on the or-
ganization and classification of the
Polythalamia (Foraminifera), 143.

Smith, the Rev. W., on the determi-
nation of species in the Diatomacez,
130.

Snow-crystals, J. Glaisher on, 179.

Sollitt, J. D., on a new achromatic
condenser, 87.

ss on the aperture of
object-glasses, 85.

Sorbey, H. C., on the microscopical
structure of freshwater marls and
limestones, 95.

Species of Diatomacez, on, 307.

Spencer, J. B., description of a mag-
netic stage, 173.

Spermatic filaments, action of alkalies
on, 293, 296,

Spermatozoids, motion of, 294.

Spiral threads of the genus Trichia,
Fred. Currey on the, 15.

Starch, Dr. P. B. Ayres, on the diges-
tion of, 247.

,, the presence of in the blood,
Se dh aueeon on, 168.
5 r, Moreland on, 319.
sete s. J., on the presence of
starch in the blood, 168.
Surirella fastuosa, B, 40.
Synedra undulans, 41.
5 vertebra, 41.

fb

Thin glass covers, on an easy method
of wiping, by W. Hodgson, 243.
Thread-cells, on the occurrence of
peculiar organs resembling _ the,

among the Infusoria, 177.

INDEX TO JOURNAL.

Toad, cutaneous follicles of, by
George Rainey, 257.
Torbane-Hili mineral, and on other
varieties of coal, P. Redfern, M.D.
on the, 106.
structure of,
&e., J. H. Bennett on the, 188.
Triceratium coneavum, 94.
35 gibbosum, 94.
A orientale, 94.
a Wilkesii, 94.
Trichia, British species of, 21.
» on the spiral threads Oe Tby.

Trichia-threads, corrections of mis- |

prints in Mr. Currey’s paper on,
176.
on mode of preparing,

21.

Tryblionella constricta, 40.

Tyrrell, J., on the feet and wings of
insects, 230.

Tubulipora ventricosa, 256.

Ue
Urea, action of, on blood-cells, 289.

Vi.

Vibrionia, Cohn on the nature of, 206.
Virchow, R., on cellulose in animals,
284,

|
|

329

W.

Ward’s, Mr., conversaziones, 303.

Webb, Woodham, M.D., on Noctiluca
meliaris, 102.

Wenham, F. H., on a method of ob-
taining metallic impressions of mi-
i objects, 244.

on the illumination
of microscopic objects, in reply to
Mr, Rainey, 87.

+ on the circulation of
the sap in Anacharis Alsinastrum,
Die

reply to Mr. Sollitt
on the aperture of object-glasses,
160.

1: on tests mounted in
balsam, 302.

Wigham, R., on Campylodiscus cly-
peus, 243.

| Wright, Dr. T. G., on a new mode of

illumination, 236.
» F.G.,M.D., on the structure
of Closterium, 171.

Z.
Zoophytology, 253, 321.

LONDON :

Printed by W. Crowes and Sons,
Stamford Street.

QUARTERLY JOURNAL

OF

MICROSCOPICAL SCIENCE.

ORIGINAL COMMUNICATIONS.

On the ENLARGEMENT and Muttipiication of the Imaces of
Oxssects, when viewed by the Light admitted through small
Apertures ; and on the Diascorr, a new Optical Instrument.
By Joun Gornam, M.R.C.S.L., &c.

(Continued from Vol. II., page 234.)

It has been before noticed that less attention has been
bestowed upon the investigation of objects that lie near at
hand, within an inch or two, we will suppose, of the eye, than
upon objects which are placed at a considerable distance from
it, that, for example, of as many furlongs. I have also endea-
voured to show that small circular perforations made in a
card, and rendered semi-transparent, constituted in themselves
objects well adapted to illustrate the magnifying power of short
spaces, by presenting a rapid and palpable enlargement of
the visual angle to the eye ; and, lastly, a series of phenomena
has been described, which resulted from viewing small figures
held close to the eye in front of such apertures, and rendered
visible by the light admitted through them.

The whole subject arranges itself therefore under two dis-
tinct divisions, which comprise :—1. An examination of the
images formed by viewing objects held zn front of small aper-
tures ; and 2. An examination of those images which result
from placing the objects behind the apertures.

1. Of images formed when the eye and the object are both
on the same side, that is, in front of the apertures.

We have already seen that when bodies not exceeding the
diameter of the pupillary opening of the eye are held in close
proximity to the visual organ, and are then examined by the
light admitted through small inlets about the fortieth of an
inch in diameter, their images become maynified, multiplied,
and inverted ; and further, that they are illuminated with light

VOL. ITI. B

2 GORHAM, ON THE

of an intensity varying with the number of apertures employed
to render them visible.

This light, be it observed, is always simply transmitted ;
never being "reflected nor refracted by the intervention of
glass, or ts: any other substance having catoptric or dioptric
effects. The apparatus required in these experiments there-
fore is éssentially very simple and uncomplicated, consisting
indeed of a mere short tube open at one end, and haying a
plane, perforated with small holes to admit ihe light, at the
other; while the object to be examined is applied at the open
end, and held as close to the eye as possible. Hence a pill-
box and a narrow slip of glass constitute all that is really
necessary to explain the laws which are in operation, and to
give an idea of the phenomena which are involved in their
successful application.

From the remarks made in a previous section, it is obvious
that these phenomena are owing to the size, and to the
intervals of the apertures themselves, and to their distance with
respect to the eye. Thus their size should be the one-fortieth
of an inch,—their intervals the one-tenth of an inch,—and their
distance from the eye from one to two inches. If these con-
ditions are not fulfilled, the images become either undefined
or dimly illuminated ; but when they are strictly observed, the
combinations, which an instrument constructed upon such prin-
ciples is capable of presenting to the eye, are very beautiful.

But a mere tube of pasteboard, however well it might
answer for a first experiment, is inefficient, for it is difficult
to retain the slip of glass in its proper position between the
tube and the eye. It was essential therefore to construct a
small instrument of some more solid
and durable material, such as wood
or ivory, with which experiments
might be conveniently performed.

This instrument consists of a tube,
T, one or two inches long, and about
one inch thick, expanding at the end
to which the eye is applied into a
circular lip, L, which is about one’
inch and a half in diameter, while
that of the round opening in its centre »
is about half an inch. This end is
provided with a slit sufficiently large
to permit a thin narrow slip of glass,
about an inch broad, to slide easily
through it, as Steen in the figure.
The other end:has/a\ circular rim, R,

MAGNIFYING POWER OF SHORT SPACES. 3

which revolves in the groove, G, and to this rim is attached
a second rim, 7, which is provided with a female screw, and
this secures any circular plane of apertures, p, we may choose
to insert, at the same time that it admits of its revolution.

A series of objects, either painted or mounted on glass slides,
can thus be examined at one end by the light admitted through
perforated planes at the other. As such an optical contrivance
is a mere conductor of the light directly from the apertures to
the eye, while at the same time it excludes all the extraneous
rays, it may not inaptly and for convenience’ sake be denomi-
nated a diascope: a term derived from the two Greek words,
dia, through, and cxomew, I view. And when it is used for
the purpose of multiplying images, it may be called the mui-
tiplying diascope.

The circular planes containing the apertures are made of
thick pasteboard, perforated with a needle at intervals of the
one-tenth ef an inch as before stated; and the openings may
be arranged in a variety of combinations, as shown in the
patterns from one to six, page 225, of the last paper.

Here let us notice that the round form of the images, de-
picted on the retina when examining small apertures in this
way, is determined by the shape of the pupillary opening of
the eye rather than by that of the apertures themselves.
Hence it is always circular whether these be round, triangular,
square, or altogether irregular in outline. ‘This can easily be
proved by perforating cards with triangular or square needles,
The openings thus made when brought very near to the eye
always appear circular. A little reflection will show that this
is a necessary result, inasmuch as the outermost rays of the
rapidly-diverging cones are intercepted by the zrzs, while the
more internal rays pass on through the pupil, thus receiving
their circular form.

Hence if the pupil be widely expanded the discs will be
large, and vice versd, but nevertheless always perfectly round.

Let us now take a circular plane, presenting a combination
of perforations arranged as to colour and relative position as
in the outline, No. 4, page 225, of the last paper; and let
us notice what kinds of images are presented to the eye when
small bodies are examined by the light transmitted through
them.

Holding the instrument to the eye with a view to examine
the apertures, we observe that the smallest particle of dust, or
film of mucus, happening to exist on the surface of the
transparent cornea, is immediately detected; and although
such bodies have no definite shape, they are to be recognised
interfering with the transparency of the discs, and forming an

BZ

4 GORHAM, ON THE

opaque spot or streak which occupies exactly the same posi-
tion in each. Similar results are obtained if a small dot, no
bigger than a pin’s head, be made on a slip of glass with
Indian ink, and introduced into the eye-piece of the diascope.
The dot now appears multiplied, and as many images of it are
seen as there are apertures by which it is made visible.

In like manner if a small semicircle be painted on glass, its
images will be multiplied, but each image will be seen in-
verted, and will appear as a black body on an illuminated and
coloured ground.

And if a small triangle, or any other figure of definite
shape, be cut from a piece of black paper, and if the opening
thus made be examined in the same way, a number of illumi-
nated and coloured triangles will be seen on a black ground.

It is when transparent figures are made according to this last
method that really beautiful combinations may be produced.
But here, in order to insure success, it is necessary that the
transparent openings should never exceed in size the pupillary
aperture of the eye, fig. 16. Hence they should always be
made within the limits of a circle, the 0°18 of an inch in
diameter, fig. 15; this being the mean of the greatest and least

Fig. 15. Fig. 16.

o &

expansion of the pupil. If such transparent figures are made
greater than this, the margin of the pupil will obstruct some
of the external rays, and the outline of the image will thus be
lost or badly defined. If, on the other hand, they are less, the
quantity of light admitted into the eye will be too small, and
the images but feebly illuminated.

Such openings used as objects are to be considered as little
else than artificial pupils, modifying the shape and contracting
the size of every cone of light which is admitted into the eye
from small apertures,

When one of these transparent openings is held close to the
eye, and examined with common diffused light, it becomes
altogether invisible ; but, when it is viewed by the aid of a
pencil of light from a small inlet, its outline is well defined
and much magnified ; and the disc of the inlet, which would
otherwise be circular, is replaced by the pattern we may
choose to give to the transparency.

And if the pupil of the eye itself, obliterated, as it often
is, from disease, have a small portion excised from it, as in

MAGNIFYING POWER OF SHORT SPACES. +)

the operation for artificial pupil, the newly-formed opening
will appear inverted and multiplied in the same way; and
each image, instead of being circular as it is in the healthy
eye, will be seen to resemble the figure of the new and dis-
torted pupil.

But in order to demonstrate the images which this instru-
ment is capable of presenting to the eye in the most satisfac-
tory manner ; instead of cutting holes in pieces of black paper,
a series of figures having a transparent body and a black out-
line may be painted on glass with Indian mk. For this
purpose round patches of Pale about the size of a fourpenny
piece, should be laid on the centre of each glass slip with a
camel’s-hair pencil ; and, when dry, transparent figures of the
required shape and cintewsrons can easily be Higdes by erasing
a portion of the ink with a finely-pointed and slightly-moist-
ened wooden style.

The forms of such transparencies will suggest themselves
to the ingenuity of the reader, but a few are subjoined by way

of example (figs. 18 to 33).

Fig.18. 19 2 25.

Fig. 18. Regular hexagon. | Fig. 28. Two semicircles.
4, JIS Hexagonal star. | ,, 29. Triangle and semicircle.
», 20. Rhomb of 60°. | ,, 380. Curved and straight lines
», 21. Curved triangle. | intersecting at 60°.
», 22. Ditto. | ,, 31. Three lines intersecting at
», 23. Trefoil. | 60°.
» 24. Circle. » o2. Two curved lines inter-
», 25. Concentric circles. | secting at 60°.
», 26. Triradiate star of 120°. ,, oo. Two angles of 60° inter-
», 27. Straight lines intersecting secting.

at 60°,

Such forms arrange themselves into two groups; those, for
instance, which are entire in themselves, and which constitute
elegant ‘designs by their multiplication. and the shifting of
their Pere position (figs. 18 to 25), and those again which
are imperfect figures, but which produce entire compositions
of great beauty by their combination (figs. 26 to 33).

6 GORHAM, ON THE

As the apertures are arranged in lines which cross each
other at angles of 60° and 120°, the outlines of the transparent
figures should bear the same angular relation. Thus the
modifications of the equilateral triangle, the rhomb of 60° and
120’, and the regular hexagon, a few of which are given in the
above examples, are well suited for the purpose.

When a transparent hexagonal star (fig. 19), slid into the
eye-piece of the instrument and brought close to the eye, is
examined by the light admitted faces a combination of
apertures, that, for instance, marked No. 4, at the 225th
page, placed at the other end, the images of a number
of stars are apparent. ‘These stars are seen to change their
relative position with every movement, however slight, of the
revolving plane. Sometimes they are observed to touch each
other by one ray, at others by two, while in intermediate
positions the rays alternate. The patterns which are thus
formed are as variable as the parts into which a circle can be
divided. ‘They are shown in two of their phases of revolu-
tion in the 4th and 5th figures of Plate VIII., Vol. IL.

The concentric circles, fig. 25, thus multiplied display
themselves with good effect. Their appearance is represented
in the 6th figure of Plate VIII., which is produced by using
the arrangement of apertures marked No. 5, page 225.

But the combinations effected by the mutual coalescence of
the images of the imperfect figures into one entire composite
form are the most curious. Thus if the three-rayed star,
fig. 26, be examined, its images will be seen either to alter-
nate (fig. 9, Plate I., Vol. IIL.), or to resolve into one hexa-
gonal reticulation with a dot in the centre of each mesh, as
shown in fig. 10, Plate I., Vol. III. And the images of the
figure, composed of the straight and curved lines, fig. 30, unite
into many fresh devices; two of which are copied in the
figures 7 and 8, Plate I.

But it is needless to multiply examples, as those which have
been already given will doubtless have sufficed to explain the
construction of the instrument, and one of the purposes at
least to which it may be legitimately applied.

Hitherto we have confined our attention chiefly to the mu/-
tiplication of the images of artificial objects prepared expressly
for the purpose, and viewed by the aid of the light admitted
through small apertures.

We are now to consider how the images of natural objects
are magnified by the same means.

Here let us notice, in limine, that we are not about to insti-
tute a comparison between two optical instruments, the eye
and the achromatic microscope, which although they are con-

lod

MAGNIFYING POWER OF SHORT SPACES. (

structed on the same principles are yet totally different as to
their uses. The healthy visual organ, itself a perfect instru-
ment, ‘ converses with its objects” at almost all distances,
and assists the other senses in becoming acquainted with the
form, position, and magnitude of material substances. The
microscope, on the other hand, all but a perfect instrument,
enables us to see clearly and to examine certain objects,
which from their small size and without its aid would be
indistinct, if not altogether invisible, It is restricted to the
small size and the short distance of its objects, and from its
very construction it has magnifymg powers which the eye
neither possesses nor requires. If the eye were endowed
with these, therefore, to the exclusion of its self-adjusting
properties, whereby it discerns common objects in the ordinary
way at great and small distances, it would be rendered com-
paratively useless as a visual organ.

Hence it were folly to attempt to invest this organ with
functions, the possession of which would subject its owner to
the greatest inconvenience. An exemplification of this position
occurs to me in the case of short-sighted persons,

When therefore we find ourselves enabled by a carefully-
devised experiment to detect, with the naked eye, certain
configurations upon or within an object which, we may sup-
pose, has never before yielded an image at all excepting
through the medium of a lens, we are not to imagine that we
are thereby infringing on the domains of the microscope,
which being constructed for this very purpose would present
us, perhaps, with an image ten thousand times as large and
distinct. But putting this instrument altogether out of con-
sideration, and throwing aside all extraneous assistance, we
are the rather to consider how the eye, which has certain
limits to distinct vision for short distances, can yet adjust
itself for spaces still smaller, and in so doing become con-
verted into a kind of natural magnifying glass.

We have now therefore to turn our attention to certain
microscopic objects, which are to be examined and resolved
without a lens of any description; and we are stimulated to
an investigation of this kind by recollecting what has been
already attained with respect to the magnitude of the images
of small apertures themselves, when placed under circum-
stances the most favourable for their inspection. Amongst
these we cannot fail to have noticed at least two conditions
necessary to be fulfilled in such investigations, viz.—First,
that the object be held very near to the eye; and secondly,
that every ray of light, excepting what is required to illumi-
nate the object, be carefully excluded. The first insures an

8 GORHAM, ON THE

enlarged image, whilst the second prevents a too great con-
traction of the pupillary opening. Hence the necessity for
examining objects through small darkened tubes, and hence,
too, the necessity for closing the eye which is not engaged in
exploring.

Again, we must not overlook the fact, that in using a small
aperture for the purpose of examining any transparent sub-
stance there are two methods which may be employed. By.
the one, the object is viewed through the aperture; by the other,
the aperture is viewed through the object. The former has been
almost always adopted by the curious, the latter scarcely ever.
It is capable, however, as these papers show, of eliciting so
many phenomena peculiar to itself, that I am surprised it has
not been frequently used, and the results carefully investigated.
Each of these plans throws a different picture on the retina
of the eye, and of this the transparent animal membrane chosen
for the following experiments will afford, when examined in
both ways, abundant exemplification.

For the purpose of presenting very small objects, mounted
on microscopic slides in the usual way, before the eye at
small distances behind a minute aperture, and to exclude the
surrounding rays of light, I took an upright box of pasteboard
about one inch and a half deep, and one inch and a quarter in
diameter, and having cut a couple of slits through one of its
sides sufficiently large to admit of a slip of glass an inch
broad sliding to and fro, I made two small apertures opposite
to each other, the first the one-thirtieth of an inch, and the
second the one-fourth of an inch in diameter ; and these were
so disposed, that when the glass slip with a small object

mounted on its centre was introduced through the slits, the
two apertures and the object were all in one straight line ;
while the slide was about a quarter of an inch behind the
smaller opening, see fig. 34.

MAGNIFYING POWER OF SHORT SPACES. 9

With this simple apparatus I could examine very small
transparent objects at pleasure, either by the light of the sun
or of a taper. Whilst, however, it has been thought better to
notice the dimensions of the apertures, &c., for the conveni-
ence of others who might wish to repeat the experiments, it
must not, by any means, be supposed that they are the best
adapted to insure success, or that better could not be devised.

Having been engaged in the preparation of 1 series of dis-
sections of the compound cornea of the eye in insects, I naturally
subjected one of these beautiful objects to the first experiment
in my lens-less microscope. Here, however, for the informa-
tion of those who may not be conversant with these objects, or
the peculiarities of their structure, it may be remarked that
the roundish, prominent, transparent elevations observed,
generally one on each side of an insect’s head, constitute the
membrane in question. This membrane forms at once the
defence and the covering to the delicate parts in the interior
of the eye, as well as ihe transparent medium by which the
light is admitted into this tiny organ. It is analogous, more-
over, to the transparent cornea of the eye in the higher iclacces
of animals in being transparent, composed of several firmly-
adhering layers, and forming the outermost of all the coverings
of the eye. But it is altogether dissimilar in this respect,
that it is found to consist of an immense number of facets or
little pieces lying, side by side, like fine mosaic; and which
from being of a regular hexagonal shape, and arranged in
perfect order, present when examined under the microscope
an appearance like a honeycomb. Hence it has received the
name of compound cornea.

The eye of the large insect, called the dragon-fly, is recom-
mended for a first trial in dissection, because it is not only
very large but exceedingly beautiful. The compound cornea
is at once separated from the rest of the eye with a pair of
finely-pointed scissors, and the dark thick pigment which fills
the inside is then washed away by soaking in a tumbler of
cold water for an hour or two, and then using a camel’s-hair
pencil. ‘To procure it in a perfectly clean and transparent
state, however, it is better to wash and rewash it after macera-
tion for two days in frequently-changed cold water. Then,
while still moist, let small circular pieces be excised with a
small punch, and pressed immediately between two slips of
glass. In a few days they will have become dry and flat, and
may then be mounted in what is called the dry way, as if for
the microscope.

I wish it was in my power to convey to my readers an idea
of the great beauty of one of these specimens ; to say nothing

10 GORHAM, ON THE

of the wonderful arrangement whereby upwards of twelve
thousand planes, each a perfect hexagon, are packed in a bit
of membrane scarcely so large as half the little finger nail,
‘“‘] have often,” says the celebrated Leeuwenhoek, “ made re-
peated dissections of the eyes of various kinds of insects,
merely on account of the pleasure the contemplating them
afforded me.”* But few, however, seem inclined to investi-
gate these subjects for ‘themselves, trusting rather to that
second-hand kind of knowledge derivable from books. This
distaste for exploring the works of nature may possibly, in
some instances, commence with the limited resources of the
pocket ; the very preparation of a microscopic object in-
volving the necessity for a costly instrument wherewith to
investigate it. If, however, I shall succeed in pointing out
certain beauties peculiar to the compound cornea in the eye
of the insect, which may be discovered with the naked eye,
and without a microscope, this membrane will have become
invested with a new interest, and thus others may be stimu-
lated to a like inquiry. But to return. Having inserted a
slide containing a circular section of the eye of the dragon-fly
in the box prepared for the purpose, I proceeded to examine
it. Recalling to mind, however, that each of the hexagonal
facets is barely the six-hundredth of an inch across, and that
many hundreds of such facets are contained in the smallest
section, it was much to anticipate that such a structure should
be 7esolved by a process so simple ; and when on viewing the
membrane, by looking at it through the small aperture, while
a lighted amie was held nearly close to the larger one, it
presented a semi-opaque and altogether homogeneous appear-
ance, I had almost concluded that my efforts were frustrated.
To overcome the difficulty was reserved, however, for a future
trial. Now if, instead of a candle, a small wax taper be used,
and if this be held at the distance of from five-to nine feen
rather than close to the large aperture, a beautiful sight pre-
sents itself. Instead of the flame of one taper, there: are
exhibited the miniature images of the flames of many tapers;
and these are not only very definite in their outline so as to
be immediately identified, but they are arranged at regular
intervals, But, what is still more curious, each image, except
the central one, is seen to be composed of the colours of the
prismatic spectrum,—violet, indigo, blue, green, yellow,
orange, and red; of which the extreme tints are so disposed
that the blue portion in each image is always nearest to the
central or colourless flame, and the red the most remote from
it. Hence the blue and the red tints alternate in concentric

* Leeuwenhoek, vol. ii. p. 341.

MAGNIFYING POWER OF SHORT SPACES. 11

circles. When the images which are most distinct, for those
near the margin look fainter, assume in the aggregate the form
of the hexagonal star, which they not unfrequently do, the
appearance is striking and uncommon, see fig. 11, Plate I.

The simplicity of the process by which such a spectacle is
produced, together with the novelty of the sight itself, did
not tend, of course, to diminish the sense of its gorgeousness ;
and I was delighted to find a natural multiplying glass in
a tissue, which had already contributed so much to my ad-
miration and wonder when examined under a compound
microscope.

On viewing the sun in the same way, each small and per-
fectly circular image presented the rainbow tints in the same
order, as in fig. 12, Plate I., and the multiplied images of the
pale moon were scarcely less beautiful.

I may remark, in passing, that the taper flame and the
image of the moon were seen through a specimen mounted in
Canada balsam ; but the rays of the sun were less distressing
to the eye when examined through a specimen mounted in
the dry way.

Thus, although I had not, in this experiment at least, suc-
ceeded in rendering visible a magnified image of each hexagon
in outline, which indeed was the object of my research, I had,
in effect, resolved the reticulated structure of the membrane;
for in this way only could the peculiarities of a multiplying
medium have presented themselves. The interval between
each image served, moreover, to indicate the apparent enlarge-
ment of each facet, and thus to give a notion of the magnify-
ing power of short spaces.

Still bearing in mind the comparatively enormous magni-
tude imparted to images on bringing the objects which pro-
duce them very near to the eye, and recollecting that the image
of a mere needle-puncture seen at half an inch is magnified
no less than a million times, it was difficult to renounce the
idea of the practicability of defining the hexagonal lattice-
work of an insect’s eye with the naked eye, and without the
assistance of a material lens.

In the former attempt the membrane seemed too opaque to
disclose its minute internal configuration, a specimen was
therefore now mounted in balsam to increase its transparency.
This, however, did not succeed; on the contrary, it had
become so indistinct that its structure could now be scarcely
made out even with a microscope. In order to define the
hexagons it was evidently necessary to colour the membrane.
A few specimens were macerated, therefore, for four days in a
decoction of logwood, and then carefully dried and mounted

12 GORHAM, ON THE

in balsam. In this way they were rendered sufficiently
diaphanous to transmit a strong light from the sun without
injuring the eye, and their reticulations were not obscured

Having prepared the object, it was necessary to decide upon
the distance from the eye best suited for examining it; and
as the nearest position would insure the largest image, this
was accordingly adopted. The mode of illumination also
required consideration, in order that the light should be of
such intensity as to make the object visible without dazzling
or injuring the eye. The quantity of light received by any
object is often measured with an instrument invented for the
purpose, called a photometer ; but a box with small apertures
pierced through the bottom might be shown to constitute a
good and efficient substitute for such an instrument. For it
is to be inferred from the remarks contained in the sixth para-
graph, that when a small object is examined by the aid of the
pencils of light admitted through such apertures, it is illumi-
nated by the sum of their intensities. Hence the quantity of
light thrown upon the object will be regulated by the number
of the apertures, being very nearly proportional to them: that
is to say, the intensity from two apertures will be nearly twice
as great as that from one.

By varying the number of apertures, therefore, we can regu-
late the illumination of the object with the greatest nicety.
It follows that there is no better way, perhaps, of exploring
minute objects with the naked eye, than by holding them,
mounted on a slide of glass, as near to the eye as possible, and
examining them by looking at them from the inside of a small
box through apertures made in the bottom, and which are
covered with tracing-paper, by the aid of a strong light.

And this is effected by using the little instrument, to which
I have ventured to give the name of diascope.

Thus all the conditions were fulfilled; for, 1, the object
was rendered sufficiently transparent to transmit the rays of
light freely, and sufficiently opaque to prevent the solar rays
dazzling the eye ; 2, it was coloured to make all its parts visible ;
3, it was brought sufficiently near to the eye to be enormously
magnified ; and 4, all extraneous rays of light, those which
were not immediately concerned in the illumination of the
object, were shut out. It remains to be noticed that the ex-
periment was crowned with success; for, on examining the
membrane by the direct rays of the noonday sun, the whole
of its area appeared reticulated, and several well-defined
hexagons were seen in its centre. While, as a red tint had been
communicated to the specimen, its reticulations were most
easily discerned in the red discs, inasmuch as the tints of all

MAGNIFYING POWER OF SHORT SPACES. 13

substances are most brilliant when viewed in light of their
own colour.

By way of recapitulation, I shall beg to sum up with the
following remarks :— .

1, When small bodies are brought very near to the eye,
their images are magnified, just as images of larger objects
when seen at a distance are diminished, and by the same law.

2. The apparent magnitude of objects depends on their
visual angle.

3. The visual angle, for short distances, may be well illus-
trated by employing a small circular disc of light.

4, A minute circular disc of light is procured by perforating
a card with a needle, through which the light is then permitted
to pass.

5. A sewing-needle, of the size marked No. 6, produces an
aperture about the one-fortieth of an inch in diameter.

6. In order to examine the light which is transmitted
through such an aperture, all extraneous rays should be ex-
cluded ; hence the plane in which the opening is made should
be placed at the end of a tube.

7. The pencil of light admitted through an opening of this
kind, held within an inch or so of the eye, consists of rapidly-
diverging rays falling upon the cornea. Some of these are
entirely lost, others are intercepted by the iris, while the re-
mainder pass on through the pupil, which communicates to
the image formed on the retina its circular form.

8. Whether the small aperture itself be round or triangular,
square or irregular, in form, provided its area do not much
exceed that of a circle the one-fortieth of an inch in diameter,
its image is always circular.

9. When more than one aperture is used, and these of
different tints, secondary colours result from the overlapping
and blending of the images of the primary.

10. If the three primary colours, yellow, red, and blue are
used, their images, which overlap in pairs, produce orange,
violet, and green light; and when the images of all three
blend white light is the result.

11. When a small transparent object is held close to the
eye it is altogether invisible.

12. But its outline is immediately determined by the light
transmitted through one of the small inlets above described,
and it is then seen to be not only magnified but inverted.

13. The image becomes much more distinct when more
than one aperture is used, for the intensity of light by which
it is illuminated is thereby increased, being almost in a direct
ratio with the number of the openings which are employed.

14 GORHAM, ON THE

14. The pencils of light which are used for this purpose
not only illuminate the object, but intersect in their passage
through it, producing as many images as there are apertures.

15. Hence, when a small object is examined by the light
admitted through small apertures, it will appear magnified,
inverted, multiplied, and illuminated with variable degrees of
intensity.

16. The apparent magnitude of an object varies with the
distance of the source of light by which it is rendered visible ;
when this recedes, the pencil of light has less divergence, and
the object appears smaller; when, on the other hand, it ap-
proaches the eye, the visual cone has a rapid expansion, and
the object still held in the same position appears magnified.

17. All these effects are demonstrable by using artificially-
prepared transparent figures, the dimensions of each of which
do not exceed the diameter of the pupillary opening of the
eye.

"18. It is probable that the minute structure of many natural
transparent objects may be recognised in the same way. The
hexagonal facets in the eye of the dragon-fly certainly can.

19. These phenomena are, for obvious reasons, but imper-
fectly discriminated by short-sighted persons.

20. And, finally, it should be noticed that the investigations
resulting in the phenomena described in these papers were
commenced, and have been conducted throughout, for the
specific purpose of testing the power of the naked eye in con-
centrating the rapidly-diverging rays of light, proceeding from
bodies when held at very short distances from it unaided by a
lens ; and from these inquiries it would appear, amongst other
results, that the magnifying power of the eye is limited by the
magnitude of the visual angle on the one hand, and by the
intensity of light on the other. Ifthe visual angle be too large,
the rays are not sufficiently refracted by the humours of the
eye to converge to a focus, and form an image on the retina ;
and if too small, the image is reduced to a mere point. The
exact amount of divergence of the rays, therefore, for any
individual eye lies somewhere between these two extremes.
Again, however nicely adjusted the visual angle may be to
the refractive powers of the eye, if the light be too strong the
pupil becomes so contracted that only the innermost rays are
admitted ; while, if it be of small intensity, the object is so
dimly illuminated as to be scarcely visible. If, then, whilst
a small object is held very near to the eye, so as to insure
a rapid divergence of the rays proceeding from it, the pupil
can be dilated by the small quantity of light which is used,
and to which like a photometer it immediately responds, so as

MAGNIFYING POWER OF SHORT SPACES. 15

to admit as large an angle as the lenses of the eye are capable
of refracting, at the same time that the object is rendered
distinctly visible, then, under such circumstances, we have
arrived at the utmost limit to the available magnifying power
of the eye. These conditions are fulfilled in the diascope ;
which may be defined to be an instrument which enables us to
develop the microscopic power of the eye by retaining an object
close in front of it at one end, while it is examined by the light
admitted through small apertures at the other.*

With such a simple optical instrument, altogether destitute
of glass, a series of images may be presented wineh have never
before been seen with the naked eye; and by its use we are
led to a legitimate conclusion, capable of direct proof, that
when a transparent figure is held very near to the eye for the
purpose of magnifying it, if an image is seen at all, its size
will bear an inverse ratio to the intensity of light by which it
is made visible.

In my next communication, which will embody the second
part of the subject, I shall beg permission to describe and de-
lineate another set of forms distinct from those which have
been noticed in this, and which are produced by substituting
straight or circular very narrow apertures of light for the per-
forations. With such apertures, figures are seen as in perspec-
tive, lines appear expanded into planes, and these are multi-
plied into solids, which, from being of an ethereal brightness,
bear a resemblance to models of regular geometric solids of
pure glass.

On the Sprrat Tureans of the Genus Tricu1a. By Freprrick
Currey, Esq., M.A.

Ir anything were wanting to show the extent of the field of
research, which is open not only to the student but even to the
more advanced inquirer in botanical microscopy, it would be
sufficient to direct attention to some of the many points in
vegetable anatomy upon which the opinions of observers not
only differ from one another, but are so utterly and diameiri-
cally at variance, that if the one side be right the other must
be altogether wrong. Commencing upon the threshold of
vegetable life, opinions are still divided as to the structure of
the primary membrane of the walls of young cells, Mulder
and Hasting contending that the young cell-membrane is
pierced like a sieve, whilst Von Mohl asserts that it is com-

* This instrument may be procured at Mr. Highley’s Scientific Library,
32, Fleet-street, London.

16 CURREY, ON THE SPIRAL THREADS

pletely imperforate. Again, the question of the mode of
growth of the thickening layers (that is, whether they are de-
posited upon the outer or inner side of the primary membrane),
although considered by some botanists to be quite decided,
has lately been discussed at some length in a new work by
Dr. Schacht,* which shows that the subject is not yet ex-
hausted. The apparently fibrous structure of many liber-cells,
the nature of the milk-vessels, the connexion between spiral
and reticulated vessels, the structure of the chlorophyll gra-
nules and starch, are all matters upon which our present
knowledge must be considered imperfect. A long list might
be placed before the reader of questions respecting vegetable
structure, upon which the opinions advanced upon the one
side are flatly contradicted on the other. Without multiplying
instances, | may mention the question of the origin of the
embryo in phenogamous plants as one peculiarly illustrative
of the point to which I have alluded upon this question.
This question, which although physiological in its import, can
only be decided by anatomical investigation, embraces two
parties whose views are hopelessly irreconcileable ; yet each
side is equally positive. Each party asserts that they have
actually seen that which they describe, which it is hardly
necessary to remark is just as impossible as that a thing
should be both black and white. Schleiden alleges that he
has set the matter at rest by his investigations, and established
an incontrovertible theory ; Von Mobl states that Amici has
destroyed Schleiden’s theory at one blow, and that the matter
is quite settled in its principal features the other way.

The spiral threads, which it is the object of this paper to
discuss, hold a conspicuous place amongst disputed vegetable
structures, so far at least as relates to the variety of the
opinions entertained respecting them. The genus Trichia
constitutes a tribe of minute fungi, growing principally, in fact
almost exclusively, upon rotten wood, and generally of a
yellowish or tawny colour. They belong to the order of the
Gasteromycetes, in which the spores, which are often inter-
mixed with hairs or threads, are developed in the interior of
a case, termed a peridium or sporangium. ‘They form part of
the sub-tribe Myxogasteres, in which the plants first appear in
the form of a slimy mucilaginous stratum, out of which at a
later period the spore-cases are developed. The different
species of Trichia grow in various ways; in 7. pyriformis
the peridia are joined together in a fasciculate manner, in 7.
clavata they are scattered at small distances from one another,

* Beitréige zur Anatomie und Physiologie der Gewachse, by Dr. H.
Schacht. Berlin, 1854.

OF THE GENUS TRICHIA. 1 Li

in T. chrysosperma the pertdia, although quite distinct, are
so densely aggregated as to cover completely the spot upon
which they are spread, in T. serpula the peridia are flexuous,
creeping, and irregular in shape. When the fungus is mature
the peridium bursts, and the spores in its interior are dis-
charged, It is generally supposed that one purpose for which
the threads are designed i is to assist in scattering the spores,
for their elasticity is very great. Ifa specimen of Trichia be
examined immediately after the bursting of the peridium, the
threads are seen protruding through the fissure and apparently
struggling for egress; when viewed through the microscope
at this period with a low power, they have a slow waving
sort of motion, not unlike that of the threads of the Ones
torie ; if the whole of the mass of threads be extracted with
a needle it appears like a small fragment of yellow wool.
When a minute portion of this yellow flocculent mass is ex-
amined moist, under the microscope, with a power of about
200 Giemerers, it is seen to consist of narrow delicate fibres
_having fine spiral markings covering the whole of the walls.
A reference to fig. 1, Plate im hich shows a fibre of Trichia
chrysosperma, will give a general idea of this spiral appear-
ance; and it is with repard’ to the nature of these threads, and
the cause of their spiral appearance, that so much difference of
opinion exists. Corda claims to have discovered these threads,
~ which he calls spiral-fibrous-cells (spiral-fiber-zellen) ; but they
were observed about the same time by Mr. Berkeley, and in
fact could not fail to have been noticed by any person hap-
pening to examine a fragment of the woolly mass with a
moderately good microscope.*

Corda, in a letter addressed to Baron Humboldt, and which
was published at Prague in 1837, enters at some length into the
nature of these spinal-fibrous cells, and considers them to be
analogous to the elaters of the Jungermannie. After ad-
mitting that weighty objections might be raised against the
comparing of them with the spir al cells found in the walls of
the capsules of the Jungermannia, and in the sporangia of
the Equisetacez, or with those in the leaves of Sphagnum, he
comes to the conclusion that no unprejudiced person can deny
the following facts with regard to their structure :—

1. That they consist of a simple or stratified cellular mem-
brane.

2. That this membrane encloses one or more spiral fibres.

3. That the spiral fibre is of a rigid fibrous structure.

He then traces the spiral form through the cells of

* The structure seems to have been jirst noticed by Hedwig, Obs. Bot.
Fasc., i. p. 14; and next by Kunze, Myc. Heft II., p. 94.

VOL, III. C

18 CURREY, ON THE SPIRAL THREADS

Nepenthes and the vessels of the Conifere up to the perfect
spiral vessel, and afterwards the degeneration of the perfect
spiral vessel into the ‘“‘worm-shaped bodies” (wurmf6ninge
kérpen) in the tubers of the Orchidew and in other plants,
concluding with an expression of opinion that these spiral
fibrous-cells must be considered as imperfectly developed
forms of the spiral vessel.*

Soon after the publication of Corda’s observations, Mr.
Berkeley noticed the threads in question in the Annals of
Natural History, and stated that so far as he had investigated
them they differed in no respect from the spiral vessels of the
higher plants.

The next observer was Schleiden, whose opinion was en-
tirely opposed to the fibrous theory of Corda and Berkeley.
He (Schleiden) says that he has reason to believe that no
spiral fibre exists, but that the threads are flat band-like cells
spirally twisted, thus attributing the spiral appearance to the
existence of a twist in the cell-wall. Dr. Schacht in his ad-
mirable work, *“* Die Pflanzenzelle,” subscribes to Schleiden’s
opinion, and states that he was long ago convinced that no
spiral band exists, but that the appearance by which Corda
was deceived arises from the torsion of flat thread-like cells.
According to Schacht, Dr. Klotzsch found that in an early
stage of the threads no spiral appearance was visible.

Mr. Henfrey in a late communication to the Linnzan Society
has given the result of his own observations, and expresses a
very confident opinion as to the existence of a spiral fibre; so
much so that, having the greatest faith in the observing powers
of Schleiden and Schacht, he is driven to doubt the goodness
of their instruments.

A careful examination of the threads of several species of
Trichia has led me to a conclusion different from those of the
observers above referred to; and I will proceed to state the
objections which appear to me to exist against the theories of
Corda, Berkeley, and Henfrey on the one side, and of Schacht
and Schleiden on the other. There is no substantial difference
between the views of Corda and Berkeley, who agree in the
main point of the existence of a spiral fibre. In the first
place the non-existence of spiral vessels in other genera of
fungi | (Batarrea perhaps excepted) affords some prima fucie
ground for supposing that the organisms in question do not

* Corda’s expression is, “* Hrstarrte Trawmbild,” meaning literally, ‘ a
vision become rigid.”

t+ Bonorden, in his ‘ Handbuch der Allgemeinen Mycologie,’ states,
that a spiral fibre exists in Arcyria punicea ; but this, I apprehend, is a
mistake.

OF THE GENUS TRICHIA. 19

contain fibres. It does not seem probable that spiral vessels,
which have always been considered a type of advanced organi-
zation, should be altogether wanting in the vast tribe of the
Hymenomycetes, that they should disappear at the close of the
series of the higher Cryptogamia to come to light again in the
lower scale of the Gasteromycetes: this argument of course is
by no means conclusive, but in a question where so much
difference of opinion exists it is deserving of consideration,
and cannot safely be altogether rejected. Again the shape of
the Trichia-threads exhibits a great departure from the ordi-
nary form of spiral vessels; Schacht, in the work to which I
have alluded, asserts that spiral vessels are seldom branched,
and mentions two instances as cases of unusual occurrence, in
which branched spiral vessels have been observed : the accu-
racy of this statement has been questioned, and it has been
alleged that spiral vessels are frequently branched, especially
in endogenous plants ; but whichever view be correct, [ appre-
hend that a branched spiral vessel must be considered abnormal
in form, and consequently when we find, as was long since
noticed by Corda, that the Trichia-threads are very frequently
branched, and sometimes to an extent almost amounting to
reticulation, this fact must be admitted to weigh something in
the scale against the probability of the existence of fibres.

Another objection arises from the rapidity with which the
Trichia are matured. It is well known that the Myzogasteres,
as well as some other of the Gasteromycetes, grow with
astonishing rapidity. Batarrea gaudichaudi, a South Ame-
rican species, attains its full size in a few hours ; the develope-
ment of Phallus impudicus is familiar to every person who
has directed any attention to the subject of fungoid growth,
and the genus Trichia forms no exception to this rule. Now
if spiral fibres exist, they must be admitted to be formed in
the same manner as all other spiral fibres are supposed to be
produced, viz., by gradual and successive deposits of thick-
ening matter upon the internal wall of the cells; and if this be
so, it is difficult to see how, in the short period allotted for the
completion of the growth of the fungus, the fibres can find
time to perfect themselves.

A further objection arises from the impossibility of de-
taching the apparent spiral from the wall of the cell; I assume
that this has never been effected, because if it had been the
question would be concluded. I have tried the action of
many reagents upon these threads, but have never succeeded
in obtaining a free fibre. Now if the elaters of a Junger-
mannia, with which more than with anything else the Zrichia-
threads have been compared, be treated with sulphuric acid,

Gz

20 CURREY, ON THE SPIRAL THREADS

the cell-membrane is dissolved and the spiral fibre left free ;
I have tried the effect with the TZrichia-threads, and have
found them either to resist the action of the acid altogether, or,
if the acid operated, that the threads became uniformly
charred, but presenting nothing to lead to the conclusion of
the existence of a spiral fibre. Moreover, if iodine and sul-
phuric acid be employed, the effect produced upon the cell-
wall and upon the supposed spiral fibre is the same.

Another objection to the fibre theory appears to me to arise
from the unevenness or rather waviness of outline which exists
in almost all the threads which I have examined, and which is
not usual in spiral vessels in general ; and also from the fact
that the end of the supposed fibre is never to be seen pro-
truding from the cell, which might be expected when the
threads are ruptured as they frequently are.

The theory of Schleiden and Schacht that the spiral ap-
pearance is caused by the twisting of flat band-like cells is
very difficult to be maintained, and I cannot help thinking
that they have formed their opinions from an examination
only of such simple threads as are represented in figs. 1 and 4,
It might be possible for the spiral appearance in such cells to
be produced by a twist, but I cannot conceive how the “ Dre-
hung um sich selbst,” as Schacht expresses it, of the cells can
be calied in aid to explain the spiral appearance in such a
thread as that of 7’. serpula, shown in fig. 8; the thing seems
to be mechanically impossible.

If the above theories be incorrect, it may be asked, in what
other manner is it possible to account for the spiral appear-
ance? Now it seems to me that 1t may be accounted for by
supposing the existence of an accurate elevation in the wall of
the cell, following a spiral direction from one end of the
threads to the other.) /(Dhis supposition would, I think, accord
well with the optical appearances, and it Soul account ‘exactly
for the undulations of outline to which I have before referred.
I have in my possession a thread of Trichia chrysosperma, in
which the spiral appearance is so manifestly caused by an
elevation of this nature —in which it is so clear that no internal
spiral fibre exists—that I do not think there could be a doubt
in the mind of any person carefully examining it with a power
of 500 diameters, that the cause of the spiral appearance is
not a spiral fibre. I have also a species of Arcyria, in which
the threads are (as in the other Arcyria) echinilate or denti-
culate, and the teeth appear to take a spiral direction round
the threads; these teeth are mostly at a short distance apart ;
but at a spot where the teeth are so close as to have become
confluent, the appearance produced is almost precisely the

OF THE GENUS TRICHIA. 21

same as the appearance in the Trichia-threads. I have seen
on one occasion the membrane of a thread of J. pyriformis
unrolled spirally in the manner represented in fig. 10, Plate
II. ; this circumstance is somewhat curious, as membrane does
not ordinarily unrol in that manner, although it has been
observed by Professor Quekett to take place in the hairs of
the fruit of Cycas reroluta.* 1 do not know that this fact has
any very strong bearing upon the question of structures; but
if, as would seem to be the case from its greater transparency,
the elevated position of the cell-wall is thinner than the rest,
it is easy to imagine that a rupture of the wall would be likely
to take a spiral direction.

The following is a list of the Triehia hitherto recorded as
British, viz., Trichia pyriformis, serotina, fallax, clavata, tur-
binata, chrysosperma, varia, Serpula, Neesiana,+ and Ayresit ;
and to these must be added Trichia nigripes, which I met with
last autumn in the neighbourhood of Eltham in Kent.

With regard to the preparation of the Trichia-threads for
the microscope, there are many methods which may be used.
Owing perhaps to the dense crowding of the hairs, the getting
rid of air-bubbles is the principal difficulty. Alcohol is the
easiest medium to employ, and I have reason to think that the
colour of the threads is not affected by it, which is the only
thing which might be feared. Deane’s gelatine is a very good
preservative, and may be used without difficulty if the threads
are previously left to soak for some hours in chloride of cal-
cium ; and castor oil answers admirably well, although when
this is used there is sometimes a little difficulty in fixing the
thin glass cover. In conclusion, I would venture to express a
hope that some of the readers of the Microscopical Journal
may be induced to direct their attention to the investigation of
these disputed threads ; irrespective of the interesting question
of structure, the beauty of the objects will fully compensate
them for the trouble of examination.

Observations on APHANIZOMENON F'Los-aquH, and a species of
Peripinga. By G. J. Atiman, M.D., Professor of Botany
in the University of Dublin.

Tue substance of the following communication has already
appeared in the Proceedings of the Roval Irish Academy ;

* See Lectures on Histology, p. 100.

} Fries has expressed an opinion that Zrichia Neesiana is identical with
T. rubiformis ; Bonorden, however, asserts, that in 7. rubiformis there
is no spiral appearance. If this be so, they cannot be identical; for 7.
Neesiana shows the spiral marking more beautifully than any which |
have examined,

22 DR. ALLMAN, ON

but having made some additional observations, I have thought
them of sufficient interest for publication in the Microscopical
Journal. The first part of the paper consists of the results
of some observations made on Aphanizomenon Flos-aque.
This minute alga has appeared in great abundance in the
large pond of the Zoological Gardens, Dublin. The best
account we possess of the plant is in an excellent paper on
the Nostochinee, by Mr. Ralfs;* but as the specimens from
which Mr. Ralfs’s description was drawn up were not in a
recent state, some important points of structure have neces-
sarily escaped him.

A. Flos-aque shows itself in the form of little fusiform
fasciculi, of a pea-green colour (Plate III., fig. 1), which are
most frequently seen united to one another in larger bundles,
fig. 2. This union of the primary fasciculi into secondary
ones is not permanent, and under certain circumstances very
imperfectly understood ; but, in some cases, depending perhaps
on meteorological conditions, the secondary fasciculi become
broken up into primary ones, or, at least, into less compli-
cated bundles, and the plant, which had previously lain upon
the surface of the pond in an extensive stratum, becomes nearly
uniformly diffused through the water. <A return of the former
conditions will again cause the union of the simpler fasciculi
into more complex ones, and the reaccumulation of the plant
in masses on the surface.

The primary fasciculi are composed of straight filaments,
which are about 1-3000th of an inch in diameter, and possess
the three kinds of cells characteristic of the Nostochinea,
namely, the ordinary cells, the heterocysts, and the sporangia.

The ordinary (figs. 4,5 a, a) cells vary much in length in
different filaments, and sometimes even in the same filament,
and not unfrequently they present evident transverse striae,
which doubtless indicate the commencement of division; the
endochrome is in the form of several oval or irregular granules
in each cell. Under the action of iodine the contents of the
cells assume a dark-brown colour, and separating from the
walls contract towards the centre of the cell, where they appear
bounded by a very definite outline (primordial utricle), fig. 6 a.
The entire filament appeared in some cases to be surrounded
by an indistinct gelatinous (?) sheath.

When the Aphanizomenon first showed itself in the pond,
the heterocysts were abundant; but no sporangia could be de-
tected. The heterocysts fig. 5 6, are in the form of short
cylinders with rounded extremities, and with bluish-green

* On the Nostochinee. By John Ralfs, M.R.C.S., Ann. and Mag. of
Nat. Hist., May, 1850.

APHANIZOMENON FLOS-AQU. 23

contents, which scarcely ever present any trace of granular
structure. Under the action of iodine the following structures,
fig. 6 b, may be seen in the heterocyst :—1. The endochrome
contracted towards the centre of the cell, and presenting a
well-defined boundary. 2. External to this a delicate cell-
wall separated from the contracted endochrome by a transpa-
rent interval, and frequently presenting in its interior, at each
extremity, a minute spherical body, with considerable refrac-
tive powers. 3. An external very delicate, but well-defined
transparent investment.

At first no other kind of cell beyond those now described
could be detected in the filaments, but in specimens gathered
somewhat later many filaments presented in some part of their
course a long cylindrical and slightly-dilated cell, fig. 4 64,
generally about two or three times the length of the hetero-
cysts ; occasionally a single filament presented two such cells.
They correspond to the cells named sporangia in the other
Nostochinee ; their contents are always minutely granular,
and under the action of iodine, fig. 7, separate from the walls
of the cell and contract towards the centre, where they present
avery definite boundary, in which a double outline can some-
times be distinctly seen ; while, external to this, and separated
from it by a clear space, a colourless investing membrane has
become very obvious ; but the second investment, so evident in
the heterocysts, could not here be satisfactorily demonstrated :
the little spherical body visible at each extremity of the cell
of the heterocyst could not be seen in the sporangium. Fila-
ments bearing sporangia were accompanied by those bearing
heterocysts, but whether the two kinds of cells ever coexisted
in the same filament was not manifest.

That the sporangia are not simply enlarged cells, but the
result of the union of several ordinary cells, is highly probable.
The author has succeeded in observing what appears to be
intermediate stages of formation, in which the endochrome of
a group of ordinary cells had already begun to assume the
minutely-granular condition of that of the sporangium, the
septa being, at the same time, evidently in process of disap-
pearing, fig. 8.

When the living plant is collected and placed in a jar of
water, the fasciculi will frequently be seen after some hours
to have broken up into their component filaments, which will
then rearrange themselves in elegant wavy curves parallel to
one another, and forming a nearly uninterrupted stratum on
the surface of the water, fig. 3.

Aphanizomenon Flos-aque, after the death of the plant, is
eminently sensitive to the action of light. Specimens dried on

24 DR. ALLMAN, ON

paper in the shade are of a dull yellowish-green ; but if these
be now exposed to the direct rays of the sun, for about ten
minutes, they will be found to have assumed a bright bluish-
green, which they do not again lose. -

During decomposition in water a fluid is produced, which
is of a claret-red under reflected light, but of a fine grass-green
when viewed by transmitted light.

The next subject to which I would draw attention is a
species of Peridinea, which had just shown itself in such
inconceivable multitudes as to give rise to a peculiar colora-
tion of some of the ponds in the Phoenix Park. During the
last three weeks a spectator on the banks of the large ponds *
in the Park must have been struck by a brown colour assumed
by the water. This colour was sometimes uniformly diffused
through the water ; at other times it appeared as dense clouds,
varying from a few square yards to upwards of 100 in extent.

A microscopic examination of the water proved the brown
colour to be entirely due to the presence of a minute organism,
which, though it does not exactly agree with any published
generic description, I have thought it better, by slightly
modifying the genus Peridinea, as characterised by Ehrenberg,
to place it in that genus rather than construct for it a new
one,

It varies from the 1-1000th to the 1-500th of an inch in
diameter, and approaches in form to a sphere (Plate IIL.,
figs. 9, 10), divided by a deep annular furrow into two hemi-
spheres, on one of which is situated another furrow, springing
vertically from the annular furrow, and terminating at the
pole. ‘The organism under consideration may be regarded as
essentially a solitary cell; it encloses reddish-brown granular
contents, and a large, well-defined central nucleus. In the
midst of the contents are numerous clear spaces, of various
sizes, which, however, appear to be oil-drops rather than true
vacuole.

In most instances a deeper-coloured ocelliform spot was
evident near the polar extremity of the vertical furrow.

It is eminently locomotive, swimming with great activity
by the aid of a flagelliform appendage, which springs from the
vertical furrow near the point of junction with the other, and
of very minute vibratile cilia, which seem distributed over the
surface, and not confined to the furrows, as maintained by
Ehrenberg, in the species of Peridinee described by him.

Before death, and also when only passing from a motile to

* The two large ponds communicate with one another, and together
‘ s ? Beet =)
occupy a space of about 14 acres. The observations were made in June,
1854.

APHANIZOMENON FLOS-AQUE. 25

a quiescent state, most likely preparatory to undergoing some
important developmental change, the contents contract towards
the centre, and then an external transparent and perfectly-
colourless vesicle becomes visible while the flagellum and cilia
disappear, fig. 11. The contracted contents present a very
definite and generally spherical boundary, and are evidently
included in a distinct cell: the resemblance of this internal
cell to the primordial utricle, and that of the external investing
vesicle to the cellulose wall of the vegetable cell, are too
obvious to be overlooked, though the iodine and sulphuric
acid test failed in indicating the presence of cellulose. The
external investing vesicle is non-contractile ; under pressure it
is easily ruptured, and the minutely-granular contents, mixed
with large oil-drops (?), escape upon the stage of the micro-
scope, fig. 12. The nucleus is then easily isolated ; it is of an
uregular, oval form, quite colourless, and marked on its surface
with curved striz, fig. 13.

Individuals were frequently seen undergoing spontaneous
division, which takes place parallel to the annular furrow, and
in the unfurrowed hemisphere, fig. 14. This process appears
to be invariably preceded by a division of the nucleus, and
the author had succeeded in isolating nuclei, presenting almost
every stage of transverse fission, figs. 16, 17.

Believing the species now described to be new, I have
named it P. uberrima.

Since communicating the above facts to the Academy, the
coloration of the ponds has much increased in intensity.
On the 9th of July I again visited them. The colour in
some parts was then of so deep a brown, that a white disc,
half an inch in diameter, became invisible when plunged to
a depth of from 3 to 6 inches, while a copious exit stream,
which constantly flowed away from one of the ponds, pre-
sented the same deep-brown tint. In many places the
Peridinea had descended from the surface, and were found to
be congregated in immense masses towards the bottom, where
they appeared to be quite healthy, though presenting the con-
dition described above as characterising the quiescent state of
the animalcule. It is highly probable that this contracted
condition of Peridinea—a condition, however, which must not
be confounded with the encysting process observed in many
infusoria—is connected with reproduction. <A field of much
interest is here open for investigation, but I was unfor-
tunately at this point obliged to discontinue my obsery-
ations.

26 OKEDEN, ON THE DIATOMACEOUS DEPOSITS OF

On the Deer Diatomaceous Deposits of the MupD of Miz-
FORD HAvEN and other Locauities. By FITzMAuRIcE
OKEDEN, C.E.

Art the time that Mr. Roper’s interesting paper on the
Thames mud appeared, I was myself engaged in examining
the mud of Neyland, which is a creek of Milford Haven and
the terminus of the South Wales Railway. At this time, also,
we were engaged in making borings for engineering purposes
to ascertain the depth of the mud in this creek, and in some
places we found that it exceeded 40 and even 50 feet.

It struck me that it would be interesting to ascertain
whether the mud at these great depths was as rich in diato-
maceous remains as the surface had proved to be in the living
specimens. I accordingly had constructed a simple, but I
think effective, apparatus, for the purpose of obtaining the
genuine mud from any depth that might be reached, and of
insuring that it should be unmixed or uncontaminated with
any other deposit. I will, therefore, before laying the results
before the reader, describe the apparatus made use of. |
must premise that the usual “ boring” apparatus employed
for engineering purposes consists essentially of any number of
iron rods, which screw one into the other; to one of these is
screwed an auger or a chisel-point, as the case may require.
This is inserted into the ground to be tested, and worked
round by manual force and downward pressure, length after
length of rod being added as the ground is penetrated. In
addition, then, to this apparatus, I obtained, first, several
lengths of wrought-iron gas-pipe, about an inch in diameter,
and each screwing into the other, and also a similar number of
iron rods, each a few inches longer than the lengths of gas-
piping, and each also screwing into the other ;
to the end of one of these lengths of rod is
attached a cork of the exact diameter of the
gas-pipe, or a trifle larger. This cork is fixed
by a washer and nut, as shown in the sketch.
The gas-piping should be in lengths of about
8 feet each, as this is the most convenient in
work : one of these lengths should also be again
divided into two parts, which must, however,
screw and unscrew ; and this length is to be the
one first put into the ground or mud, for reasons
which I will presently explain.

The mode of proceeding is as follows: First,
a hole is bored to the required depth—say 20
feet—with the usual boring apparatus; this done, the appa-

THE MUD OF MILFORD HAVEN. 27

ratus is drawn out, the jointed length of gas-pipe is now
introduced, the end of it with the rod to which the cork is
attached having been previously stopped, the rod passing up
the centre of the gas-pipe; this is let down the hole, another
length of pipe being attached, and another length of rod, and
so on, length after length of pipe and rod, until the bottom
of the hole is reached. We shall thus have a continuous
length of gas-piping, which will be penetrated by a con-
tinuous length of iron rod attached to the cork at the end of
the pipe. It is obvious that this cork will entirely prevent
any foreign matter from entering the gas-pipe. Having thus
reached the bottom of the hole, now pull up the cork into
the gas-pipe about 4 feet, by means of the rod attached to it,
and then press the whole apparatus into the soft mud. The
pressure will now drive the mud up into the pipe as far as
the cork is drawn up; now remove the whole apparatus, and
by means of the rod push the cork back again to the end of
the last length of pipe, when the charge of mud will be
driven out in the form of a sausage, and, by rejecting the
two ends of it, and taking only the middle piece, we may
be perfectly sure that the mud at that depth, and that only,
has been obtained.

Having secured the prize, the short length of piping which
contained it is now to be unscrewed, and carefully washed with
a common gun-cleaning rod and some tow, when it is ready
for another experiment.

With this apparatus, then, I have penetrated Neyland mud
in various places to depths of 20, 30, and 40 feet; and the
results have been so interesting, and the deposits have proved
so rich in Diatomaceous remains, that I have been tempted to
put some of the results upon paper.

The first trial I made was at a depth of 20 feet; and a
careful examination of this deposit, when well cleaned, and
the coarse sand thoroughly separated, gives us a list of the
following forms :—

Fyesh-water Species.

Epithemia alpestris. Pinnularia viridis.
Campylodiscus costatus. 5 radiosa.
Surirella biseriata. Me major.

Navicula ovalis. Gomphonema geminatum, g.

Marine, or Brackish.

Cocconeis scutellum, (a). | Coscinodiscus eccentricus.
mt , a | ne Ocellus iridis.
55 35 ; | Actinocyclus undulatus.
5 Grevillii. | 3 sedenarius.

Coscinediscus radiatus. Triceratium favus.

28 OKEDEN, ON THE DIATOMACEOUS DEPOSITS OF

Triceratium comptum ? | Navicula liber.
$3 alternans. | Pinnularia cyprinus.
es armatum, n. sp. FS distans.
Eupodiscus sculptus. | As peregrina.
Campylodiscus Hodgsonii. | Stauroneis pulchella.
5 cribrosus. Pleurosigma formosum.
* parvulus. Rf angulatum.
Surirella ovata. 45 Balticum.
3 fastuosa. an tenuissimum.
a lata. Synedra superba.
Tryblionella marginata. Doryphora amphiceros.
is punctata. Achnanthes brevipes.
3 acuminata. Rhabdonema minutum,
os scutellum. 5 arcuatum.
Nitzschia sigma. Grammatophora serpentum.
Amphiprora constricta. Amphitetras antediluviana,
Navicula Jennerii. Isthmia enervis.
i didyma (a). Biddulphia aurita.
4 AG Oe 5 rhombus.
a po GY quinque-oculus, Kutz.
fe punctulata. Podosira maculata.
an convexa. Melosira sulcata.
‘s elliptica. 4 Borreri.

», palpebralis. Dictyocha speculum.

I have also two fine specimens of what I thought to be a
new Navicula; but on referring them to Mr. Sm he in-
formed me that it had been already observed by Mr. Hennedy,
and it has been named NV. Hennedii by Mr. Smith. It was in
this deposit that I found the first specimen of the Triceratium
which has been described and named by Mr. Roper as T.
armatum.

The prevailing form, however, is the Navicula Jennerti,
which is extremely abundant. The specimens of Coscino-
discus are also magnificent and abundant. "

Of the Triceratia, T. favus, and T. comptum (?) are very
abundant. ‘T. alternans occurs but sparingly.

The beautiful valve of Actinocyclus sedenarius, described
by Mr. Roper in his paper on the Thames mud, occurs but
sparingly; all the other forms in the foregoing list are
tolerably abundant, and occur also in the 30 and 40 feet
deposits.

T. favus occurs also pretty frequently at both these depths,
while in the 30-feet deposit I found a most curious and in-
teresting form, of which I have sent specimens. Mr. Smith
cites me it is the Cerataulus turgidus of Ehrenberg, and
will be the Biddulphia turgida of Mr. Smith’s second volundes
I am not aware that it has been hitherto figured or described
by any one as a British species.

But it is not always necessary to resort to the boring
apparatus to obtain material for investigating these deep

THE MUD OF MILFORD HAVEN. 29

deposits. Wherever excavations for building or other pur-
poses are going on near the banks of a tidal river, there will
be found an ample field for the industrious observer.

At Swansea, for instance, where some docks are now being
constructed, I have obtained some rich samples of Diatoma-
ceous clays.

The strata through which these excavations are being made
occur in the following order :—

Feet

Gravel and sand : Bag)

D Clay : : co
Peat 3 : Ser:
Sandy clay 4

D Clay : - Be!
Peat , 5 : ‘ 1
Clay ‘ 5 : ap eee
Total ‘ Se)

The lowest bed of this clay, at 25 feet depth, is literally
“swarming”’ with Epithemia musculus and Surirella striatula :
other marine forms are abundant; while the fact of fwo beds
of peat lying above it shows its extreme antiquity. The
other two beds of clay above it, marked D D, are also rich in
Diatomaceous remains. I have not yet had time to examine
these deposits thoroughly, so as to make lists of the forms
occurring in them; but a comparative examination of the
three beds would be highly interesting, and I hope to be able
to prepare one for the next number of this Journal.

Again, from a brick-yard near Carmarthen, which is now
upwards of a hundred yards from the present banks of the
river (the Towy), and at a depth of about five feet below the |
surface of the ground, I have obtained a sample of the old
tidal deposit which now forms the brick-earth, and which is
full of the most magnificent specimens of 7'riceratiwm favus
and Coseinodiscus that I have ever seen; while the beautiful
Actinocyelus sedenarius, with its sixteen septa, is of common
occurrence.

From the foundations of a bridge we are now building
over the Cleddan near this town (Haverfordwest), I have also
obtained a rich sample of clay at a depth of about 10 feet,
and at about 20 feet distance from the present bank of the
river. In this sample the fresh-water forms occur more fre-
quently than in the other deposits. This might be expected,
as the tidal influence does not extend very far above this
point.

I could enumerate many other instances which have come
under my notice, but it would be only a repetition of the

30 ON A POST-TERTIARY LACUSTRINE SAND,

above facts: indeed, I have rarely tried a sample from any
of these clays, either near a fresh or brackish stream, in which
a careful washing would not eliminate abundance of Diatoma-
ceous remains. Of course, some will be richer than others,
but I have found them in all. Let it not be thought that too
enthusiastic a view has been taken of the subject. I have
sent a set of slides illustrative of all the above-mentioned
deposits to the Editors of this Journal, and I think they will
bear me out in the assertion that neither their richness nor
their interest has been overstated.* -

From these facts it appears that not the surface merely,
but the whole mass of these tidal deposits, is penetrated by
these minute and wondrous organisms; while from the fact
of their being found at Neyland at a depth of 40 feet below
the present surface, and close upon the rock which forms the
original bed of this estuary, the mind is irresistibly led to the
conclusion that they have existed there from the time when
the waters first rolled over the spot, when silence and soli-
tude reigned supreme where now resounds the “ busy hum”
of the hundreds who are employed in bringing one of the
great arteries of commerce and civilization to its ocean home.

In making out the list of the forms in the Neyland
deposits, [ have carefully abstained from inserting the names
of any but those which I could identify with certainty, either
from Mr. Smith’s work or from information furnished to me
by Mr. Roper, to whose kind assistance I am deeply indebted
during the time I have been studying the subject. Being but
a beginner in the study, I thought this the best plan to adopt;
but Iam sure, from what I have observed, that were these
deposits well examined by other and more experienced inves-
tigators than myself, the list might be far more extended, and
many new forms brought to light. Still, if I shall have been
the means of drawing attention to the subject of these deep
deposits, or of extending in any way, however small, the
boundaries of this interesting field of research, I shall feel
amply recompensed for any trouble I have taken in this
matter.

On a Post-Tertiary Lacustrine Sanp, containing Diatroma-
crous Exuvia, from Glenshira, near Inverary. By Wit-
uiAM Gregory, M.D., F.R.S.E., Professor of Chemistry.

Tuis remarkable deposit was sent to me in February last by

the Duke of Argyll, who had found it in the valley of Glen-

* The slides sent us by Mr. Okeden are uncommonly rich in the various
forms of Diatomacece.— Eps.

CONTAINING DIATOMACEOUS EXUVIZ. 381

shira, the waters of which flow into Loch Fine, well known
as a sea-loch, at its upper part. The sand occurs above a mile
from the mouth of the valley, lying under a considerable
depth of good alluvial soil. It is nearly black, with shining
particles of mica, and very dense. It consists chiefly of the
detritus of the surrounding mountains, formed of micaceous
schist, and contains therefore much quartz and mica. There
is also a considerable proportion of an iron ore, and of a dark
matter of vegetable origin, and apparently somewhat of a
peaty character. To the last-named ingredients the dark
colour of the sand is due.

On placing a little of it under the microscope, I noticed one
or two Diatomaceous forms, such as a Navicula didyma, a
Cocconeis scutellum, and a Synedra radians. But the propor-
tion of these was so small that without some purification
nothing could be done. After various trials, I found the fol-
lowing plan to yield tolerably satisfactory results.

The mass was first warmed, and when the violence of the
action had passed, boiled, with the most concentrated nitro-
muriatic acid. This not only dissolved the iron ore, but
completely removed the dark organic matter, and left a sand
of a pale-yellowish colour, in which the Diatomes were more
easily seen.

The next step was to remove, by subsidence in water and
decantation, the greater part of the quartz and all but the
finest and lightest scales of mica, which, having much the
same density as the shells, could not be got rid of. Any
attempt to push the process farther caused a loss of shells.
The residue thus obtained was now found to be rich in Dia-
tomes ; and when mounted in Canada balsam, the mica became
so transparent as not materially to interfere with the exami-
nation of the shells. The entire residue did not exceed 1-20th
of the original sand, and the Diatomes formed only from 1-5th
to 1-3rd of the residue, so that they could not have amounted
to much more than 1 or 2 per cent. of the mass.

It will be seen from this, that the Glenshira deposit is of
an entirely different character from those earths in which
Diatomes have usually been found in the fossil state, such as
the Raasay or Mull deposits, which consist entirely of Diato-
maceous shells. On the other hand, it presents all the cha-
racters of a lacustrine or estuarial deposit or mud, such as the
Thames mud, or similar deposits now forming in estuaries or
lakes. Of course the predominant mineral ingredients are
such as are yielded by the adjacent rocks, and the Diatomes
have merely been deposited in small proportion along with
these. We shall see that there is a very remarkable analogy,

32 ON A POST-TERTIARY LACUSTRINE SAND,

as far as concerns the Diatomes present, between this sand
and the Thames mud recently described by Mr. Roper in the
second volume of the “ Journal.”’

The first glance at the Glenshira sand under the micro-
scope leads to the observation, that, like the Thames mud, it
contains both marine and fresh-water forms. In this respect
it resembles the deposit or mud of all estuaries. From its
position, however, there is every reason to conclude that it
was formed in its present locality, when that part of the valley
was occupied by a fresh-water lake, which is now confined to
the lower part of the valley, but has evidently extended much
higher in former periods. The question of course naturally
occurs, whence came the abundant marine forms? But this
is easily explained, if we attend to what is going on in the
present small fresh-water lake. The level of this lake is pre-
cisely that of half tide, so that at high water the sea flows
into it, while at ebb tide the water of the lake runs into the
sea.

This remarkable state of matters produces a mixture, in the
lake, of fresh-water and marine forms, both animal and vege-
table. The Duke of Argyll mentions, that nets, thrown for
salmon in the lake, have been drawn up full of herring ; that
other marine animals occur in it, and that marine alge are
also found, dwarfed by the influence of the fresh water.
Having been supplied with some of the deposit or mud now
forming in the lake, I examined it, and found it very closely
to resemble the sand from the higher level, save that the pro-
portion of organic matter was considerably greater. But, like
the older sand, it contains both marine and fresh-water
Diatomes, and these belong in many instances to the same
species. I have noticed some difference in the relative pro-
portions of species, and I shall take an opportunity of care-
fully studying the recent deposit or mud of the lake; but in
the mean time I can state, that in all essential characters the
recent deposit agrees with the fossil one.

From these facts it may be inferred that the lacustrine sand
of Glenshira, which I refer to the post-tertiary period, on
the authority of the Duke of Argyll and of Mr. Smith of
Jordanhill, both of whom are familiar with the localities, was
formed in the lake when that lake occupied the part of the
valley where the sand occurs, and that the relative levels of
lake and sea were then the same as now. ‘This seems to be
the simplest mode of accounting for the abundance both of
fresh-water and of marine forms. Had the sand been depo-
sited in sea water, it could not have been, as it is, extremely
rich in fresh-water species, and there is no reason to suppose

CONTAINING DIATOMACEOUS FEXUVI®. 33

it to have been formed in an estuary, like the Thames mud,
when we see a similar deposit in course of formation at the
present hour in the fresh-water lake, not much more than a
mile from the spot.

But if this be admitted, then it must also follow that, since
the relative levels of sea and lake were the same then as now,
and since the sand occurs at a considerably higher level than
that of the present lake,—it must, I think, follow, that the sea
has fallen, or the land has risen, since the period when the
sand was deposited. This is a conclusion at which geologists
have arrived in many instances, from other phenomena, such
as raised beaches, as, for example, in the Clyde, with which
Loch Fine communicates. It is interesting to find the study
of the Diatomaceous forms, occurring so scantily in this de-
posit, assisting to throw light on one of the questiones vexrate
of geology.

I have said that the Diatomes are but scantily diffused in
the Glenshira sand; and this is true, since they do not much
exceed 1 per cent. of the mass. But when we examine the
putified or cleaned residue, in which they are, as it were,
concentrated, we are struck at once with the very large
number of species present.

In this respect the Glenshira sand far surpasses every de-
posit hitherto described, even that of Mull, in which I have
found 150 species, and the Thames mud, in which Mr. Roper
detected 104 species.

In the Mull deposit all the species, with a very few excep-
tions, and these so rare as to be evidently accidental, derived
from the proximity of the sea, and possibly carried by the
winds, belong to fresh water. But in the Thames mud and
in the Glenshira sand, as already stated, both classes of forms
occur abundantly. It is this which accounts for the large
number of species. Up to the present time I have recog-
nised in the latter not less than 240 species, and I am quite
satisfied that a good many remain to be identified. Judging
from what has ‘been done already, | cannot doubt that the
number of species will, before long, amount to at least 250.

In consequence of the circumstances under which it has
been formed, this deposit does not contain any one or more
greatly predominant form, as is generally observed to be the
case in deposits formed where the Diatomes grew and died.
As they have all been transported by water, they constitute,
when the quartz, mica, and other matters eee separate fed
are removed, a mixture of a very remarkable kind, in which
a large number of forms are tolerably abundant, and a still
larger number are pretty frequent, while none are so pre-

VOL. III. D

34 POST-TERTIARY LACUSTRINE SAND

dominant as we find them in recent gatherings, and a good
many are so scarce, that we have often to search long before
finding additional specimens, although with patience we
generally succeed in doing so.

The peculiar constitution we have described renders a com-
plete study of this deposit a work of much time and labour.
I soon found that it was only by pursuing the minute and
systematic mode of search which I have described in my
account of the Mull deposit, that I could hope to determine
the species present in this one. I have found it, however,
advantageous, in consequence of the large number and relative
scarcity of new forms in the Glenshira sand, to adopt the plan
of marking any striking forms, or such as require to be ex-
amined, or are to be figured, when first observed. I find the
best way of marking is, after fixing on the form, to put on
the 2-3drd objective, and under that power to place one spot of
ink just above, but not on, the form. This is much more
rapidly and easily done than drawing a circle round it, and
it interferes much less with the remaining forms. A note 1s
kept of all the spots made on each slide, arranging them in a
certain order, according as they follow in the regular course
of sweeping the slides. By this means any marked form is
instantly recovered ; and I have been able to place in the
hands of Mr. West, in the course of one forenoon, a number
of new and striking forms so great, that without some such
method I could not have pointed them out, from their com-
parative scarcity, under a much longer time.

It may be here mentioned, that, in studying a mixture like
the present, no examination, short of a thorough and minute
search, would suffice. Without this we should infallibly miss
a large proportion of the most interesting forms. To give
some idea of the necessity of this, | may state that I have
found it necessary to explore, minutely and repeatedly, 60
well-filled slides of this deposit, and that I have not yet ex-
hausted it, as even now I hardly ever search one of these
slides without observing something new or interesting pre-
viously overlooked.

This is no doubt very laborious, but without labour nothing
can be well done, and in the present case the results have been
highly satisfactory. Ihave recognised upwards of 200 known
species, while a number remain that for the present I cannot
exactly name, for want of good figures; and besides this, I
have distinguished about 25, probably more, new and un-
described forms, most of which are very interesting. Such is
a general account of the results obtained ; and after these pre-
liminary remarks I shall now proceed to the details. I shall

CONTAINING DIATOMACEOUS EXUVIA. 35

first give the list of known species, under the two heads of
marine and fresh-water forms, as Mr. Roper has done in the
case of the Thames mud; and I shall then briefly describe the
new species, which will also be figured. But as circumstances
have rendered it impossible for me to have more than one
plate in the present number of the ‘ Journal,’ [ am compelled
to reserve one-half of the figures till the next number.

It is proper to explain that I shall have to mention several
new forms, as occurring in this deposit, which I do not figure,
although no figures fae as yet appeared of them. The reason
is, iat these eae have been recently observed by others,
prior to me, and it is to be presumed that the first observers
will take an early opportunity of describing and figuring
them. I propose to figure all such forms as are now, for the
first time, distinguished by myself, and also some striking
varieties of known species, in which the Glenshira deposit is
uncommonly rich, Without further preamble, let us now
proceed to the list of known forms.

I. Marine Species,
including such as occur in both sea water and brackish water,
as well as those which seem to belong to brackish water more

especially :—

1. Epithemia Musculus. _ 22, Amphipleura sigmoidea.
2. Amphora affinis. | 23. Navicula Liber.

3 7 tenera. | 24, $5 Smithii.*

4, = costata. | 25. rs Jenneri.

5. Cocconeis Scutellum. 26. 3 convexa,

6. 33 Grevillii. 27. Bs elegans.

7. Coscinodiscus radiatus. 28. 3 palpebralis.
8. + excentricus. 29. rf punctulata.
9. Eupodiscus crassus. 30. ee pusilla.
10. - Ralfsii. bl. $ Didyma.

11. Campylodiscus parvulus. 32. a nitida. ft

12. Surirella fastuosa. 35. eranulata, Bréb.t
13. 3 constricta. 34. Pinnularia directa.
14. Tryblionella punctata. 35. i Cyprinus.
15% As acuminata. 36. 5 peregrina.
16. Nitzschia Sigma. | 37, Stauroneis pulchella,
Ne x angularis. | 38. . salina.
18. o birostrata. 39. Pleurosigma formosum.
19. Amphiprora alata. 40. ; angulatum.
20. 53 constricta. 41. 5 Balticum.
21. ae vitrea. 42. ae strigosum.

* N. elliptica, W.Sm. M. de Brébisson has given this name, on account
of the term ‘ elliptica’ having been long applied to another species by
continental writers.

+ This is a beautiful new species, to be figured in vol. ii. of Mr.
Smith’s ‘ Synopsis.’

t Also a very fine new form. Prof. Arnott finds it in the Clyde.

dp 2

36 POST-TERTIARY LACUSTRINE SAND

43. Pleurosigma rigidum. 56. Biddulphia aurita.
44, Synedra superba. 57. Melosira Borreri.

45, + acicularis. 58. ne sulcata.

46. Gomphonema marinum. 59. Orthosira nummuloides,
47. Achnanthes longipes. 60. Podosira hormoides.
48. 5 brevipes. 61. #3 maculata.
49. oe subsessilis, 62. Bacillaria paradoxa.
50. Rhabdonema arcuatum. 63. Dictyocha Speculum.
51. : minutum. 64. 35 gracilis.
52. Zygoceros Surirella.* 65. rf Fibula.
53. Grammatophora marina. 66, ag trifenestra.
54. serpentina. 67. Schizonema Crux.

55. Amphitetras antediluvianum.
Total, 67 marine species.

Il. Fresh-water Species,

including such as occur in both fresh and brackish water :—

1. Epithemia Hyndmanni. 34. Cyclotella operculata.
2 ‘ turgida. 30. 5 rotula.
3 3 gibba. 36. Campylodiscus costatus.
4 e Argus. 37. bicostatus.t
5 53 Zebra. 38. Surirella minuta.
6 - Westermanni. 39. pinnata.
U 4 rupestris. 40, * ovata.
8 5 Sorex. 41. 5 Brightwellii.
9 #3 proboscidea. 42, sf Crumena.{
10 3 alpestris. 43. Tryblionella marginata.
11. s longicornis. 44, Cymatopleura Solea.
12. 3 constricta. 45, Nitzschia sigmoidea.
18. Cymbella Ehrenbergii. 46, BH minutissima.
14 5s Helvetica. 47. 5 acicularis.
15 a Scotica. 48. a linearis.
16 ; maculata. 49. +. amphioxys.
ie 33 affinis. 50. 3 vivax.
18. A cuspidata. 51. Amphipleura pellucida.
19. Hunotia Arcus. 52. Navicula rhomboides.
20. Be monodon. Des i ovalis.
21. 6 diodon. 54, Mi minutula,
22. 3 triodon. 55. Ba firma.
23. + tetraodon. 56. 35 affinis.
24, ‘i bigibba. 57. % amphisbena.
25. 55 Camelus. 58. 35 crassinervia.
26. oy incisa. 59. BS lanceolata.
27. p depressa. 60. . gibberula.
28. Amphora ovalis. 61. 3 angustata.
29. i minutissima. 62. a Semen.
30. Cocconeis Pediculus. 63. Pinnularia major.
bl. PA Placentula. 64. 53 viridis.
32. 3 Thwaitesii. 65. - lata.
38. Coscinodiscus minor. 66. an acuta.

* Figured by Mr. Roper in No. VII. of the ‘ Journal.’

+ Figured by Mr. Roper, loc. cit.

+ A new fresh-water species, first distinguished, I believe, by Professor
Walker Arnctt.

CONTAINING DIATOMACEOUS EXUVIA&. 37

67. Pinnularia radiosa. 105. Gomphonema dichotomum.
. BA oblonga. | 106. . Fusticulus.+

69. Be divergens. | LOG: ¥ insigne.}

70. A gibba. 108. Meridion circulare.

wil) = gracilis. jeeL093 . constrictum.

72. a viridula. _ 110, Achnanthes exilis

73. if mesolepta. _ 111. Achnanthidium lanceolatum.

74, fn stauroneiformis. | 112. 55 coarctatum,

75. a latestriata.* Bréb.

76. Ys undulata.* 113 Himantidium majus.

Ce 3 tenuis. * 114. A Arcus.

78. - parva.* } dlaesy: 3 pectinale.

79. exioua.* ) iG: 5 eracile.

80. Stauroneis Pheenicenteron. ION AS bidens.

81. Bs gracilis. 118, Fragillaria capucina.

82. ca anceps. iG). 4 virescens.

83. 3 dilatata. | 120. Odontidium mesodon.

84, 5 punctata. 121. 55 mutabile.

85. rectangularis.* 122. Bi Tabellaria.

86, Pleurosigma attenuatum. 123. Harrisoni.§

87. Synedra Ulna. 124. Denticula tenuis.

88. bs radians. 125. ss sinuata,

89. cs pulchella. | 126. Tabellaria fenestrata.

90. ‘5 obtusa. DT. 55 flocculosa.

oie Bs biceps. | 128. % ventricosa.

$2. » lunaris. | 129. Diatoma vulgare.

93. acicularis. | 130. elongatum.

94. Cocconema lanceolatum. | 1381. Melosira varians.

95. 5 Cistula. . 132. Orthosira arenaria.

96. cymbiforme. 133. + nivalis.

97. 4 gibbum. | 134. Mastogloia elliptica.

98. Gomphonema geminatum. 135. Dansei.

gS). a acuminatum. | 186. Colletonema neglectum.
100. 3 coronatum. ) UeiTe 7 vulgar e.
101. is curvatum. | 1388. 5 subflexile.
102. ‘, constrictum. 139. Encyonema prostratum.
103, 3 capitatum. | 140. 3 ceespitosum.
104, 5 tenellum.

Total, 140 fresh-water species, which, added to 67 marine
forms, gives a grand total of 207 species, known as British.
To these must be added a few which have now, for the first
time, occurred in this country, though known on the Continent.
Such are—
208. Navicula nodosa,|| Kiitzing.

209. Pinnularia pachycephala, Rabenhorst.
210. 56 (Navicula) Gastrum,** Ehr.

* These six species are figured in my account of the Mull deposit.

t This species has lately been distinguished by Mr. Smith.

{ A new species, which I shall describe and figure in the next number
of the ‘Journal,’ along with several other recent forms, which I have
observed during the past year.

§ A beautiful form, lately detected by Mr. Harrison.

|| To be figured in the next number of the ‘ Journal.’

SI Occurs also in the Mull deposit, and will be figured in next number.

** This form is figured in the present paper. See fig. 20.

38 POST-TERTIARY LACUSTRINE SAND

We have thus in the Glenshira sand 210 known and de-
scribed species, with the exception of one or two recently
observed and likely to be soon figured. But I feel quite
assured that there are a good many more, belonging to this
category, which I am unable clearly to identify, from the
want of good figures, especially in those genera to be figured
in vol. ii. of Mr. Smith’s Synopsis. In particular, there
appear to be several discoid forms of the genera Melosira and
Orthosira, &c., which will be found to be of known species.

Let us now turn to those forms which appear to be un-
described, of which the proportion is unusually great in this
deposit. It has been already mentioned that only about one-
half of these forms can be figured on the accompanying plate,
and that the remainder will be given in the next number of
the ‘Journal.’ It will probably be best to describe the forms
here figured as they occur on the plate, in which the order of
the Synopsis is followed. It must be borne in mind that some
of the figures represent varieties of known forms, and that the
two first belong to the two new forms observed by me in the
Lillhaggsjon fal Liineberg deposits, and described in last
number of the ‘ Journal.’

Fig. 1, Plate IV., shows two forms of Hunotia Falz, W.
G. This very remarkable form needs no farther descrip-
tion beyond what will be found in the ‘Transactions of the
Microscopical Society,’ vol. 11, p. 105. It has not yet oc-
curred as a British form. It occurs with fresh-water species.

Fig. 2 represents an example of Mitzschia Siqgmatella,
W.G., also observed in the two deposits just named. But
it occars, as I have formerly stated, in the Mull deposit also ;
and since describing it I have found it, not only in the sand
of Glenshira, but also in a recent gathering from Elchies, in
Banffshire. It is therefore a British species, and, from the
Banffshire locality, belongs to fresh water. (211.)

Fig. 3. Cymbella truncata, W.G. This pretty and well-
marked species occurs in the Mull deposit, but sparingly. It
is frequent in the Glenshira sand, and cannot, I think, be
referred to any of the species of Cymbella_ or Cocconema,
figured by Mr. Smith. Of course it is impossible, in a fossil
deposit, to ascertain whether it be really a Cymébella, that is,
free, or a Cocconema, that is attached by a stipes. It is pos-
sale and even probable, that this species has been noted on
the Continent, but I have not been able to see any figure with
which it can be safely identified. It is very uniform in its
characters, always exhibiting the truncate or square ends from
which I have named it. i is sometimes a good deal longer
than the figure here given, which may be taken as typical.

CONTAINING DIATOMACEOUS EXUVIA. 39

It is a fresh-water form, and I have found it in many recent
gatherings. (212.)

Fig. 4. Amphora Arcus, W.G. This fine form has not
occurred in its entire state, but is frequent in the detached
condition. The halves have precisely the form of a strung
bow, often very elegantly curved. The striz are coarse and
moniliform. I have no certain means of ascertaining its
habitat, but I suspect it to be marine. (213.)

Fig. 5. Amphora incurva, W G. This is also a very pretty
form, most probably marine, and occurring detached, like the
lust. The strize are very much finer than in A. Arcus. (214.)

Fig. 6. Amphora angularis, W.G. This is a striking form,
and unlike the two preceding it occurs now and then com-
plete, when it exhibits short square apices. It has a slight
constriction in the middle. Habitat unknown. (215.)

Fig. 7. Cocconeis transversalis, W.G. This neat little form
is distinguished from the other species of the genus by having
fine transverse striz. Its form is a pure oval. Habitat not
known. (216.)

Fig. 8. Cocconeis speciosa, W.G. This form is nearly allied
to C. Scutellum, but is usually smaller, and has somewhat of
an angular form. The chief distinction lies in the stria, which
are much less numerous than in C. Scutellum, not exceeding
12 in 001", and they are formed of much fewer and much
larger granules. Like C. Scutellum it occurs both with and
apparently without a margin; and it might be taken for a
variety of that species, but for the number and peculiar
character of the striz. I have closely searched several slides
of marine origin, full of Cocconeis Scutellum of every degree
of development, but I have not found in them one example of
C. speciosa. 1 therefore regard it as a distinct species. (217.)

Fig. 9. Cocconeis distans, W.G. This very beautiful form
is at once characterised by the equal size of the dots or gra-
nules, and their great distance from each other, so that it almost
loses the aspect of striation, The form is purely oval. (218.)

Fig. 10. Cocconeis costata, W.G. This is a fourth new
species of the genus, and is at once characterised by its very
strong and entire cost, which seem to be double lines or
bands, expanding a Jittle externally. It is a perfectly well-
marked species. The habitat of this, as well as of the two
preceding forms, is unknown, but they are probably of marine
origin. (219.)

Fig. 11. EHupodiscus, qu? Ralfsit 8. ‘This disc, which is
not unfrequent, has a finely-radiate surface, the radii composed
of small puncta, as in #. Ralfsi7. But there is no trace of the
peculiar blank spaces among the rays, which, so far as I know,

40 POST-TERTIARY LACUSTRINE SAND

appear to be characteristic of EL. Ralfsti. This latter species
occurs with the usual characters ; and I am inclined to regard
the form, fig. 11, as distinct, but do not venture to give it as
a species without further investigation. It is, in all proba-
bility, a marine form.

Fig. 12. Surirella fastuosa 8. This species is finely deve-
loped, insomuch that it might almost be taken for a distinct
species. I am disposed, however, to regard it only as a finely-
developed S. fastuosa, as figured by Smith, and probably more
truly typical than the form he has figured. It agrees well,
except in being larger, with Kiitzing’s figure. It is known to
be a marine species.

Fig. 13. Tryblionella constricta, W.G. This pretty little
form is very frequent in the deposit. Its form is that of
Cymatopleura apiculata, but it is very much smaller, and has
all the characters of Tryblionella. Strie transverse, fine, but
distinct. I arm informed by Mr. West, that he long ago met
with it in gatherings from Poole Bay. It is a marine form.
(220.)

Fig. 14. Amphiprora vitrea, 8? This fine form is frequent
in the deposit. The peculiar arrangement of the median line,
with its double curvature, at once strikes the eye. Indeed, on
comparing it with the figure of A. vitrea, in the ‘Synopsis,’ it
might be supposed to be a distinct species. But in the mean
time, and until further examination, I refer it to the species
named. It is a marine species.

Fig. 15. Navicula birostrata, W.G. This is a well-marked
species. Form elliptical, witi contracted, slightly produced,
somewhat truncate apices. Strive fine, somewhat inclined. It
appears to vary a good deal in size. Habitat unknown. (221.)

Fig. 16. Navicula rhombica, W.G. This beautiful form
is frequent in the deposit. Its form is rhombic, varying from
short and rather broad, with obtuse apices, to long and narrow,
with acute apices. Strie very fine, transverse, quite distinct,
even in balsam, which at once distinguishes it from WV. rhom-
boides. The median line and central nodule are also quite
different ; and, in consequence, it differs totally in aspect from
N. rhomboides, which is also present in the deposit, and with
which it cannot be confounded. Habitat not known. (222.)

Fig. 17. Navicula gastroides, W. G. This form, when
small, has some resemblance to N. pusilla; but is of much
stouter habit, and has a brown colour, even in balsam. Besides
this, it occurs much larger, being then more elliptical, while
the smaller individuals are often almost orbicular. Striz
radiate and inclined. The median line and central nodule are
very strongly developed, and the short apices appear as the

CONTAINING DIATOMACEOUS EXUVI. 4]

truncate extremities of the broad median line. Its habitat is
not certainly known. (223.)

Fig. 18. Navicula crassa, W.G. This is a fine and well-
marked species. Form elliptical, with a very slight inflexion
before the obtuse apices. It varies considerably in size; has
a very stout habit, and a brown colour in balsam. There is
a large round spot in the centre, within which the two halves
of the median line terminate in small round knobs, but do not
meet. Striz transverse, very fine, but distinct, not quite
reaching the central line. It is frequent in the deposit, and is
probably a marine form. (224.)

Fig. 19. Navicula maxima, W. G. This is a fine large
form, much less frequent than any of the preceding. Form
linear, elliptical, broad, with obtuse extremities. Strie fine,
transverse, reaching the central line. ‘There seems to be a
variety which is longer and narrower. Habitat unknown.
(225.)

Fig. 20. Pinnularia (Navicula) Gastrum, Ehr. This little
form is new to Britain, having been found by Ehrenberg in
Mexican and North American gatherings. It is short, broadly
lanceolate, with obtuse extremities slightly constricted: Striz
distinct, strongly radiate. The habitat is not given in Kiitz-
ging, fet ais probably marine. (226.)

Fig. 21. Pinnularia apiculata, W. G. This is another
well-marked little species, which is not rare in the deposit.
Form linear, narrow, contracted to small truncate apices.
Striz distant, transverse, hardly reaching the median line.
Habitat unknown, (227.)

Fig 22. Synedra Vertebra, W. G. This form, which is
very frequent in the deposit, belongs to the same division as
S. pulchella and S. acicularis. It differs, however, from both
these forms, which also occur in the deposit, a antl can thus
be compared with it, in the remarkable relative width of the
central portion, which has a somewhat curved outline, and
the equally remarkable way in which it suddenly contracts to
the very slender terminal portions. In the largest specimens,
these are very long. Its form resembles that of certain ver-
tebree, and it has been named so as to recal this resemblance.
Nodule strongly developed. Strie very fine. The habitat of
this species is unknown, (228

Fig. 23. Synedra undulans, W.G. This is, perhaps, the
most remarkable of all the forms in the Glenshira sand. It
is exceedingly elongated, and so slender that a_ perfect
specimen has not yet occurred to me. It consists of a middle
portion rather wider than the rest, tapering both ways to a
very small width. From this point it extends on both sides,

42 POST-TERTIARY LACUSTRINE SAND

for a long way, of uniform width, and terminates in small
oval expansions. The narrow part has strong moniliform
striae, which, in the central and terminal expansions, are
resolved, except just at the margin, into a general granulation.
The margin is undulated, except for a short distance from
each apex. It will be seen by one of the figures, which is
not so long as some are, that the narrow part, on one side,
without any part of the central long expansion, is frequently
so long as to extend the whole way across the field, with a
power of 400, that is, probably, 1-50th to 1-40th of an inch.
This would make the length of the entire form to be probably
from the 1-20th to the 1-15th of an inch, or more. This, with
its extreme tenuity, accounts for its not occurring entire in a
deposit carried by water, where it must have been constantly
agitated. I have been informed by Mr. West, that a similar
form, possibly of the same species, although shorter, occurs in
a gathering from Port Natal, in the hands of Mr, Shadbolt.
This curious Synedra is, therefore, a marine form, and I
anticipate that it will be found recent on our own coasts.
(229.)

Having now briefly described the new forms in the Glen-
shira sand, so far as they are here figured, I am compelled to
postpone the remainder to the next number of the Journal,
in which another plate will be required for them, as very
nearly as many remain to be described as we have now been
enabled to figure. In the meantime, besides the Eunotia
Falx, which is not yet a British form, we have described 18
new forms, all from this one deposit, and one new to Britain.
These, added to the list of known forms, make up the
number of 229 species now recorded as occurring in the
Glenshira sand, besides those to be hereafter noticed and
figured.

It may be noticed here, that I intend to publish, as soon as
the necessary figures can be prepared, a description of a very
remarkable series of forms, occurring both in the Glenshira
sand, and in various fresh-water gatherings, in which, indeed, I
first observed them. They agree perfectly in general aspect,
and the peculiar characters of the markings; but differ to a
very surprising degree in form or outline. These may possibly
constitute several species, and would certainly be considered
as such by some authorities. But, both on account of their
resemblance, or rather identity, in markings, and from the
occurrence of intermediate or transition forms, by which the
different types appear, in many cases at lenst, to pass into
one another, there is some ground for regarding them as be-
longing to one species, Without deciding this question, T

CONTAINING DIATOMACEOUS EXUVIE. 43

have, for the convenience of description, grouped them under
the name of Navicula varians, and I feel assured that the study
of these forms will throw much light on the question, to which
I have already directed attention, of the true value of form as
a specific character.

I cannot cenclude, for the present, without expressing the
very great obligations | am under to Mr. Tuffen West, not
only for the great care and accuracy with which he has drawn
and engraved the figures, but also fer the valuable assistance
I have derived from his extensive and exact knowledge of
the British Diatomacee in this long and laborious investiga-
tion. It is, indeed, fortunate for British microscopists that
they have an artist who is not more distinguished for the
beauty of his drawings than for his knowledge of the micro-
scope, and his intimate acquaintance with the objects to be
represented.

N.B.—Since the preceding pages were printed, I have
observed a fragment of Synedra undulans in a slide from
Poole Bay, sent to me by the Rev. W. Smith. I have no
doubt that the gathering, if searched, will yield entire speci-
mens) I am-also informed by M. de Brébesson that he has
seen the same form in marine gatherings from Brest, but
supposed it to be S. gigantea, Lobarzewsky, from which species,
however, he now finds it to be quite distinct.

I may take this opportunity of mentioning that the follow-
ing species must be added to the list of known forms in the
leshim sand, as I have noticed them quite recently.

230. Trybleonella angusta. 233. Gomphonema cristatum.
2a 5 Scutellum. 234. Mastogloia apiculata. Sm.
232. Amphiprora elegans, Bleakley.

No. 232 is a splendid marine form, observed last spring
by Mr. Bleakley, near Harwich. No. 234 is a very fine
marine species, which occurs in great abundance along with
232 at Poole Bay. I have understood that Mr. Smith has
named it as above, but that it may possibly be referable to
another ea G.

A few Remarks on a Paper, read before the Royal Society by
Dr. J. W. Grirritu, on the ANGULAR APERTURE of Opsect-
Grasses. By Dr. F. Dp’ ALQUEN.

In the last number of the ‘ Microscopical Journal’ an abstract
of the above paper was given, and, if you think the subject of
sufficient interest to your readers, I should feel obliged if the
following observations could appear in your next number, in
refutation of the only novel point in Dr. Griffith’s paper.

44 DR. F. DDALQUEN ON

Mr. Wenham states, in one of his valuable papers, that the
markings on test objects become visible by a contrast of light ;
and the attention of the reader will at once be brought to the
point upon which the whole question hinges, when I add that
the gist of Dr. Griffith’s paper is an attempt to show how this
contrast of light is produced, and why the markings can only
be seen under an object-glass of large angular aperture, and
not with one which is deficient in this respect, however great
its magnifying power may be. In answering these proposi-
tions the Doctor states, in substance :—The markings, those
ona valve of a Gyrosigma, for instance, being in reality de-
pressions, the light, on passing through them, suffers greater
refraction from the perpendicular than the set of rays corre-
sponding to the undepressed, thicker, and therefore more
highly refractive portion of the valve, and we have thus two
sets of rays of different degrees of obliquity—the former of
which, as the most oblique, is tilted out of the field of the
microscope, whilst the second set is admitted, if the angular
aperture of the object-glass is sufficiently large; and thus is
the contrast of light produced which renders the markings
visible. If the aperture of the object-glass is deficient, no
contrast is produced, and the markings remain invisible ; but
the explanation of this point is the author’s difficulty, and it
is not easy to single out in precise language his meaning, At
all events, the “‘ rem invisam verba sequuntur”” we cannot apply
to this part of his explanation, which, in so acute an observer
as Dr. Griffith generally is, can only be accounted for by his
labouring under the difficulty of having te reconcile facts to a
preconceived speculative theory of his own.

It is self-evident, if the tilting out of one set of rays were the
cause of the markings becoming visible, that this must equally,
and even more readily, take place under an object-glass of
small aperture, because not only the rays tilted out from the
object-glass with large aperture, but even those admitted by
it, as far as they exceed the angular aperture of an object-
glass with deficient aperture, are naturally excluded, or tilted
out with regard to the latter; in fact, no rays could by any
possibility become excluded from an object-glass, with large
aperture, which were not ¢o zpso also tilted out from an object-
glass with deficient aperture: it is therefore clear, as expe-
rience tells us, that certain markings cannot be seen with such
a glass under any circumstances, that the contrast of light is
not produced in the manner stated, nor can the tilting out of
certain rays, if it takes place at all, be the cause of rendering
the markings visible. ‘This objection loses, also, nothing of its
force when the author states, that the angular aperture must

THE ANGULAR APERTURE OF OBJECT-GLASSES. 45

be greater as the markings are more delicate, because it would
require greater obliquity of the light to exclude one set, and
the other would be too oblique to enter the object-glass, unless
it be of corresponding large aperture. | Now I do not see the
cogency of this, because, in this sentence, if he had said, that
the obliquity of light required must be greater if the aperture
was large, I readily could understand him, though the inverse
would be equally clear, viz., that the obliquity of the light
required for the excluewn of one set of rays would be lea if
the aperture were small; but why the obliquity must be
greater as the markings are more delicate I cannot understand,
nor has the author given us any reason for it, but assumes it
as a natural consequence, as implied by the word ‘ because.”

If there was a law in optics, that, by greater obliquity of
light, the ratio of con- or di-veraener between two rays was in-
creased, I readily could admit the pertinence of the above
foetal ; but that would be saying that the refractive index of
any medium varied with the angle of incidence, while we
know that the sinuses of the angles of incidence and refraction
stand, with regard to the same medium, always in a constant
proportion. The greatest obliquity of light is therefore sepa-
rate, the two sets of rays not more than they are under. ordi-
nary illumination. Further, if the second set is likewise too
oblique to enter the object-glass, if not of corresponding large
aperture, it would follow, that, under an object-glass of defi-
cient aperture, both sets of rays, those corresponding to the
depressed (the first), as well as those corresponding to the
undepressed portion of the valve (the second set), are excluded,
and thus nothing at all of the object could be seen, which is
simply absurd. In disregard of the simple and plain fact that
the efficacy of the greater over the lesser aperture depends
upon the admission and not upon the exclusion of certain rays,
the author goes on to say: ‘ The most difficult point has been
to explain how it is that an object-glass of large aperture will
render markings evident which were not visible under an
object-glass of smaller aperture.” I freely admit that, as I
have shown, if we adopt the author's theory, the explanation
is not only difficult but impossible. Nor does this difficulty
vanish, as he states it does, when we recollect that the addi-
tional rays admitted by the larger aperture are more oblique ;
because, how can the admission of additional rays prove the
tilting out of others, which is the point at issue? Observe:
hence one set of rays will be refracted from the field (pray,
why ?), whilst the other will enter. In my opinion, there is
no sequitur, which that very convenient little word ‘hence ”
seems to imply, but the same gratuitous assumption as we have

46 DR. F. D’ALQUEN ON ~

already noticed before. Moreover, it must not have appeared
quite conclusive to the author himself, because he continues :
“Or to simplify this most important point, the object may be
regarded as illuminated by two sets of rays, one correspond-
ing to those admitted by the object-glass of the smaller aper-
ture, the other set, to these plus those admitted by the excess
of angular aperture of the second over the first.” Now we
may not only regard with the author the object as thus illu-
minated, but we know that such is actually the case, and that
the efficacy of the larger aperture over the lesser depends
simply on the admission of additional rays which were too
oblique to enter the latter; but simple as this is, we must ask
again, how can the admission of additional rays, here assumed,
prove the tilting out of others? Mark the answer: the first
set not being sufficiently oblique to allow a portion of them
being refracted beyond the angular aperture of the first object-
glass, while the second set are so. Now every one will admit
that this illustration proves nothing, because the rays admitted
by the first object-glass are as oblique with regard to its
angular aperture, and the practicability of becoming tilted out
as the rays entering the second to its corresponding larger
aperture.

Another objection which is, @ priort, as palpable as those I
have already noticed is this: if the markings are rendered
visible, by the tilting out of certain rays, it would follow,
as the fewer rays will be tilted out the greater the aperture,
that the markings, instead of becoming more distinct, must have
their. distinctness impaired in the same proportion as the
angular aperture is increased ; yet experience tells us that the
reverse is the case. If we further assume that the illumina-
tion remains the same, the more we increase the angular aper-
ture, the more it would become impossible to realize the
alleged conditions for rendering the markings visible; and
with every degree added to the aperture, the markings ought
to get fainter, which is contrary to the fact. Lastly, from the
excessive minuteness of the depressions, it appears to me
highly improbable that the difference thereby occasioned in
the thickness or substance of the valve should be the cause of
giving a different refractive index to different portions of the
valve; and [ feel more inclined, with other observers, to attri-
bute the modification which the light undergoes, on passing
through it, to peculiarities in the structure of the markings
themselves. However, let us proceed from assertions and
counter assertions to practical experiment, the ultima ratio
in an inductive science.

By means of a small pipe of an injecting syringe, with an

THE ANGULAR APERTURE OF OBJECT-GLASSES. 47

opening of 1:30” diameter, fixed to a small glass tube in an
adaptor, in the place ef the achromatic condenser, I illumi-
nated the prepared valve of a Pleurosigma Balticum, mounted
dry, by as direct and straight a light as could be done; and
under an object-glass (+), whose aperture I had reduced to 50°,
both sets of striz were visible. I next increased the aperture,
by substituting a larger stop, to 65°, and the markings became
much more distinct. A similar result was obtained by suc-
cessively increasing the aperture to 75°, and, lastly, to 90°,
when the distinctness of the markings was most strikingly
increased, and the whole object more brightly illuminated.
It cannot be doubted that a similar result would have been
obtained, had I been able still to increase the aperture of the
object-glass ; and if the author’s theory was correct, in doing
so, the light being straight, the markings ought to have be-
come fainter and fainter, and disappeared entirely at last, as,
with every degree added to the aperture, fewer rays could
become refracted out of the field of the microscope.

This experiment proves further, the light being direct and
straight, that the obliquity of the emerging rays must be due
to the peculiar structure of the markings, and does not arise
from a difference of density, as assumed by the author; and
further, that the visibility of the markings depends upon
aperture and not upon illumination, though the latter may
serve to increase their distinctness, while, without the former,
any kind of illumination would remain ineffective.

A similar experiment, previously made, baving made it
probable that the set of rays corresponding to the depressions
did not pass through them at all, but was completely inter-
cepted, and either refracted or reflected into the substance of
the valve towards the margin of the depressions, thus leaving
the latter themselves dark, it was desirable to devise another
experiment, on such a scale as would admit of a practical
proof regarding the phenomena concerned. For this purpose,
I put a thin layer of Canada Balsam, nearly deprived of its
turpentine, so that it hardens as quickly as it cools, on an
ordinary glass slide, and, with the delicate bristles of a seed
of an Erodine, I made a number of minute markings respect-
ing depressions while the balsam was yet soft, but not so soft
as to stick.* It being admitted that the markings on the
gyrosigma, for instance, consist of depressions in the siliceous
substance of the valve, and Canada Balsam having almost
the same refractive index as silica, agreeably to Mr. Wenham’s

* Tf the balsam is already too hard, it cracks, the surface of the depres-
sions, becomes uneven, and forms new sources of refraction, which is also
the case if the markings penetrate down to the glass.

48 ON THE ANGULAR APERTURE OF OBJECT-GLASSES.

experience, I had thus, as nearly as I could, imitated, on a
large scale, the valve of a Gyrosigma. On examination cofetlie
slide thus prepared under the microscope, I found it covered
©} with dark spots or dots, surrounded by a very lumi-
© nous mar gin or ring. bas may even be seen if the
slide is laid on white paper and closely examined ;
each indentation produced in the layer of balsam
will instantaneously be followed by a shadow or dark spot on
the paper, with its halo.

Now, if the markings had, in this instance, been as close
and near to each piheel as is the case in the athe of a Gyro-
sigma, for instance, this experiment would have lost a great
deal of its interest, because, in that case, the luminous rings
would have fee confluent, if I may borrow this expression,
and invisible, by being lost zz, and forming the general illu-
mination of the undotted portion of the layer; but, as seen
now, each opaque spet has it own halo, which is of course
produced by the interception of the rays corresponding to the
depressions, which, instead of passing through them, emerge
at their margins, thus forming a luminous ring, leaving the
depressions themselves dark, Now, be it well observed, this
is the identical set of rays which, according to Dr. Griffith’s
theory, is refracted out of the field altogether ; and it is evi-
dent, if that had been the case in this eects the luminous
rings would not have been formed at all. But in order fur-
ther to prove that no rays are tilted out of the field proceeding
from the depressions, I drew out before the blowpipe a small
glass tube in a very fine hair-like filament, and this delicate
condensor I held directly over the opaque depressions, with-
out, however, receiving any evidence of rays issuing there-
com while the portion above the halo was likewise brilliantly
“itp oatrevar This is, I think, the most direct way of
disproving Dr. Griffith’s hypothesis. If the phenomena
witnessed in this instance are the same as occur in the exa-
mination of the valve of a gyrosigma, the manner in which
the markings are displayed and rendered more or less dis-
tinct, accordingly as the aperture of the object-glass is large
or small, finds an easy and natural explanation in the differ-
ence of the aperture itself, and its ordinary operation. The
luminous rings are formed mainly of oblique rays proceeding
from the lowest point of the depressions upwards and round
them ; the greater the aperture, the more oblique rays enter,
and the greater the contrast, and vice versa. If we depress
the object-glass gradually, we can trace the rays down to the
point from which they proceed—the dark spot gradually dis-
appears, and is at last replaced by a very brilliant point, from

ON THE STRUCTURE OF NOCTILUCA MILIARIS. 49

which the rays seem to radiate in all directions ; if we depress
still further, this lumimous spot also disappears, and we see
nothing but the uniformly-illuminated layer of balsam. If
the aperture of the object-glass is small, the luminous rings
are either not seen at all, or fainter, in proportion to the
extent of the aperture; and, on depressing the object-glass,
the opaque spots disappear at once, and we cannot trace the
rays of the ring down to the lowest point. For the sake of
greater accuracy, I made these observations with the same
object-glass, the aperture of which gradually diminished by
stops. It is also necessary that, during the different trials, we
should always have the same focus; this cannot be done by
looking at the opaque depressions, but by bringing any other
fine mark or scratch on the surface of the layer always first to
its exact focus. Candlelight is preferable to daylight. I did
not use a condensor, but the ordinary plane-reflecting mirror,
being anxious to study the phenomena under their most simple
conditions. At certain inclinations of the mirror, the dots
become much elongated, so that one can easily understand
how rows of dots, if close together, produce the appearance of
lines. I have thus not only proved that the theory advanced
by Dr. Griffith is untenable, and contrary to fact, but also
shown, or made it at least probable, how the contrast of light
is produced which renders the marking visible.

On the Structure of Nocritvca mitiaris. By Tuomas H.
Hux ey, F.RS.

Amone the many striking and beautiful appearances pre-
sented by the Ocean, there is none, perhaps, which has
more attracted the attention both of the naturalist and of the
casual observer, than the silvery, sparkling, phosphorescent
light, which may often be seen on dark nights, illuminating
the track of every boat and defining the contours of the
waves as they break upon the shore.

After long serving as a fertile subject of doubt and dis-
cussion, it is now well known that this luminosity proceeds
from many sources; in the main, from living invertebrate
animals— Protozoa, Polypes, Medusa, Amnelids, Crustaceans,
&c. Among these again, the chief and most important part
is played, as was first shown in the middle of the last century
by M. Rigaut, and again in 1810 by M. Suriray,* by a sin-
gular and anomalous creature of very simple organization, the
Noctiluca miliaris.

* See Quatrefages, l.c. I regret that I have not access at this moment
to M. Suriray’s paper.

VOL. III. E

50 ON THE STRUCTURE OF NOCTILUCA MILIARIS.

According to M. Suriray the Noctiluca is a spherical gela-
tinous mass, provided with a long filiform tentacle or ap-
pendage, presenting a mouth, an cesophagus, one or many
stomachs and ramified ovaries, and thus possessing a certain
complexity of organization. Te Blainville confirmed Suri-
ray’s account, sib placed Noctiluca, without doubt most erro-
neously, among the Diphydz, On the other hand, Van Beneden
Verhaeghe and Doyére, denying the relation of Noctiluca
with the Acalephz—and_ conceiving its organization to be
of a much more elementary character
Rhizopoda,

To this doctrine M. de Quatrefages also attaches the
weight of his authority in his valuable essay ‘ Observations sur
les Noctiluques, published in the Annales des Sciences Nat.
for 1850. M. de Quatrefages does not admit the existence
of any true mouth or intestinal canal, and considers that the
so-called stomachs are nothing but ‘vacuoles’ similar to these
observed in the Rhizopoda and Infusoria.

In a short memoir published in Wiegmann’s Archiv. for
1852, however, that excellent and most accurate observer,
M. Krohn, carried the subject a stage further, and showed
that the organization of Noctiluca is more complex than_has
been supposed. Krohn carefully describes and figures the
mouth of WNoctiluca and the long vibratile ciliwm, which he
was the first to observe, proceeding from it. Krohn draws
particular attention to the oval body first described by
Verhaeghe, which he considers to be the homologue of
the ‘nucleus’ of the infusoria; and describes the ejection
of fecal matters. Arranging the NVoctiluca among the
Protozoa, Krohn points out some interesting structural
analogies with Actinophrys and Paramecium.

I will now proceed to detail the results of my own ob-
servations.

Noctiluca miliaris (Plate V. figs. 1, 2) may be best de-
scribed as a gelatinous transparent body, about 1-60th* of an
inch in diameter, and having very nearly the form of a peach ;
that is to say, one surface is a little excavated and a groove
or depression runs from one side of the excavation half way to
the other pole (échancrure, Quatrefages. Frauenbnseniihnliche
Einbucht, Krohn). Where the stalk of the peach might be,
a filiform tentacle, equal in length to about the diameter of
the body, depends from it, and exhibits slow wavy motions
when the creature is in full activity. I have even seen a

* The extremes of size are given by Krohn as 1-7 —1 millimetre
= 1-170 — 1-25 inch about.

ON THE STRUCTURE OF NOCTILUCA MILIARIS. 51

Noctiluca appear to push repeatedly against obstacles, with
this tentacle.

The body is composed of a structureless and somewhat
dense external membrane, which is continued on to the
tentacle. Beneath this is a layer of granules or rather a
gelatinous membrane, through whose substance minute gra-
nules are scattered without any very definite arrangement.
From hence arises a network of very delicate fibrils, whose
meshes are not more than 1-300(0th of an inch in diameter
(fig. 6), and these gradually pass internally,—the reticulation
becoming more and more open—into coarser fibres, which
take a convergent direction towards the stomach and nucleus.
All these fibres and fibrils are covered with minute granules,
which are usually larger towards the centre.

Quatrefages states that these granules may be seen to glide
from the centre to the circumference, and vice versd, propelled
by the contractions or expansions of the transparent matrix
in which they are imbedded; that new fibrous processes
(expansions) arise on the central mass and unite, dividing and
subdividing, with the neighbouring ones—and that if the
creature be irritated, the fibres and fibrils become detached
from the investing membrane, and are drawn in towards the
mouth “like threads of a very viscid liquid, which retract
slowly after being broken.”

All these appearances may be very readily seen; but I am
strongly inclined to believe that the greater part of them are
abnormal states, and that in their natural and perfectly un-
altered condition, the fibres and fibrils are perfectly quiescent,
and present nothing to be compared with the protean move-
ments of the Amebe. In their perfectly fresh and unchanged
state, in fact, the fibrous network is by no means so obvious
as it usually appears, and in such specimens [| have been
unable to convince myself that the granules undergo any
change of place—certainly there is no protrusion and retrac-
tion of processes to be compared with that which takes place
in the Rhizopoda.*

The oral aperture has been satisfactorily described by
Krohn. Supposing the animal to lie upon its oral face (the
attitude it commonly assumes), with its tentacle forwards—
the oral aperture appears as a sort of half oval, with a nearly
straight edge anteriorly, and a deeply-curved outline pos-

teriorly (fig. 4).

* Krohn states, that he could hardly ever cause the Noctiluccee to con-
tract by mechanical or chemical irritation; but that he once saw one
which repeatedly contracted before falling into the permanently wrinkled
and collapsed condition, into which they so readily pass.

E 2

52 ON THE STRUCTURE OF NOCTILUCA MILIARIS

The anterior edge is not quite straight, but is formed by
two ridges, apparently of a harder substance than the
remainder of the outer membrane, which run up on the two
sides of the fissure, and unite, forming a very obtuse angle,
open anteriorly, in the base of the tentacle:

The latter is a subcylindrical filament of 1-1800th inch
diameter, more or less flattened, sometimes quite flat at its
free end, which is rounded at the apex. It is a little broader
at its base than elsewhere, and consists of an external struc-
tureless membrane continuous with the general investment,
and of an internal substance, which is so marked by transverse
granular lines, as very closely to resemble a_ primitive
fibril of striped muscle. I agree with Krobn that the
striation is not in the external membrane, as Quatrefages
states.

From the bottom of the oral cavity a very delicate filament
(fig. 3), which exhibits a rapid undulating motion, is occa-
sionally protruded, and then suddenly withdrawn. Krohn,
who first discovered this singular organ, considers that it plays
an important part in sweeping nutritive matters into the oral
cavity, and there can be little doubt that such is the case. I
would warn future observers not to be easily discouraged in
their search for this organ. I had sought for it in at least
fifty individuals without success; and nothing but the firm
confidence in M. Krohn’s accuracy, with which frequent
working over his ground has inspired me, led me to per-
severe antil I had discovered it. Among the great numbers
of Noctiluce which I examined, Peeeee I aa not observe
half a dozen which presented a good view of the czliwm.

Under these circumstances, I do not comprehend how it is
that M. Krohn should have overlooked a very remarkable
structure which requires no such sharpness of vision as that
to which I have just alluded. I refer to an S-shaped ridge
arising close to the right extremity of the anterior oral margin
above described, and passing down on the right side of the
oral aperture to form its lateral and posterior boundary.

This ridge is horny-looking, and is considerably produced
in its middle portion into a tricuspid prominence (fig. 4 d@),
for which | know of no better name thana ‘tooth.’ This tooth
is about 1-700Uth in. high ; its middle cusp is stronger than
the other two, and bifid, while the posterior has a slight
pointed heel. I have never observed any movement in this
tooth-like body.

Behind it the oral aperture narrows to inclose what may be
termed a post-oral space, and then widens again; the eleva-
tions bordering this post-oral space are continuous with those

ON THE STRUCTURE OF NOCTILUCA MILIARIS. 53

which form the sides of the triangular groove or fissure, which
has been above described as running up on one side of the
body (figs. 1,2). In the midst of this flattened post-oral space
there is a small funnel-shaped depression, which I am strongly
inclined to believe is an anal aperture (fig. 3 //f).

The oral aperture leads into the granular mass of the ali-
mentary cavity, from which the fibres and fibrils radiate.
Quatrefages says :—

** At one part of the groove of which we have spoken, and near the
point of insertion of the appendage, there is always a little mass of
different substances, sand, &c., which can only be detached with great
difficulty. When this has been done these foreign bodies are seen to have
simply adhered to a semi-transparent, granular substance, which projects
like a hernia, so to say, from a little orifice (mouth of authors) by which
the membranes are perforated. This external substance is continuous
with a much larger internal mass of the same nature, whose dimensions
and form vary in each individual.

** However carefully I have sought for a digestive canal of any kind, I
have never been able to discover anything of the sort; but I have very
frequently seen more or less considerable vacuoles in the midst of this
substance. It is these most probably which have been regarded as
stomachs by MM. de Blainville and Suriray.”

I have never seen this projecting mass nor any foreign
bodies in the position indicated by Quatrefages, in perfectly
fresh specimens. In those which had undergone alteration,
on the other hand, such an appearance was frequent, but it
invariably appeared to me to result from a partial extrusion
of the contents of the stomach.

The appearance of ‘ vacuoles,’ on the other hand, is almost
invariable in fresh specimens; but I cannot think that these
clear spaces, which are defined by a well-marked membra-
nous wall, have any analogy with the shifting ‘ vacuoles’ of
the Infusoria and Rhizopods. It appeared to me, on the other
hand, that the oral cavity led directly in a definite stomach,
whose walls are capable of very great local dilatation, such
dilatations, connected by very narrow pedicles with the central
cavity, then having all the appearance of independent vacuoles
(fig. 3.¢e). The accumulation of granules around the central
mass greatly contributes to this appearance. Like Krohn,
I frequently noticed large Diatomacee and other foreign
matters in these gastric pouches.

Not only does all I have observed lead me to believe that
Noctiluca has a definite alimentary cavity, but I am, as I
have said above, inclined to think that this cavity has an
excretory aperture distinct from the mouth. The funnel-shaped
depression in the post-oral area, in fact, always appeared,
when I could obtain a favourable view, to be connected with
a special process of the stomach. On one occasion I observed

54 ON THE STRUCTURE OF NOCTILUCA MILIARIS.

the sides of this process to be surrounded by fusiform trans-
versely-striated fibres or folds, I could not determine which.

Krohn states that he repeatedly saw the eyesta voided ‘ in
the neighbourhood of the groove of the body,’ but he could
not determine at what exact point, and he inclines to think it
must have taken place through the mouth.

I am equally unable to bring forward direct evidence on
this point, and my belief in the existence of a distinct anus is
founded simply on the structural appearances.

In front of and above the gastric cavity is the nucleus (c),
described by Verhaeghe and Krohn. This is a strongly re-
fracting, oval body of about 1-460th inch in length, which,
by the action of acetic acid, assumes the appearance of a
hollow vesicle. The anterior radiating fibres pass from it ;
the posterior from the alimentary canal.

Quatrefages and Krohn consider that a process of fissiparous
multiplication takes place in Noctiluca; both of these ob-
servers having found double individuals, though very rarely.
According to the latter writer, division of the body is pre-
ceded by that of the nucleus, 1 have not had the good fortune
to meet with any of these forms, and the only indication of a
possible reproductive apparatus which I have seen consisted
of a number of granular, vesicular bodies (fig. 5 h), of about
1-2000th inch in diameter, scattered over the surface of the
anterior and inferior part of the body.

Such is what repeated examination leads me to believe is
the structure of Noctiluea; but if the preceding account be
correct it is obvious that the animal is no Rhizopod, but must
be promoted from the lowest ranks of the Protozoa to the
highest.

The existence of a dental armature and of a distinct anal
aperture, are structural peculiarities which greatly increase
the affinity to such forms as Colpoda and Paramecium, indi-
cated by Krohn. Nocti/uca might be regarded as a gigantic
Infusorium with the grooved body of Colpoda, the long pro-
cess of Trachelius, and the dental armature of Nassu/a united
in one animal.

On the other hand, the general absence of cilia over the
body, and the wide differences in detail, would require the con-
stitution of at least a distinct family for this singular creature.

Economy of Crostertum Lunura. By the Hon. and Rev.
S. G. Osporne, Communicated by Jasez Hoae, Esq.

Tue division of labour-principle holds as° good amongst
microscopists as amongst any other workers in the fields of

ON THE ECONOMY OF CLOSTERIUM LUNULA. 55

knowledge. | have devoted now for some months, and on an
average several hours almost daily, to the study of some of the
Desmidiee, especially the Closterium Lunula. With increased
objective powers and the use of improved methods of illumi-
nation, | have arrived at results which may, I think, interest
many of your readers.

As to the Clostertum Lunula, | have ascertained that the
best view of its circulation and the cilia which gives it its
unpulse, is obtained by the use of full sunlight transmitted
through the combination of coloured glass, proposed by
Mr. Rainey, and adapted to an achromatic condenser. I have
used a 1-6th objective of Ross’s, his 1-4th with the Rainey
moderator as illuminator, In diagram A, I have given a
rough sketch of a specimen of the C. Lunula; with the
above arrangement of the microscope, using also a deep eye-
piece, I have again and again seen the cilia in full action along
the edge of the membrane which encloses the endochrome ;
I have seen them also, but not so distinctly, along the inside
of the edges of the frond itself. Their action is precisely, to
my eye, the same as that in the branchiz of the mussel.
There is the same wavy motion, and as the water dries up
between the glasses in which the specimen is enclosed, the
circulation gets fainter at the edges, and the cilia are seen
with more distinctness.

In the diagram, I have drawn a line at 6 to a small oval
mark; these exist at intervals, and more or less in number
over the surface of the endochrome itself, beneath the mem-
brane which invests it. They seem to be attached by a small
pedicle, are usually seen in motion on the spot to which they
are thus fastened ; from time to time they break away, and are
carried by the circulation of the fluid, which works all over
the endochrome, to the chambers at the extremities, there
they join the crowd of similar bodies, each in action within
those chambers, when the specimen is a healthy one.

The circulation, when made out over the centre of the
frond, for instance at a, is in appearance of a wholly different
nature from that seen at the edges. In the latter, the matter
circulated is in globules, passing each other, in distinct lines,
in opposite directions; in the circulation as seen at a, the
streams are broad, tortuous, of far greater body, and passing
with much less rapidity. To see the centre circulation, I
have used a Gillett illuminator and the 1-6th power, so working
the fine adjustment as to bring the centre of the frond into
focus; then almost losing it by raising the objective; after
this, with great care working the milled head till I just

56 ON THE ECONOMY OF CLOSTERIUM LUNULA.

make out the dark body of the endochrome; a hair’s-breadth
more adjustment gives me this circulation with the utmost
distinctness if it is a good specimen, It will be clearly seen,
by the same means, at all the points where I have put spaces,
and from them, may be traced, with care, down to both
extremities.

The endochrome itself is evidently so constructed as to
admit of contraction and expansion in every direction; at
times the edges are in semi-lunar curves, leaving interrupted
clear spaces visible between the green matter and the investing
membrane; at other times, I have seen the endochrome with
a straight margin, but so contracted as to leave a well-defined
transparent space, along its whole edge, between itself and
the exterior of its sac. It is interesting, in this case, to
keep changing the focus, that at one moment we may see the
globular circulation between the outer and inner case, and
again the mere sluggish movement between the inner case and
the endochrome.

I have now not the slightest doubt but that the loose bodies
in the chambers at each extremity of the frond are brought,
as I have described above, from the exterior of the endo-
chrome, by the external current; what they are I do not
profess to say; they are as the rule diamond-shaped, when
at rest.

In B, I have given an enlarged sketch of one extremity of
a C. Lunula. The arrows within the chamber pointing to d,
denote the direction of a very strong current of fluid T can
detect, and occasionally trace most distinctly; it is acted
upon by cilia at the edges of the chamber, but its chief force
appears to me to come from some impulse given from the
very centre of the endochrome. I have seen the fluid here
acting in positive jets, that is with an almost arterial
action ; this it is, which, according to the strength with which
it is acting at the time, propels the loose floating bodies at
a greater or less distance from the end of the endochrome;
the fluid thus impelled from a centre, and kept in activity
by the lateral cil’a, causes strong eddies, which give the
twisting motion we see to the said free bodies. The line
— a, in this diagram, denotes the outline of the membrane
which encloses the endochrome; on both sides of this I can
detect cilia. ‘The circulation exterior to it passes and repasses
it in opposite directions, in three or four distinct courses of
globules; these, when they arrive at — c, seem to encounter
the fluid jetted through an aperture at the apex of the
chamber; this disperses them so that they appear to be

ON THE ECONOMY OF CLOSTERIUM LUNULA. 57

driven, for the most part, back again on the precise course
by which they had arrived; some, however, do enter the
chamber: occasionally, but very rarely, I have seen one of the
loose bodies escape from within, and get into this outer
current, in which it is carried about, until it becomes adherent
to the side of the frond. I am now quite satisfied that in the
case of the specimen diagram C (p. 235, Vol. II.), to which I
referred in your last number, the pressure of the glass in which
the specimen was enclosed fad forced the endochrome so far
up into the chamber, that the jetting action of the fluid, nomi-
nally acting within the frond, was thus made to play exterior
to it.

With regard to the propagation of the C. Lunula, 1 have
never seen anything like conjugation, but 1 have repeatedly
seen what I shall now describe—increase by sel{-division.

Let me request your readers to observe the diagram D,
but for the moment to suppose the two halves of the frond,
represented as separate, to just overlap each other; I have
watched for hours the process of complete division ; one-half
has remained passive, the other has bad a motion from side
to side, as if moving on an axis at the point of juncture; the
separation has become more and more ardent, the motion
more active, until at last with a jerk one segment leaves the
other, and they are then under view as I have drawn them.
It will be seen, that in each segment the endochrome has
already a waist ; but there is only one chamber, which is the
one belonging to one of the extremities of the orate entire
frond. The ‘globular circulation for some hours previous to
subdivision, and for some few hours afterwards, runs quite
round the obtiise end of the endochrome — a, by almost
imperceptible degrees; from the end of the endochrome,
symptoms of an elongation of the membranous sac appear,
giving a semilunar sort of chamber; this, as the endochrome
elongates, becomes more defined, till it has the form and
defined outline of the chamber at the perfect extremity.
The obtuse end — 4 of the frond is at the same time elon-
gating and contracting; these processes go on; in about five
hours from the division of the one segment from the other,
the appearance of each half is that of anearly perfect specimen,
the chamber at the new end is complete, the globular circula-
tion exterior to it becomes affected by the circulation from within
the said chamber ; and, in a few hours more, some of the free
bodies descend, become exposed to, and tossed about in the
eddies of the chamber, and the frond, under a 1-6th power,
shows itself in all its full beautiful construction. E is a

a8 ON THE ECONOMY OF CLOSTERIUM LUNULA.

diagram of one end of a C. didymotocum, in which I saw the
same process.

I have now given you, in as plain a manner as | can, the
result of my further observations ; I invite other lovers of the
science to test their truth; I shall be most glad of any
corrections their greater experience and better skill may
afford ; at any reasonable notice I will send to any of your
readers, a stock of specimens. The best I obtain are from
Branksea Island—Poole Harbour: the best specimens to
examine are those with the lightest green endochrome, and
in which the furrows are most marked. I am so engaged
I will not at this time put forth my theories in connection
with this Desmzdium, for I could only do so in a hasty
and crude manner. I can with truth say, that I am more
than ever convinced that the microscope has not yet shown
me any object so beautiful, so wonderful, and which has so
amply repaid all the trouble I have bestowed upon it.

I would only now add an invitation to brethren of the lens
to try their skill, and the power of their instruments on
Euastrum Didelta ; they will, if I am not mistaken, find in it
wonders, which, when developed, may rival my pet C. Lunula.

coed

TRANSLATIONS, &c.

On the Male reproductive Organs of CAMPANULARIA GENICULATA
(Laomedea geniculata, Lam). By Dr. Max S. Scuutrze, of
Greifswald. (From Miiller’s Archiv. fur Anat. und Physiol.
1850. )

Tue propagation of Campanularia geniculata, described by
Lovén in 1837,* differs essentially from the mode of increase
observed by V. Beneden in several species of the same genus.
In the former species ciliated embryos are produced within
axillary capsules, from vesicles presenting all the parts of an
ovum, and after a distinct process of segmentation. These
embryos, after they have quitted the tunic by which they are
surrounded, and which resembles an incompletely developed
polype, swim about free for some time, and precisely resemble
the embryos of Medusa aurita; they then affix themselves,
and grow into a polype resembling the parent animal. In
the Campanularice, however, described by Van Beneden, me-
dusoid creatures with fentaeles: digestive and sensitive organs,
are produced, also in axillary capsules; and which after
quitting the capsule swim about free in the water and behave
exactly like Medusa. These were regarded by Van Beneden
as the embryos. He considers that they are produced from
ova, and supposes that they subsequently affix themselves, and
after the obliteration and metamorphosis of some of their
organs become Campanularia. Other observers on the con-
trary, particularly Nordmann and Dujardin, regard these
medusiform products of the Campanularie as the developed
forms of those polypes, believing that in the Meduse@ arising
in the asexual way, sexual organs are afterwards developed.
The Campanularié consequently would have to be regarded
as corresponding to the Strobila form of Medusa aurita.
Although the decisive proof of Van Beneden’s view is still
wanting, inasmuch as he has not demonstrated the egg-nature
of the germ of the medusiform animalcules, as well as the
impregnation by semen necessary, in this case, for their
development, and as he, as well as Lovén, did not discover
male seminiferous organs in his Campanularie, still it cannot
* An observation of Kolliker’s should here be noticed. He saw in
Pennaria Cavolinit capsules with spermatozoids (formation of spermatic
filaments in vesicles). It is unfortunate that these capsules and their con-

tents should not have been more minutely described ; nor has the im-
portance of the observation been generally recognized.

60 ON THE MALE REPRODUCTIVE

be denied that a correspondence in the mode of propagation
of the Campanularie, described by Lovén and Van Beneden,
is more readily perceived in an explanation of it according to
the views of the latter, than when it is explained according to
those of Dujardin. I have not, unfortunately, had an oppor-
tunity of observing Campanularie with medusiform offspring,
and consequently must at present refrain from expressing any
judgment in favour of one view or the other. But it appears
to me that everything depends upon the determination of the
fact, whether the medusiform animals are also produced by
sexual propagation like the ciliated embryos of C. geniculata.
If true egg-germs, with the usual transitionary forms into’
embryos, are found in the axillary capsules of Van Beneden’s
Campanularia (as stated by that author), and in other capsules,
spermatozoids, in the way I am about to describe as obtain-
ing in Campanularia geniculata, no farther doubt, perhaps,
could be entertained with respect to the embryonic nature of
the medusiform offspring ; and their development into sexual,
self-propagative Meduse would, according to all known
analogies, have to be regarded as impossible ; but if, on the
contrary, it is found that the Medus@ arise in an asexual way
in the capsules, and that analogous spermatic capsules do not
occur at all, we should in that case expect to witness the
development of sexual parts only in the Meduse, and con-
sequently should have to regard the Campanularie merely as
developmental forms of Acalephe. In Campanularia geniculata,
then, the polypoid envelopes of the ova and embryos, as well
as the spermatic globules presently to be more particularly
described, should necessarily be regarded as analogous to the
Meduse, although they never become free, nor exhibit any
kind of movement whatever beyond a slight motion of the
tentacles, and are wholly incapable of receiving nutriment.

In the genus Campanularia, therefore, we have true polypes,
whose representatives are Campanularia geniculata and others,
which might be regarded only as developmental conditions of
an Acalepha, exactly as is the case with the species of Coryne,
many of which, as tor instance C. squamata, develop ova and
spermatic capsules, which never separate from the polypes,
but after being emptied of their contents become detached ;
whilst in others, as in Coryne aculeata, these capsules are
detached before the complete development of the ova or of
the semen, and swim about under the form of Meduse, in
which the sexual organs are not developed till afterwards.

Let us now return to our observations. The male organs of
the Campanularieg, containing the spermatic fluid, have not

ORGANS OF CAMPANULARIA GENICULATA. 61

hitherto been recognized. Neither Lovén nor Van Beneden
in their numerous researches on the Campanularie have seen
them, any more than the older observers. But in Steenstrup’s
‘ Researches on the Hermaphroditismus,’* I find a short
notice with respect to them. He says, “‘ In the genera Tubu-
larie, Eudendrium, and Campanularie, I have always found
the ‘nurse’-polypes to present only one sex ; and in Campanu-
laria geniculata, semen was never formed except in precisely
those individuals which were developed under the same con-
ditions as the true females which furnish the ova.”

Krohnf and Kollikert have given some notices with respect
to male organs in other Sertularina. The former observed
spermatic capsules, corresponding to the ovicells in position
and figure, although growing upon separate stems, in Pennaria
Cavolini, EHudendrium racemosum, and Plumularia cristata ;
and the latter also in Sertularia abietina. Precise descriptions
and figures of these organs, however, are wanting ; and with
regard to the development of the spermatozoids, Kolliker
merely mentions that they appear to be produced from elon-
gating vesicles, and figures them accordingly as they exist in
Sertularia abietina.

As IT have had abundant opportunity of observing Campanu-
laria geniculata, I directed my attention at once to the re-
productive organs and the propagative function, and was
fortunate enough, in the autumn of 1849, to detect the male
reproductive organs so long sought for in vain; and the accu-
rate description and representation of which I consider to be the
more justified, since the development of the spermatozoids
also affords wholly peculiar and hitherto unknown relations.

The microscopic examination of the axillary capsules, almost
always found upon the polypidoms of Campanularie, besides
the ovi-capsules so well figured by Lovén, will occasionally
disclose the existence of capsules, containing, not ova but dis-
tinct round globular bodies, of about the same size as the ova,
though filled with a homogeneous granular substance, which
when more minutely examined, after the rupture of the cap-
sules, proves to be constituted of spermatozoids in very various
stages of development.

These male capsules, as | shall term them in contradistinction
to the female capsules containing ova, are indistinguishable
from the latter by the naked eye either in size, form, or posi-
tion. Like those they always spring from the angle, where a
polype branches off from the main stem. Their length when

* German translation by Hornschuch, pp. 66, 67.
+ Miiller’s Archiv., 1843, p. 174.
t Neuen Schweizerischen Denkschriften. Band viii.

62 ON THE MALE REPRODUCTIVE

full-grown is from one-third to one-half a line, their shape is
that of an elongated vase with somewhat sinuous walls, the
sinuosities corresponding to the globules contained in the
interior.

Their peduncle commences with the same peculiar annular
formation as is found in all Campanularie at the origin of
each bud.

The separate spherical bodies by which this capsule is
filled, to the naked eye appear of a whitish-yellow colour ;
they are larger and more opaque towards the wider, upper
end of the capsule, and smaller and more transparent towards
the peduncle. Each of them is surrounded by a thin mem-
brane, and the whole together by a common transparent
envelope. Into each globular mass is continued a process of
the common nutritive substance entering the capsule (intes-
tinal tube of Lovén), which is continued uninterruptedly
throughout the whole polypidom ; this process extends beyond
the semidiameter of the globular body, and there terminates
ina cecal extremity. This nutritive substance of the con-
tents of the capsule, having thus furnished a supply to each
globule, expands beneath the horny cover of the capsule over
its entire extremity, exactly as it is figured by Lovén in the
female capsules. Within this nutritive substance may be
perceived a lively motion of granules probably produced by
vibratile cilia.

If one of these capsules, containing six or seven globules,
be ruptured by compression under the covering glass, whilst
in the microscope, the globules are seen to escape sometimes
at the upper end, after rupture of the lid sometimes at the
lower, if the capsule has been previously cut off from its
peduncle, at the same time being emptied of their contents,
so that it is easy now to recognize all the parts of them.

The uppermost globules contain fully-formed spermatozoids
usually in active motion, with a minute round head scarcely
0:0001'” in size, and a long, excessively delicate, appendage,
distinctly perceptible only under very strong illumination,
which vibrates actively backwards and forwards.

The motion of the spermatozoids cannot be perceived in
the unopened globule, on account of the vast multitude
assembled together—it is apparent only after the contents
have been diluted with water.

The globules situated lower down in the capsule contain
no perfectly-developed spermatozoids, but present them in
various stages of development in the following order, pro-
ceeding from below to above.

The lowermost, smallest globules contain densely-crowded,

ORGANS OF CAMPANULARIA GENICULATA. 63

pale, nucleated, round cells, exactly like the spermatic germ-
cells of other aacealk. In the globules placed higher up
these cells are seen with a paler, alnieet inapparent aaa:
the outline of the cell has lost its uniform rotundity, and
begins to elongate on one side into a short process. As the
development proceeds, the nucleus disappears altogether, the
cell is somewhat smaller and the process longer, and fine as a
hair, exhibiting a very peculiar slow movement, not unlike
that of the motile ciliwm of a Euglena, in consequence of
which the entire cell acquires a quivering motion sometimes
amounting to an inconsiderable change of place. This mo-
tion, however, is quite different hee and slower than that
of a mature spermatozoid, - The cell is thrown from side to
side, frequently appearing as if it was supported upon the
process.

Other forms of development are commonly associated with
the above in the same globule. Every cell has this flexible
process, by the movement of which they are thrown from side
to side; but besides this they have also a greater or less
number of rigid, motionless, less delicate processes, varying in
number from | to 5, and appearing to arise in succession, and
by which these forms are rendered like the stellate cells of
Kolliker, and which are a common stage of development of
the spermatozoids i in the Crustacea. But the latter have no
motile appendage, and are always quite motionless.

I am not aware of any observation of movements at such an
early stage of development of spermatozoids.

With respect to the successive formation of the individual
processes, I have not been able to observe anything certain ;
but it appears to me probable that the motile process after a
time becomes zmmotile, and that a new motile process com-
monly makes its appearance at the opposite point, which
again passes into the motionless state, and so on.

It is only rarely that cells occurred without a motile process.
The greatest number of rigid processes on a single cell, that
fell under my observation, was four.

A necessary precaution to be taken, in order that the motion
of the delicate process should be observed, is the avoiding too
strong and too long-continued pressure upon the capsule with
the view of rupturing it. The best way of proceeding is to
provide that, besides the capsule, there should be a somewhat
more resistant object—a portion of vegetable tissue or of the
polypidom itself—and then, whilst looking through the micro-
scope, to make gradual pressure upon the covering glass until
the capsule is ruptured. If the pressure is now omitted, the
glass usually rises again a little, affording the requisite space
beneath it.

64 ON THE MALE REPRODUCTIVE

In what way the mature spermatozoids are produced from
the above-described motile, stellate cells, | have found it im-
possible to observe. Notwithstanding that I have examined
capsules of all sizes, I have never noticed any transition forms.
The next highest globules always contained spermatozoids,
differing from those in a state of complete maturity only in
their having a somewhat larger body. In their movements
they were precisely alike.

Whether a stellate cell divide into several spermatozoids or
not, must be left undecided. In the Crustacea, we are also
unacquainted with the metamorphoses of the stellate cells, not
knowing even whether in any case they become motile sper-
matozoids. Dromia Rumphii, according to Kélliker, is the
only Crustacean in which, together with stellate cells, bodies
resembling filamentary spermatozoids are also found; but
these were immotile.

The further change which takes place in the spermatic
capsule for the evacuation of its contents is precisely like that
which occurs in the female capsule for the development and
expulsion of the embryos. When the spermatic capsule con-
tains mature spermatozoids in the uppermost globules, the
highest of those bodies breaks through the membrane by
which the capsule is closed, and the envelope of the globule,
which in the mean while had increased somewhat in thick-
ness, represents a rounded sacculus placed upon a peduncle,
and the surface of which opposite to the peduncle is furnished
with a bundle of tentacular appendages. The peduncle en-
closes a continuation of the general nutritive substance, which
at this time projects only for a very short distance into the
spermatozoid-globule. The tentacles exhibit a slight degree
of motility, inasmuch as they are capable of a slow extension
and contraction ; but they have no urticating organs, and are
certainly wholly incompetent for the prehension of nutriment.
Nor at first do they serve for the occlusion of an opening
which is not formed till some time afterwards, when the very
thin membrane in which the spermatozoids are still specially
enclosed is ruptured. No movement of the entire envelope
is ever observable.

Between the inner surface of this envelope and the mass of
spermatozoids there is a space filled with active spermatozoids,
when the membrane by which they are immediately enclosed
is ruptured or bursts spontaneously. But the spermatozoids
do not at once escape externally, as would necessarily be the
case had an opening previously existed at the place where the
tentacles are situated; and it is not until the outer envelope
is also ruptured by stronger pressure that the spermatic ele-
ments are dispersed in the water.

ORGANS OF CAMPANULARIA GENICULATA. 65

When the spermatozoids have been evacuated in the natural
way, the polype-like envelope contracts and ultimately dis-
appears altogether, the next highest of the remaining globules
in the meanwhile escaping in succession. Capsules occur
with four or five polypoid envelopes attached externally, some
of which, however, are always close upon disappearing.

Of the vessels, which Lovén has figured in the precisely
similar egg-tunics seated upon the ovi-capsules, but which I
have never been able to perceive in these tunics, no indica-
tions exist in the spermatic envelopes just described.

The male and female capsules are always placed upon
different polypidoms, so that the semen has frequently a con-
siderable distance to traverse in order to reach the ova to be
impregnated. It may thence be concluded, that in sea-water
the spermatozoids do not speedily lose their motility and
capability of impregnation. TI was still able to perceive the
movements of the spermatezoids an hour after their liberation.

That an impregnation by the semen is indispensably requi-
site for the development of the ova, I have frequently satisfied
myself, since it was only the ovi-capsules which had been
associated with male polypidoms in a glass of water, that
afforded embryos; whilst in those which had been kept apart,
the ova, after entering the polypoid tunics from the ovicell,
were always dissolved. The process of segmentation com-
menced in them, but soon remained stationary, and never
reached the formation of an embryo. This fruitless process
of segmentation taking place without impregnation was also
noticed and figured by Lovén, but erroneously explained. He
regarded it as a spontaneous division of an embryo for the
purpose of multiplication, and believed that each separate cell
would become an embryo.

Lister’s drawing and description (Phil. Trans. 1834, Pl. X.
Fig. b 4, p. 376), cited by Lovén on this point, and regarded
by him as indicating the same thing as this futile division of
the embryo, admit, as it appears to me, of a totally different
explanation. The figure indisputably shows that Lister had
seen the male capsules and the escape of the spermatozoids ;
but he had no notion of the meaning of what he thus ob-
served.

With regard, lastly, to the polypoid envelope of the sper-
matic globules, it corresponds in all respects with the analo-
gous tunic of the ova and embryos.

If the latter is to be regarded as the analogue of the free
medusiform offspring of other Campanulari@ so also is the
former—the tunic of the spermatozoids. I have already said
that the decision of this question cannot be expected without

VOL. III. F

66 ON THE COLORATION OF THE CHINA SEA.

new and precise investigations of the Campanularie having a
medusoid offspring, and therefore shall here avoid all useless
discussion of it.

Memoir on the Cotoration of the Cuina Sea. By M. Camitie
Dareste. (From the Ann. des Sciences Naturelles, IV. Ser.
Tome i. p. 81.)

We learn from the observations of M. Ehrenberg, and more
recently from those of MM. E. Dupont and Montagne, that
the waters of the Red Sea are, at certain epochs, coloured red
by the development, in prodigious quantities, of microscopical
Alege belonging to a species described by the former of these
observers under the name of Trichodesmium erythreum.

These observations, which afford the best explanation of the
term Red Sea, attributed by some ancient geographers to the
aspect of the mountains bordering its shores when illuminated
by the rays of the sun, and by others, since the celebrated Juan
de Castro, to the transparency of its waters, which allows the
coral reefs to be visible in their clear depths, have a still
greater interest for naturalists; they are one of the most re-
markable proofs of the immense development that microsco-
pical organisms can attain, and of their importance in the
physical history of the globe.

There is no such thing as an exceptional fact in science.
The determination of a new fact, however strange it may at
first appear to us, ought always to lead to the knowledge of
other facts of the same nature which can be grouped round
the preceding one, as different effects arising from a single
cause.

Moreover, since these observations have been made, it
has been thought that a great number of the accidental
colorations of sea-water, so often described by navigators,
might be thus explained. It might equally be expected that
similar phenomena would be more frequently observed and
described, from the moment that naturalists showed a scien-
tific interest in them.

I owe to the kindness of M. Mollien, late Consul-general
of France at Havanna, and one of the Frenchmen who have
penetrated furthest into the interior of Africa, the opportunity
of studying a new fact of this kind, which from the conditions
under which it presented itself may one day open up an
interesting geographical question.

M. Mollien observed last year that the China Sea was
coloured yellow and red over a large extent, and that this
coloration was not continuous but in patches separated by

ON THE COLORATION OF THE CHINA SEA. 67

transparent spaces. The red colour predominates in the true
China Sea (Man-Haz), which washes the shores of the south
part of China, to the south of the island of Formosa ; whilst
the yellow colour predominates to the north of the island, and
in the sea specially called the Yellow Sea (Hoang-Hai). The
cause of this phenomenon is unknown. ‘The English who
trade in these latitudes
popular explanation frequently given for all kinds of marine
phenomena, and which had already been applied particularly
to the coloration of the Red Sea.

M. Mollien collected a certain quantity of this coloured
water, and, on his return to France, he kindly intrusted it to
me for microscopical examination. He sent me at the same
time the following note of the conditions under which the
water had been obtained :-—‘‘ The sea-water was drawn up,
the 14th September last, in 10° N. lat. and 106° E. long.
This water was not yellow, as in the canal of Formosa,
but red.”

The quantity of the water I examined was very small; it
had deposited a sort of mud of a brown colour which I placed
under the microscope. I recognised that this deposit was not
formed, as one might at first have supposed, of earthy parti-
cles, but that it consisted entirely of an agglomeration of
minute Algz, almost microscopical and more or less decom-
posed.

These plants presented the appearance of little bundles,
which cannot be better described than as resembling packets
of cigars, and which resulted from the juxtaposition of a cer-
tain number of slender filaments, much longer than broad, of
the same diameter throughout, and terminated by rounded
extremities. These filaments were probably united by a
mucous substance ; but the state of these little plants did not
allow me to ascertain this point. They were divided by a
great number of transverse partitions into a series of cylin-
drical cells, the transverse diameter of which was nearly
twice the longitudinal. ‘These cells were slightly constricted
in the middle, a sort of indication of their ulterior division.
The membrane of the cells was colourless, but the colour
might have disappeared in consequence of the incipient de-
composition which the plants had undergone. In their interior
a certain number of very fine granulations might be observed,
which were slightly tinged with yellow. For the rest, the
little plants were for the most part much changed: a great
number of filaments were scattered in the fluid as well as a
great many isolated cells resulting from the disintegration of
other filaments. The study that I made of these little plants,

EF 2

68 ON THE COLORATION OF THE CHINA SEA.

imperfect as it necessarily was, owing to my having only
fragments more or less altered at my command, has not left
a doubt as to their genuine nature. I found in them directly
all the characters assigned to the genus Trichodesmium by
MM. Ehrenberg and Montagne. The determination of the
species was more difficult. These plants resembled greatly
Trichodesmium erythreum; but I should not have been able
to assure myself on this point, had not M. Montagne, whose
authority on these subjects is so great, and who had kindly
observed my Alga under the microscope, changed my pre-
sumption into certainty.

From this fact, [ could no longer doubt that the remarkable
phenomenon of the microscopical vegetation in the Red Sea
is also presented in the China Sea ; aud that true minute Algz
are the cause of the strange coloration which certain parts of
that sea exhibit.

I wished to know if this fact had been already observed,
and after many fruitless researches, I at last met with a very
curious observation, which made me presume that these little
plants had been already noticed, although the observers had
mistaken their nature, and especially their origin. As this
observation is very interesting in many respects, I shall ven-
ture to give it with some details. It is the chemical and
microscopical examination of some sand which fell. from a
cloud at Shanghai, made by Mr. Piddington, Curator of the
Museum of Economic Geology of India. It is published in
the Journal of the Asiatic Society of Bengal (1846).

This sand had been collected by Mr. Bellott, surgeon to
H. M.S. “ Wolf,” and was transmitted by him to Dr. Mac-
gowan, physician to the hospital at Ningpo, who in his turn’
forwarded it to the Asiatic Society of Bengal.

Mr. Bellott’s letter is as follows :—

“ H, M.S. * Wolf,’ Shanghai, March 16, 1846,
“ My DEar Sir,

“ T sent for the account of a shower of fine sand which fell here
yesterday, the 15th. The wind was N.N.E., No. 1, rather fresh; then
N. E., No. 2; then E.N.E., No. 8; and at last N. E.; and calm at sun-
set. A fog was observed, which was regarded as an ordinary fog; but the
officers who were walking on the shore, remarked that their shoes and
their trousers were covered with dust. I observed it myself in the after-
noon. At 8 o’clock in the evening the dust was visible on the guns, the
upper works, and other polished surfaces on the deck. I gathered as much
of it as I could. In placing the dust upon the finger and raising it in the
direction of the sun’s rays, which on account of this phenomenon had only
half their usual brightness, the particles which composed it were bril-
liant: although impalpable when held between the fingers and thumb,
the dust caused a eritty sensation between the teeth. "The dust passed
over the vessel in light clouds, when the wind freshened; it was some-

ON THE COLORATION OF THE CHINA SEA. 69

thing like the fumes of tobacco, but without any bluish tint. About
2p.M. I walked for two hours in the country: the whole atmosphere
appeared laden with a light cloud of dust, tinged of a brownish colour ;
that was its aspect during the whole day. ‘lhe setting sun had a diameter
apparently less than in the winter evenings, and was of a sickly pale hue.
At 10 o’clock p.m. I spread out two large papers to catch the sand: they
remained spread out until past midnight ; but although the sand fell and
remained upon the guns none fell upon the paper. Was this the result of
an electrical attraction or not? I cannot say. The stars in the Great
Bear, although the firmament was without clouds, were visible only with
difficulty at the zenith. The moon, three days past the full, was partially
obscured, and threw a very feeble shadow upon my hand. At midnight
the moon and the stars resumed their ordinary appearance, and at half-past
one the quarter-master reported that the fog had ceased. The barometer
fell from 380° to 29°88°. The sand set the teeth on edge when one breathed
it. The whole surface of this district is an alluvial clay, without flints or
sand; the nearest sand, which is coarse and shelly, is 12 miles off. It
is said that the merchant ship ‘ Denia’ encountered this shower of sand
at 80°5 miles from the land, in the direction of Leon-Tcheou, and that
there was a kind of pounce-like dust upon the waves. As I have not seen
her log I cannot certify this fact.
“Yours, &c.,
“ J. BELLOTT.”

Dr. Macgowan, in forwarding this letter from Ningpo to
the Secretary of the Asiatic Society, adds the following detail
to the narrative of Mr. Bellott : --

“*T learn from Dr. Robertson, of the steamer ‘ Nemesis,’ of the East
India Company’s service, stationed in this port, that on the day in ques-
tion (15th March), he as well as several other officers had observed similar
phenomena to those described by Dr. Bellott; the vegetation was covered
with sand and also many of the ships, and the atmosphere was clouded.
The wind was N. E. I was then absent at Chusan, where I did not per-
ceive either sand or dust.”

Besides the fact remarked by Mr. Piddington, it appears
from Mr. Bellott’s letter, and also from that of Dr. Macgowan,
that the cloud of dust extended the same day from Ningpo, at
the 30° of N. lat. to Shanghai, at the 314° in round num-
bers, which gives an extent of 90 miles; that it was accom-
panied by light winds from the N. N. E. and from the E. N. E.
during seventeen hours, from 8 o’clock in the morning until
an hour after midnight; that reckoning that the cloud tra-
velled at the rate of 24 miles an hour (and that is the
lowest rate that can be taken), the length of the cloud must
be from 17 x 214, that is to say 42 miles; and thus, in
allowing for the little difference of longitude between Ningpo
and Shanghai, situated very near to one another, one to the
N. W. and the other to the 8. E., there remains an extent of
3,825 square miles for the cloud.

Mr. Piddington reports that having only had a grain and a
half of sand in his possession he could not study it com-

70 ON THE COLORATION OF THE CHINA SEA.

pletely. “It is,” he says,“ an olive-green powder, the grains
of which adhere to one another like the substances which remain
on a filter, and mixed with filaments resembling hairs, of two
kinds, some black, others white and thicker. Under the
microscope, it is evidently a mass of very short filaments or
fibres, transparent, white, black, and brown, with some spi-
cules, reddish, sharp, and with grains of quartzose, transparent
sand, adherent between them.”

With some chemical tests the author recognised in this
dust the existence of an alkaline salt of silex, and he obtained
a small quantity of ammonia by its combustion. He came to
the conclusion that it was formed of animal matter with very
fine fibres, impregnated with an alkaline salt, probably car-
bonate of soda, and containing some grains of quartz. After-
wards observing this sand with a more powerful microscope,
he recognised that these fibres were vegetable structures, and
that they were Conferve.

What could be the origin of this dust? Dr. Macgowan
thought that it might be formed from volcanic ashes, and that
it proceeded from the volcanoes of Japan. But the vegetable
nature of this substance is manifestly opposed to this notion.
Mr. Piddington also to account for the presence of microsco-
pical plants in the sand even offers the following supposition.
This sand and the Conferve which it contains proceed from
the interior of the continent, from the marshes and lakes
which are so numerous in certain parts of China, from whence
they are transported through the air by whirlwinds. It is
true that, during all the duration of the phenomenon, the
wind blew from the north-east. But this difficulty disappears
when the existence of upper currents of the atmosphere is
remembered, which blow in the intertropical regions in an
opposite direction to the trade winds, that is to say, from west
to east, and in the case in question from the land towards the
sea.

I do not know what the physicists will think of this theory ;
but it is evident that the meteorological phenomenon ob-
served by Mr. Bellott can be very easily explained by the
observations which form the subject of the present memoir..
Lf the Conferve, or, to speak more exactly, if the Algze of the
genus T’richodesmium exist in such great abundance in the
China Sea, it can readily be understood how these plants
might be carried by the winds, and sustained in the air for a
certain time under the form of clouds, and how they would
fall during a wind from the north-east, without the existence
of opposite directions of atmospheric currents being necessary ;
it is obvious also that these filaments might be impregnated

ON THE COLORATION OF THE CHINA SEA. y¥-1

with sea-salt, so frequently drawn up, as is well known, by
the evaporation of sea-water, and thus present the reaction of
soda, without it being necessary to seek for the carbonate of
soda in the deserts of Tartary, or the lakes in the interior of
China, as Mr. Piddington suggests. If, further, the extreme
frequency of fogs in the China Sea, and their density, be
remembered, which caused the author of the history of Lord
Macartney’s embassy at the end of the last century to relate
that in the Yellow Sea it was difficult to see from one end of
the ship to the other, it is to be presumed that the phe-
nomenon observed and described by Mr. Bellott is not unfre-
quent, and that there will very probably be opportunities of
studying it anew and in a more complete manner,

It appears to me then, if not entirely demonstrated, at least
very probable, that the Trichodesmium, which colours the
waters of the China Sea to the south of the canal of Formosa,
colours those also to the north of the same canal, and that this
phenomenon is produced on a large scale. But it is pos-
sible that this phenomenon extends further still, and that it
occupies in the sea a region limited to the south by the 15°
of latitude, and to the north by the 38°, or in other words an
extent of nearly 25°. It is quite natural to suppose that the
name of Hoang-Hai ( Yellow Sea), which the Chinese give to
the sea that washes the northern shores of China and the
western shore of the peninsula of Corea, is attributable to the
existence of similar phenomena. All geographers attribute
the colour of this sea to the existence of a yellow mud carried
into its waters by the Yellow River (Hoang-Hoe). Sir G.
Staunton, who has given us the account of Lord Macartney’s
embassy, relates that, during the voyage of the English
squadron through this sea, the vessels, although they had 6
fathoms water, carried away such a large quantity of mud that
they left a trace of yellow brown in their wake for nearly half
a mile. Now, that is precisely the appearance of the muddy
deposit which was formed in the glass where I kept the water,
the study of which forms the subject of these remarks.

All authors who have written on the geography of China,
speak of the shallowness of the Yellow Sea, and of its shoals,
formed in part of sand, and in part of the mud of which we
are speaking, the deposition of which appears to be con-
stantly going on. They cite, as an example of its rapid in-
crease, the little island of Tsung-Ming, situated at the mouth
of the Yang-tse-Kiang, This island is not marked upon the
map of China, preserved at Venice, which was drawn from
the rough draught of the celebrated traveller Marco Polo ;
whilst the island of Chusan, situated in its neighbourhood, is

72 ON THE COLORATION OF THE CHINA SEA.

to be found in it. It appears, then, probable that the island
of Tsung-Ming, formed entirely of deposits of mud and sand,
is of recent origin, and that it only existed as a shoal at the
period when Marco Polo wrote the curious recital of his voy-
ages. If, as might be thought, the mud of the Yellow Sea
were almost entirely formed by the decomposition of our
microscopical Alga, we should have a new instance of geolo-
gical formations due to microscopical organisms, the know-
ledge of which forms one of the most curious discoveries of
our times, and one of those which will contribute the most to
immortalize the name of M. Ehrenberg.

These are only conjectures, but they appear to me to possess
a certain degree of probability. I hope that our increasing
relations with China will give us before long the opportunity
of clearing up all these questions.

One more question presents itself: one of the largest rivers
in China and in the world, the Yellow River, or Hoany-Ho,
which empties its waters into the Yellow Sea, and the over-
flowing of which has played such an important part in the
history of China, since the earliest periods up to the present
day, is itself of a yellow colour.

I have looked, in works treating on the geography of China,
for some remarks on this coloration. ‘The only important
ones are to be met with in the following extract from the
Geography of Asia, by Carl Ritter :—

“« The evident meaning of the word Hoang-Ho is that of Yellow River.
It is found already 200 years A. c.; for in the Chow King, this river is
called Uoang (yellow), emblem of the earth; and Hoang-Ti, the God (7%)
upon the earth ; or, in other words, the Sovereign Master, one of the titles
of the emperor of China, as Lieutenant of the God of Heaven, Shang-77.
In the upper part of its course, as far as the place where it leaves the wall
of China, above Lautscheon, in the Kanson, the river has, like all alpine
currents, perfectly transparent waters. When it washes the country of
Ordos, it becomes muddy, of a thick yellow colour like the Tiber or the
Maine: it is from that, that it takes its Chinese name Hoang, yellow
or yellow-saffron (the missionaries call it Saffron River), as well as its
Mongolian name AKaramoran (from kara, dark, thick), under which it is
described by Marco Polo, It sometimes happens, under extraordinary
circumstances, that the water in the middle region of its course changes
its nature. It is reported in the Annals, that in the year 1295, after a
violent earthquake, the waters of the Hoang-Ho, which even at Lautcheon,
usually begin to be thick, became during three days perfectly clear and
transparent over an extent of 300 Ui, which was considered a happy
prestige, and caused many congratulations to be sent to the court. But

six months afterwards there was a ereat famine which cost the lives of
many people.”

However incomplete these documents are, they indicate the
existence of a natural phenomenon. But what is the cause of
it? Ought we to trace in it the record of microscopical vege-

ON THE LIFE AND GROWTH OF NEMATOIDS. 73

tation ? does there exist, as all geographers pretend, a relation
between the coloration of the river and the sea? I can only
place these questions before other naturalists who may have
the opportunity of exploring these interesting districts.

Nouvelles Observations sur le developpement et la vie de Nema-
toides. Par MM. Ercorant et Louis Vetta. (From the
Comptes Rendus, July 3, 1854.)

1. Tue embryos of the ovaviparous Nematoid worms do not
attain a complete development (that is to say are not furnished
with reproductive organs) in the locality in which they are
deposited by their mother, however favourable the conditions
for their development may appear. The ovaof the oviparous
Nematoid worms, as well as the embryos of the ovaviparous,
must quit the situation in which they have been deposited, and
live in a state of liberty during a certain period, for their com-
pletion on re-entering the bodies of animals.

2. The ova of certain of the Nematoidea remain stationary
in the intestinal mucus of the animals in which they were
deposited by the parent; the phases of the development of
these ova removed from the mucus ensue with great rapidity
immediately they are placed in water.

3. The development of the ova of Strongylus auricularis
(Zeder) has been obtained with tolerable facility in from two
to five days, notwithstanding the complete state of putrefaction
into which the bodies of the parent worms had fallen, and
which had been collected at the same time.

4. The embryos thus produced have lived for twenty days
in the water, but without growing or developing any repro-
ductive organs.

5. Analogous Nematoid embryos are often presented in the
little puddles of water in places where fowls are kept, and the
excrements of domestic animals are collected,

6. Certain Infusoria, referred by Ehrenberg and other natu-
ralists to the genera Vibrio and Anguillula, are nothing but
nematoid worms in the embryonic condition ; some, in fact,
belonging without doubt to the genus Oxryuris.

Such, adds the Reporter (Prince Bonaparte), are the conclu-
sions of an important memoir which the authors are hastening
to communicate to the Academy of Sciences. Naturalists, he
observes, will be struck by the analogy between the embryos
above adyerted to, and other embryos commonly found in
stagnant waters, and which have been regarded as _ perfect
animals. But how many of the putative genera of Infusoria,
he asks, should be eliminated from science? Should the

74 ON THE LIFE AND GROWTH OF NEMATOIDS.

whole class of Infusoria disappear or be split up into several ?
Such is the vast field opened to the meditations of Zoologists.

In the same number of the Comptes Rendus, M. de Quatre-
fages gives extracts of letters from M. V. Beneden, commu-
nicating the new and most important results at which he had
arrived in prosecuting his researches on the Cenurt.

M. Kuchenmeister had a dog which had been fed upon the
Cenuri of a sheep at the beginning of March, and which
passed the tenioid ‘“‘ Proglottis,” developed in its intestines
from the Cenurus.

The dog was killed on the 24th May, and M. Kuchenmeister
sent some of the Ttenie of the Cenurus to Louvain, Copen-
hagen, and to Giessen. They arrived at Louvain on the 27th,
contained in the white of egg, and were kept alive for eight
days, the white of egg being renewed daily.

On the same day (27th) at 9 a.m. two lambs, about two
months old, took each of them half a Proglottis ; in the after-
noon each took a whole Proglottis, and on the drd June one of
the lambs swallowed another whole Proglottis.

On the 13th June, the first symptoms of ‘ staggers” showed
themselves, and on the 15th one of the lambs was killed.
The head was burning hot, the eyes red; the legs bent under
the body, the animal ran with its head against the railing, and
turned round and round in one direction.

The surface of the hemispheres of the brain above and
below presented very irregular grooves, of which there were
about adozen. At the end of these tubes were found as many
Cenuri, almost all lodged in the cortical substance of the brain.
Some were removed with the membranes. These Cenuri were
constituted of a simple vesicle of a milky white colour filled
with fluid. At that stage they presented no heads (Scolex).
They represented the hexacanth embryonic form (Proscolez),
a little more developed than it is when it quits the ovum.

Yellowish-white corpuscles were subsequently found in the
muscles and especially in the diaphragm, and which could be
distinguished very well by the naked eye among the red
muscular films; and which, as stated by M. Kuchenmeister,
are nothing more than errant individuals, and incapable of
further development.

M. Eschricht gives a similar account of his experiments
with the Proglottides sent to Copenhagen, and some interest-
ing observations on the mode of development of the Scolex
form from the simple vesicle above noticed.

From Giessen, also, Leuckirt reports results of his experi-
ments with the same Proglottides, in all respects identical
with the above.

resi t)

REVIEWS.

Lectures on Hisronocy, delivered at the Royal College of Surgeons of
England in the Session 1851-52. By Joun Quexkert, Professor of
Histology. Vol. II. Bailliere. London.

In pursuance of the plan laid down in his first volume,
Professor Quekett has in this work presented us with another
instalment of the histology of organic beings. The subject
here taken up is the structure of the skeleton of plants and
invertebrate animals, Although we hope Mr. Quekettt may
be encouraged to proceed with the publication of his lectures,
we think he has very judiciously selected his present subject
as supplying a want of the physiologist and the microscopic
inquirer. The fact is, at the present day, there is little to be
added to our knowledge of the histology of the human body,
and what we really want to complete our knowledge of the
structure of organized beings, is more extended researches
upon the lower animals. Our knowledge of vegetable struc-
ture, also, is much more extensive than it is of the lower
animals. ‘To all inquirers, then, in the field of comparative
histology, this volume of Mr. Quekett’s lectures will be found
very acceptable. We cannot commend Mr. Quekett’s volume
as a comprehensive treatise upon all that is known with
regard to the hard parts of plants and invertebrate animals ;
but, like that which renders all his other writings valuable,
it bears the impress of original observation, and in all cases
the reader may rely upon the accuracy of the author. Mr.
Quekett nowhere commits himself to physiological inferences
or speculations, leaving those who follow him to form their
own opinions with regard to the functions and relations of
the parts he describes.

We shall now endeavour to give our readers an idea of the
general contents of this volume, and are enabled, through the
kindness of the publisher, to present specimens of the illus-
trations with which the work abounds. The first lecture is
devoted to some general remarks on the nature of the skeleton,
and to the skeleton of plants and sponges. The propriety of
the application of the term skeleton to any part of a plant
may, perhaps, be doubted. It is very certain that we have
no organ, or set of organs, in plants, whose homologues we
can point out in the vegetable kingdom. Every tissue in the

76 QUEKETT’S LECTURES ON HISTOLOGY.

lant, in its time, becomes hard, and to no definite combina-
tion of cells can we apply the term skeleton. Nevertheless,
the deposition of inorganic matters in the interior of the cells
of plants, in a manner resembling the process of ossification in
the animal kingdom, is a fact of great interest. Here, as in so
many other instances of vegetable structure, we see the com-
mencement of the processes which have great significance
when carried on in the animal kingdom. The following
observations on the siliceous deposits in the cells of plants
will illustrate this remark.

“‘Tn plants, as I have before stated,* inorganic salts occur in a crystal-
line form, under the name of raphides; these, however abundant, May be
regarded as accidental deposits, since it has been shown that they can be
produced by artificial means. For the benefit of those who may not have
been present on former occasions, I will give a few examples of the dermal
siliceous skeleton of plants. ”

“The first specimen is a portion of the Hqwisetwm hyemale, fig. 2, which
has been boiled for a long time in nitric acid, and not only exhibits the
cells of the cuticle, with their serrated edges, but also longitudinal rows of
oval bodies, which are the stomata. Another good example is a portion of
the husk of the Wheat, fig. 8, in which, in addition to the cells of the

Fig. 3

Ai St SoS! S.=—
a SSR
S35 2 eS 2S
TS 824, SS =
he eae =: sS
ies SY
+S) ew Se SS
Ne Shy ®&); “3s
“NS, eS, ‘ = Ss
. Se 2 ‘Ss sa:
> % SWSe
5 = =a) ‘BRS
OS
ee , wets SS
Vo JS? SU WS, 2" =
Mei HAS

Ga 2 Se SiS
—14,,; eS) So =
== : SS VS
Db re Ae = RE
A portion of the cuticle of Equi- A portion of the husk of a grain

setum hyemale, after long boiling of Wheat.

in nitric acid.

cuticle, the spiral vessels, recognized by the coiled-up fibre, also have a
skeleton of silica. In the husk of the /tice the peculiar cells of the cuticle
are seen, with bundles of woody fibre and vessels below them. The
specimen is composed entirely of silica, and there may be noticed in one
spot, where the cuticle has been torn, a series of elongated fusiform bodies,
with serrated edges, fig. 4, which are all that remain of the woody fibres,
proving that in this plant the silica is not confined to the cuticle. All
the fibres, however, are not thus serrated ; some, as represented at b, may
be seen in bundles, which are both longer and thinner than the first
mentioned, with perfectly smooth edges.

**On the upper surface of the leaf of a plant common in our gardens—
the Deutzia scabra—there are numerous stellate hairs, which much
resemble Stur-fishes in miniature, fiz. 5; these are covered with little

* Histological Leetures, Vol. L., p. 42.

QUEKETT’S LECTURES ON HISTOLOGY. 77

tubercles, each star being attached to the cuticle by its centre. If the
cuticle be removed, and boiled in nitric acid, the stellate hairs may be as

mo

PRUETT AINE UNIV

7 AW --—
ae

if

TAMA PEAT

Siliceous cuticle from
the under surface of the
leaf of Deutzia scabra.

|
Portions of woody fibres from
the husk of the Rice.

plainly seen as in the natural condition of the leaf; the crenated lines
found in all parts of the object representing the cell-walls of the cuticle.
This specimen will serve to show, which it does in a striking manner,
that silica is not confined to the cells of the cuticle, but is equally
abundant in the hairs and spines developed upon it.”

The most definite forms assumed by the hard parts of
plants, are undoubtedly those found in the Diatomacee ; but
as these have been so copiously illustrated in our pages, we
may now pass them over. The Corallines are examples of
plants having hard parts, closely resembling those to which
we do not deny the name of skeleton in animals. Professor
Quekett treats of these in his tenth lecture, with the hard parts

of Zoophytes.

“As the Lithophytes occur in the greatest abundance upon coral reefs,
where it would appear that the water is highly charged with carbonate of
lime, and, as in former times, they were considered to be Zoophytes, I
have thought proper to speak of their minute structure at this time, in
order that you may have an opportunity of comparing it with that of the
stony axis of the Corallide, and I must therefore beg of you to bear in
mind that the comparison is of the greatest interest ; for in both instances
we have a great abundance of calcareous material which has been sepa-
rated from the water by a vital process, that in the one case being effected
by a vegetable, the other by an animal basis requiring the presence of

78 QUEKETT’S LECTURES ON HISTOLOGY.

digestive sacs, or polypes, to maintain its integrity. If a vertical section
be made of any Coralline, such for example as the C. officinalis, fig. 85, a,
we shall find that, on examination with the lowest powers, it will exhibit
two kinds of structure, both of which are essentially cellular—that on the
exterior being composed of small cells of hexagonal figure, whilst in the
interior they are more elongated, and generally of a brownish colour ; this
is especially the case if a section should include a joint. In the fresh
state the contents of the cells can be easily made out, and the central ones
are not unfrequently full of greenish granules like Chlorophylle. The
lime is not in the interior of the cells, but appears to be on the outside of
the cell-walls, which are rendered opaque and thick in consequence. A
portion of the vertical section, as seen under a power of 200 diameters, is
represented at c: the dark parts on the outside of the cells there shown are
the calcareous material ; the cells in the centre, as before noticed, are of
an elongated figure, having little or no lime about them; these also are
exhibited at c, but the loose cells on the right side of the lower part of the
figure, formed part of the articulation, and are entirely destitute of lime.
A transverse section of one of the joints of the same Coralline, as shown at
b, is wholly made up of cells, those on the margin being rather larger
than the central ones; both have an abundance of lime around them, as
represented under a power of 200 diameters at d. The cells seen upon the
upper portion of this figure having been deprived of their lime, are in
consequence rendered very apparent. All the Corallines exhibit nearly
the same structure, the outer portions being composed of cells of hexagonal
ficure, and the central of elongated ones; the former are always coated
with lime, whilst the latter are only partially so, and it is by the absence
of the lime from these cells, at particular points, that the articulations are
formed.

a, a vertical section of a joint of Corallina officinalis magnified 50 diameters. 0, a transverse
section of the same. c¢, a portion of the vertical section magnified 200 diameters. d, a portion
of the transverse section magnified 200 diameters.

QUEKETT’S LECTURES ON HISTOLOGY. 79

“A very striking specimen for exhibiting the structure of the articula-
tions is Corallina incrassata ; a vertical section of this plant is represented
by « in fig. 86. The joints, as there shown, are composed of elongated
cells, and from having no lime about them, are soft and flexible, and
even of a green colour. A magnified portion of one of the joints is shown
at B, and a transverse section at Cc, both are made up of cells, of which the
central ones are much elongated. That the calcareous investment of the
Lithophytes is not a mere precipitation from the water, as happens with
many of the Characee, is, I think, very evident ; for I have never yet seen
any specimen of Coralline in which the part forming the articulation was
coated over, nor has any section shown that the calcareous matter is ever
present except as a coating to the cell-walls or the spaces between them.
In the Nullipores, which have no joints, the cellular structure is of the
same nature throughout; there are no elongated cells in the centre, as in
the Corallines, consequently it would appear that the articulation is the
result of a vital action in some of these cells, whereby they are deprived
of the power of selecting a calcareous coating from the surrounding water,
their energies being entirely devoted to the function of growth.”

The lectures devoted to the Sponges contain a large number
of illustrations of the peculiar forms assumed by the siliceous,
calcareous, and cartilaginous matters of which their hard
parts are composed. As illustrative of some of the forms
assumed by spicula in sponge, we extract the following :—

“Other spicula are very peculiar, consisting of a central portion, or
shaft, the extremities of which are furnished with two or three branches,
each of these again subdividing into two or three still smaller branches.
These spicula interlace with each other, and produce a sort of coarse net-
work; they are generally found in small sponges, attached to masses of
coral ; two specimens of the largest kind are shown at g g, in fig. 14. In

Fig. 86.

SS
i
Wulutehity

oe

0

y aK

A, a vertical section of Corallina incrassata, showing the joints. 3, a portion of one of the
joints. ©, a transverse section of the same, both magnified 130 diameters.

80 QUEKETT’S LECTURES ON HISTOLOGY.

the same sponge were others of smaller size, and with fewer branches, as
represented by d, e, and f: to such spicula the term branched may be well
applied. Another sponge contains spicula of the form I have termed
tuberculated ; they are of large size, and covered with rows of flattened
tubercles, as shown at c, in fig. 14. The sponges to which they naturally

Fig, 14.

a, bi-curvate spiculaum; b, curved spiculum; c, tuberculated spiculum ; d, e, /. g g, branched
spicula; h, bi-curvate anchorate spicula; 7, stellate spicula; /, 1, m, multi-radiate spicula.

belong I have never seen, but all my specimens were obtained from the
root of an Aleyonium, Aleyoniwm favosum, from Sumatra, and were mixed
with grains of sand and spicula of various kinds, from other sponges. A
similar species, from a different part of the world, in the possession of a
friend, when boiled in nitric acid yielded spicula of precisely the same
kind; so much so, that when a specimen was shown me, I pronounced
from whence it came.

“The siliceous remains of a small sponge, attached to the root of a
Gorgonia, Isis ochracea, I found extremely rich in peculiar forms of
spicula. The most striking was of a reticular figure, covered with minute
spines, as shown at A, in fig. 15. It forcibly reminded me of the siliceous
skeleton of the Dictyochalix pumiceus, before alluded to, and probably
may be a portion of a siliceous sponge. Other spicula occur in the same
specimen, the most remarkable of these are in the form of scales, as shown
at B, 6, EB; they may be known by their flattened figure, and by having
black dots in the centre. The edges of some of these spicula are smooth,
but in most cases they are serrated. Another very singular form of
spiculum is also found in the same sponge: it is of small size, and pin-
shaped at one extremity, and at the other is rounded, but in the centre of
the rotundity there is a short conical spine; two of these spicula are
shown at pp. Spicula of the shape termed ewrved are occasionally met
with in certain small sponges; one of these, of peculiar figure, is repre-
sented at 6, in fig. 14. In another sponge from the South Seas, bi-curvate
spicula, of the shape shown at a, are very common. Mr. Shadbolt, how-
ever, has detected some still more curious spicula than these last; they

= QUEKETT’S LECTURES ON HISTOLOGY. 81

are twice curved, like that shown at a, but each extremity is expanded, so
as to resemble the fluke of an anchor; to such form, the term bi-curvate

Fig. 15.

A, portion of the skeleton of a siliceous sponge. B,C, E, flattened spicula. pp, pin-shaped
spicula. rF, tri-radiate spicula in Grantia compressa. H, granules of sand imbedded in horny

fibre of Dysidea.

anchorate has been given; two of these spicula are represented at h. The
sponge in which they occurred, like that of the preceding, was of small
size, and brought from the South Seas.”

From the skeletons of Sponges we pass to those of Diato-
macee, Desmidiew, Foraminifera, and Nummulites. The fol-
lowing observations on the structure of Oolitic rocks are not
perhaps generally known.

«Before I leave this part of my subject, I must say a few words on the
Oolites, which were formerly supposed to consist of the remains of
organized beings of a globular figure, like the roe or eggs of fishes, but
which are usually nothing more than grains of sand, each surrounded by a
globular deposit of carbonate of lime and cemented together so as to form
masses of limestone rock. The Oolites make up no inconsiderable part of
the strata of this island; according to Ure,* they form a zone 30 miles
broad in England, and are divided by geologists into the upper, middle,
and lower Oolites. They furnish a most valuable material for archi-
tectural purposes; and are exceedingly rich in fossil remains, especially
those of reptiles and corals.

“The egg-like particles vary considerably in size, being in some cases
almost invisible to the naked eye, whilst in others they are nearly as
large as peas; this last form of Oolite has received the name of Pisolite,
differing, however, from the true Oolites only in the relative size of the
globular concretions. Bath stone, Portland stone, and the slate of Stones-
field, near Oxford, are all examples of Oolite. In fig. 52, a, is represented
a portion of that form of Oolite termed Pisolite of its natural size; the

* Dict. of Arts and Manufactures, Art. Oolite.
VOL, III. G

82 QUEKETT’S LECTURES ON HISTOLOGY.

granules are }th of an inch in diameter, one of them, shown in section at
0, is magnified 12 diameters, and the concentric lamina of which it is
composed are well displayed.

“In Germany there is an Oolite in which the granules are nearly as
large as they are in the Pisolite, but the concentric laminated arrange-
ment, as shown at p, and the presence of a central nucleus, are more
strongly marked; the rock supporting the Britannia bridge is a firm
Oolite, in which the granules are remarkably small, those represented by
B being magnified 40 diameters. The specimens just described are all
very compact, the granules being firmly cemented together by the cal-
careous material forming the matrix: it sometimes happens, however, in
oolitic districts, that the granules are separated from the matrix, and the
soil will be seen to be in a great measure made up of them. ‘This is
especially the case in the neighbourhood of Bath ; the soil of High Barrow
Hill, I found to be so rich in oolitic granules, that when turned up by the
plough, it appeared as if thickly sown with minute yellow seeds.”

Fig. 52.

A, Portion of oolite termed Roe-stone or Pisolite. 3B, Granules from Britannia rock, magnified
40 diameters. c, Granule of Pisolite magnified 12 diameters. bp, Granule of Oolite from
Germany, magnified 20 diameters.

After the examination of the Nummulites, &c., we come to
the great group of Zoophytes. These occupy several lectures,
and contain many valuable observations. The structure of
the skeleton of the Echinodermata is then gone into very
carefully. From this part of the work we extract the following
passage on the very curious bodies called Pedicellarieze :-—

““We now come to other organs found upon the external surface of
some of the Echinodermata, and these are the curious bodies termed
Pedicellaric. They were first described by Muller the Danish naturalist,
and have been since investigated by Sars, a Norwegian clergyman.
Muller believed them to be parasites, whilst Dr. Sharpey and others
regard them as parts of the animal, which they undoubtedly are. On
most HEchini there are three kinds of Pedicellariz ; being considered as
distinct animals, they have been termed Pedicedlaria tridens, Pedicellaria
triphylla, and Pedicellaria globifera, according to their form; but what-
ever this may be, each consists of a solid part, or skeleton, and a soft

QUEKETT’S LECTURES ON HISTOLOGY. 83

transparent flesh. The skeleton, as shown in fig. 140, is composed of
three calcareous jaws, having a sharp recurved tooth at the apex and an
internal serrated edge, while the tissue surrounding the jaws is strength-
ened by minute bicurvate spicula; it is seated on a cylindrical stalk
placed in the centre of the fleshy stem.

“ All these parts, when highly magnified, present the characteristic
structure of the shell of the animal; the soft tissue, on the contrary, is
transparent, contractile, and, like that of the cirrhi, is capable of con-
siderable elongation and flexion. While the Echinus is living, the
Pedicellariz are always in active movement from side tv side, the jaws
are continually opening and shutting, and if a small body be placed within
them, it is held with tolerable force. They are attached to the soft fleshy
covering of the shell by a dilated base, and are not confined to any par-
ticular part of the shell, but many may be seen on the thin membrane
closing the oral aperture. ‘The part which I have called the stalk is
somewhat dilated at each extremity ; its structure resembles that of a
small spine, and it is stated by Sars that each stalk, like a spine, is
articulated to a minute tubercle; but of the truth of this I have never yet
been able to satisfy myself, as in all cases after their removal the soft
stem has been found to completely invest the whole of the calcareous
matter.

“Tf the Pedicellariz be removed from the Echinus, they will continue
in active movement for some time, and if one of them be touched with a
needle or pin, those in the neighbourhood will all bend towards the one
that has been irritated. In the Asteriadw the Pedicellarie are of a
different form to those in the Echini—in the Asterias rubens, for example,
in which they are very abundant, as shown at a a, in fig. 109, the
calcareous jaws are like the two valves of a
mussel, as represented at b, in fig. 140, two of
the edges being serrated, whilst the other two,
which are not closely approximated, have a
semicircular notch, leaving an opening between
them when in apposition, and the stem is short
and flexible, but not provided with a calcareous
axis as in the Echinide. When magnified
130 diameters, as shown at ¢c, the characteristic
reticulated structure is exhibited. Mounted
specimens, taken from the outer surface of the
shell of Hchinus miliaris, as represented at a,
in fig. 140, show very distinctly the three jaws
and the axis or stalk, but being in a state of
contraction, the soft parts appear very short
and puckered up, so that a species of neck is
formed between the jaws and the axis; this,
however, is not the case in living specimens.
All the parts composing the skeleton of the
Pedicellarie exhibit the characteristic reticu-
lated structure of the Echinodermata. The. carts, 4 auelelon, OF one. oF
jaws are thin, flattened below, sharp above, the Pedicellarie of Asteria
and bent nearly at right angles, so as to forma ‘7wbens. c, portion of the
tooth; the axis is about ith of an inch in SMcleion of the same magnified
length and dilated at both extremities, and in
shape and structure is very like the spine of an Kchinus. On either side
of the jaws may be seen a row of small bicurvate spicula, somewhat
resembling those in the disc of the cirrhi of the Echinide, but differing
from them, as represented at d, in Plate XIV., fig. 19, of the first volume

G2

Fig. 140.

84 QUEKETT’S LECTURES ON HISTOLOGY.

of the ‘ Histological Catalogue,’ in having more than one hooked process
extending outwards from the point where the curved portion commences.
Under a power of 40 diameters, as shown at a, in fig. 109, numerous
: Pedicellariz are distinctly visible on the
Fig. 141. upper dermal surface of Asterias rubens, even
after having been dried ; but as the soft fleshy
stalk is very short and has no calcareous
axis, little can be seen except the jaws.
Pedicellarize also exist in the Spatangi, but
they are not so evident as in the Echini; the
principal varieties found in S. purpureus,
according to Forbes, are represented in
fig. 141.

“The Pedicellarie then, without doubt,
belong to the animal on which they are
found; they are not parasites, but it is diffi-
cult to determine their true office; they are
probably useful in keeping the shell free from all intruders of a parasitic
nature, and may be supposed to perform an analogous function to that of
the so-called ‘ Bird’s-head processes’ of the Bryozoa.”

Pedicellarie of Spatangus
purpureus

The Mollusca and Articulata are treated of after the
Echinodermata. The shells of the principal families of the
Mollusca are examined in detail, and many new points in
their structure described and illustrated. The Articulata are
not treated so much in detail. In these concluding lectures
we had marked some passages which we should have liked
to have transferred to our pages. We have, however, given
sufficient for our readers to form an estimate of the work,
which we are sure will be of such a kind as to lead them
to feel that it is one of great value to the microscopical
student. The illustrations are very copious, and every one
will be able to form an opinion of their excellence from those
we have given above.

,

CP BoHg)

NOTES AND CORRESPONDENCE.

On the Aperture of Object-glasses.— It appears to me that your
correspondents on the subject of the aperture of object-glasses
for microscopes, and the methods of measuring the same,
have left the simple means of ascertaining the angle of aper-
ture, and taken up with such complex methods, that they
have been led into very considerable errors; and hence the
erroneous results, in my opinion, of Professor Robinson and
Mr. Wenham, particularly with regard to objects mounted in
balsam. My method of measuring the angle of aperture is,
to use the object-glass of the microscope as the objective of a
diminishing telescope, making use of a single lens of an inch
and a half focus for the eye-piece of the telescope, and then
fixing this little telescope on a divided circle with the focus
of the objective over the centre of the circle, or else by placing
two candles so that each of them may be at the extreme edge
of the field of view of the telescope. In the first case, the
angle of aperture is accurately measured by the circle, when
the image of the flame of a distant lamp or candle is made to
traverse the field of view of the telescope ; in the second case,
lines drawn from the objective to the two candles form the
angle of aperture, which may be easily measured by a com-
mon protractor. Now, by taking either of those methods,
and measuring the angle of aperture with nothing intervening,
with a slider containing an object mounted dry, or one with
an object mounted in balsam ; the results were (as they ought
to be from the laws of light) in all cases exactly the same.
Had Professor Robinson’s and Mr. Wenham’s results, with
regard to balsam-mounted objects, been correct, the two
candles placed at the extreme edge of the field of view, in a
lens of 150° of aperture, would have required to have been
brought more than four times as near together,* when the
slider with the balsam-mounted object was interposed, as
when it was not; but the candles did not require moving, but
remained at the edge of the field, whether the slider was
there or absent. Again, two sliders were taken of exactly the
same thickness, the one containing objects mounted dry, the
other objects mounted in balsam; one of these being placed
on the stage of the microscope, was illuminated with such

* The proportion of the tangents of 75° and 40°, or half the angle of
aperture.

86 MEMORANDA,

extreme oblique light, that only one-half of the field of view
of the microscope was illuminated; the line of demarcation
between the illuminated part of the field and the black-ground
part, passing directly through the centre of the field, and this
division of the field remained constant when no slider was on
the stage, when the one with the objects mounted dry was
placed there, and when the one with the balsam-mounted
objects was used. Had the angle of aperture been at all
altered or lessened, by the interposition of the sliders, it must
instantly have become visible by the change of illumination
in the field of view of the microscope.

When I first read the account of the results obtained by
Professor Robinson and Mr. Wenham, it struck me forcibly
that they must have committed some great error; for, in
experiments with the fine linear objects, I had never been
able to see the markings on the NV. rhomboides with an angle
of less than 120°, when it was mounted dry: now, if it cannot
be seen with less than 120° when mounted dry, it would be
impossible with any angle to see the markings on it when
mounted in balsam; as an angle of 150° (according to the
results given in your Journal) would be reduced to less than
80° when employed to examine an object in balsam; but in
opposition to this, I always consider that with my 1-12th of
150° of aperture, I can see the markings on WN. rhomboides
better in those specimens which I have in balsam, than in
those which are mounted dry; and Mr. Wenham himself
stated to me that he had never seen the markings on JV.
rhomboides so well as he saw them on one of my dry speci-
mens, and yet at least they are equally as distinct on those
which I have in balsam. I should advise both Professor
Robinson and Mr. Wenham to go over their experiments
once more, and | think they will be able to determine how

they have fallen into error.—J. D. Soturrr, Grammar-School,
Hull.

Hilumination of lWicroscopic Objects.— | beg permission to
insert in the next number of the ‘ Quarterly Journal of Micro-
scopical Science’ a short comment on Mr. Rainey’s remarks on
my paper on microscopic illumination. I have no desire to
raise a controversy that must in the end be perfectly useless,
but as Mr. Rainey misquotes my sentences, and implies that
Iam ‘“ dogmatical,” a few words in reply may perhaps be
allowed, with the understanding that I feel all due deference
and respect for My. Rainey’s long experience as a micro-
scopical observer.

In the first place, where can be the “ ambiguity and com-

MEMORANDA. 87

plexity” of my assertion, that light cannot be totally reflected
either externally or internally from refracting bodies with
parallel sides, when this is a well-known and simple optical
fact, yet Mr. Rainey again states that the fotal reflection he
alludes to “is supposed to be from one surface only, namely,
from that on which the rays are incident ?”

I have stated that the undulatory theory of light has very
litile or nothing to do with the illumination of microscopic
objects. Mr. Rainey has cleverly turned these four short
words, and assumed that I, with great presumption, have
ventured to deny the undulatory theory being a correct one,
and then proceeds to argue and defend the case as if I had
really done so. My meaning (which will be easily under-
stood by referring to my paper) was simply this.—When we
view a house, a tree, or a distant landscape, I think that it
will be admitted that there is no occasion to refer to the un-
dulatory theory to account for their visibility. The same
reasoning may also be applied to objects of minute size, as the
point of a needle, fibres of a piece of textile fabric. All these
conditions are still in existence when a magnifying lens is
used, which in effect merely serves to shorten the focus of the
eye. I cannot see the utility of attempting to endow minute
objects with exclusive properties when under the microscope ;
their illumination and visibility are simply a question of quality
and direction of light, the same as in all ordinary cases,

Mr. Rainey will, I trust, pardon me for stating that I have
not “invented any new theories” to explain the action of my
parabolic condenser, for, to use his own words, “ these facts
allow of an easy and obvious explanation upon long-esta-
blished principles.” The whole of this implied theory rests
upon mywmaking use of the term “ radiated light.” If Mr.
Rainey will distinctly contradict the fact, that an illuminated
atom does in reality radiate light in all directions, I shall be
better able to answer the question.

I must remonstrate against Mr. Rainey’s assertion that I
myself “ evince great dissatisfaction with the term radiated
light.” This refers to a note at the end of my paper, stating
that I had adopted the term because it was descriptive and
convenient, though perhaps not philosophically correct. Mr.
Rainey’s application of this remark only serves to show me
that this isan admission that I ought not to have made.—F. H.
WenuaM.

New Achromatic Condenser.— Having invented a new kind of
achromatic condenser of general utility, for all kinds of illu-
mination, and finding it much superior to anything of the

88 MEMORANDA.

kind I have yet seen, I feel desirous that others should avail
themselves of the advantages attendant on its application to
the microscope.

This condenser consists of two achromatic lenses, one of
four and the other of two inches focus. The four-inch lens
has an aperture of an inch and a quarter, the two-inch lens
an aperture of three-quarters of an inch; they are placed at
one inch and three quarters asunder, and the compound focus
is an inch beyond the smaller lens. This condenser is placed
below the stage of the microscope, but contrived to revolve in
the arc of a circle, so as to vary its position from perfectly
direct light, to the greatest obliquity of position that may be
required for illuminating the most delicate linen objects. Its
distance from the stage when used with the higher powers
being such, that in every position a perfectly well-defined
image, either of the flame of the lamp, or the bars of the
distant window, is depicted on the slider holding the object.
The two achromatic object-glasses, which form the condenser,
require to be accurately made, and when so formed the light
from it is most intense and of the purest kind, at the same
time producing a degree of definition superior to that of any
other method of illumination that I have seen: in addition to
this, the illumination is equally perfect for the most oblique
light; so much so, that when the axis of the condenser is
inclined to the axis of the microscope, for the most extreme
angle required with lenses of 150° of aperture, there does not
appear any diminution either of light or definition.

For microscopes furnished with this condenser no concave
mirror would be required ; and for iliumination with the low
powers it is only necessary to slide the condenser further from
the object, so as to illuminate it by a broader part of the pencil
of light.

The light may be either admitted directly through the con-
denser, or reflected through it by means of a plain mirror.
By the use of this condenser I have resolved many of tbe
delicate test-objects with a 1-4th of an inch lens of 95° of
aperture, that would be found under ordinary illuminations
very difficult to resolve with a 1-8th object-glass and 130° of
aperture.

The two lenses used in this condenser are constructed on
the same principle as all achromatic combinations for the
inicroscope, their plain sides being turned towards the object,
and the wider lens of course placed next the light. A good
workman will easily contrive an elegant method of fixing the
condenser to the microscope, and it may be adapted so that
the axis of the condenser may be brought to the required angle

MEMORANDA. 89

with the axis of the microscope, by rack-and-pinion movement,
as well as varied in its distance from the stage by the same kind
of motion. It may be further observed that when the angle,
which the axis of the condenser makes with the axis of the
microscope, is greater than half the angle of aperture of the
object-glass, the black-ground illumination is produced in the
most perfect manner. Provided this condenser be attached
to the stage of the microscope by a circular arc divided into
degrees, the angle of aperture of the object-glass under all
conditions can be accurately ascertained, for the limit of aper-
ture will be when the illuminated field is just passing into
the black-ground illumination.—J. D. Soturrr, Grammar-

School, Hull.

Wlicroscopical Examination of Deep Soundings from the Atlantic
@cean.—The soundings examined were as follows :—

1080 fathoms, Latitude 42° 04’ North, Longitude 29° 00’ West, July 25, 1853.

seo”: hile? ees leans & Pe EM ad Mast igh
1580 ,, 5» 49° 56’ 30” ag 13° 30 45” Aug. 22 ,,
SOOKE Ss ots AT e BBb eh ig 15 09° 08' ,, No date.
2000 ,, i coi Bile Benge - 22° 33’ ,, a

As these soundings are believed to be the deepest ever
submitted to microscopic examination, and were obtained at
localities far remote from those previously noticed, they were
studied very carefully, and the following are the facts ascer-
tained :—

1. None of these soundings contain a particle of gravel,
sand, or other recognizable unorganized mineral matter,

2. They all agree in being almost entirely made up of the
caleareous shells of minute, or microscopic Foraminifera
(Polythalamia, Ehr.), among which the species of Globigerina
greatly predominate in all the specimens, while Orbulina uni-
versa, D’Orb., is in immense numbers in some of the sound-
ings, and particularly abundant in that from 1,800 fathoms.

3. They all contain a few specimens of non-parasitic or
pelagic Diatoms, among which Céscinodiscus lineatus, C. ex-
centricus, and C. radiatus of Ehrenberg, are much the most
abundant.

4. They all contain a few siliceous skeletons of Polycis-
tines, among which are several species of Haliomma, Litho-
campe, &c.

5. They all contain spicules of sponges, and a few speci-
mens of Dictyocha fibula, Ehr.

6. The above-mentioned organic bodies constitute almost
the entire mass of soundings, being mingled only with a fine
calcareous mud derived from the disintegration of the shells.

90 MEMORANDA.

7. These soundings contain no species of Foraminifera
belonging to the group of Agathistegues (Plicatilia, Ehr.), a
group mluick appears to be confined to shallow waters, and
which in the fossil state first appears in the tertiary, where it
abounds.

8. These soundings agree with the deep soundings off the
coast of the United States, in the presence and predominance
of species of the genus Globigerina, and in the presence of the
cosmopolite species of the Orbulina universa, D’Orb., but
they contain no traces of the Marginulina Bacheii, fie, Textilaria
Atlantica, B., and other species characteristic of the soundings
of the western Atlantic.

9. Examined by chromatic polarized light, the foramini-
ferous shells in these soundings showed beautiful coloured
crosses in their cells, and the mud accompanying them also
became coloured, showing that it is not an amorphous che-
mical precipitate. It in fact can be traced, through fragments
of various sizes, to the perfect shells of the Foraminifere.

10. In the vast amount of pelagic Foraminifere, and in the
entire absence of sand, these soundings strikingly resemble
the chalk of England, as well as the calcareous marls of the
Upper Missouri, and this would seem to indicate that these
also were deep-sea deposits. The cretaceous deposits of
New Jersey present no resemblance to these soundings, and
are doubtless littoral, as stated by Prof. H. D. Rogers (Proc.
Bost. Soc. Nat. Hist. 1853, p. 297).*

11. The examination of a sounding, 175 fathoms in depth,
made in latitude 42° 43’ 30” N., longitude 50° 05’ 45” W.
(near Bank of Newfoundland), by Lieut. Berryman, gave
results singularly different from those above stated. It proved
to be made up of quartzose sand, with a few particles of horn-
blende, and not a trace of any organic form could be detected
in it. This exceptional result is important, as it proves that
the distribution of the organic forms depends on something
else beside the depth of the water.

12. Connecting the results above mentioned with those fur-
nished by the soundings made in the western portions of the
Atlantic, it appears that, with the one exception above men-
tioned, the bottom of the North Atlantic Ocean, as far as
examined, from the depth of about 60 fathoms, to that of more
than two miles (2,000 fathoms), is literally nothing but a mass
of miscroscopic shells.

13. The examination of a large number of specimens of
ocean water taken at different depths by Lieut. Berryman, at

situations in close proximity to the places where the sound-

* American Journal of Science and Arts.

MEMORANDA. 9]

ings were made, shows that even in the summer months, when
animal life is most abundant, neither the surface water, nor
that of any depth collected, contained a trace of any hard-
shelled animalcules. The animals present, some of which are
even now alive in the bottles, are all of a soft, perishable
nature, leaving on their decay only a light flocculent matter,
while the Foraminiferee and Diatoms would have left their
hard shells if they had been present.

As the species whose shells now compose the bottom of the
Atlantic Ocean have not been found living in the surface
waters, nor in shallow water along the shore, the question
arises, Do they live on the bottom at the immense depths
where they are found, or are they borne by submarine currents
from their real habitat? Has the Gulf-stream any connection
by means of its temperature or its current with their distribu-
tion? ‘The determination of these and other important ques-
tions connected with this subject requires many additional
observations to be made. It is hoped that the results already
obtained will induce scientific commanders and travellers to
spare no pains in collecting deep-sea soundings. If such
materials are sent either to Lieut. Maury, U. S. Observatory,
or to myself at West Point, N. Y., they will be thankfully
received and carefully studied.—J. W. Battry.

On some new Localities of Fossil Diatomacez.—Some interesting
specimens of fossil Diatomaceze from California and Oregon
having come into my possession, I am induced to publish the
following brief notices of them, in hopes to direct the atten-
tion of travellers in those regions to those remarkable deposits,
and thus acquire more information concerning their position
and extent.

1. The first specimen of fossil Diatomacee from California,
I found among specimens of minerals collected two or three
years ago in California by Washington Chilton, Esq., of New
York. its was from Suisun Bay, 25 to 30 aie above St.
Francisco, where Mr. Chilton says a large bed of similar ma-
terial exists. It consists of a light white clay-like substance
made up entirely of fossil marine Diatoms, many species of
which are identical with species occurring fossil in the tertiary
diatomaceous deposits of Virginia and Maryland, while a
number of the species found in these latter deposits do not
occur in the California beds.

2. In a box of minerals, collected in Oregon and California
by Lieut. Robert Williamson) of the U. S. Topographical
Engineers, | found four specimens of fossil diatomaceous
ae ey idently from different localities, although unfortu-

92 MEMORANDA.

nately the precise locality is mentioned for but two of the spe-
cimens. I will designate them as specimens A, B, C, and D.

Specimen A.—This is a very light white substance, made
up of the siliceous shells of fluviatile Diatoms. The predo-
minant species are a small Gallionella and a Discoplea, mingled
with a few species of Epithemia, Cocconema, Gomphonema,
and Spongiolites. This specimen was without a label, but is
believed to be the specimen referred to in the following
extract from a letter received from Lieut. Williamson :—‘“ You
will find some of the light white clay from Pit River, which
I spoke of to you.” ‘This is, I believe, the same substance
which has given rise to the newspaper accounts of cliffs in
California composed of carbonate of magnesia.

Specimen B.—This is a light white chalky mass, whose
locality is not given. It consists of fluviatile species, among
which various species of Biblarium are quite abundant. The
species of this genus have been found living in Siberia, and
fossil in Oregon. Lieut. Williamson’s specimen resembles
the Oregon mass found by the U.S. Explormg Expedition
under Captain Wilkes, but presents a different group of forms
and therefore must be from a different locality.

Specimen C._—This is also a chalk-like mass, whose precise
locality is not .marked. It is composed chiefly of a minute
species of Gallionella, mingled with sieve-like discs, which at
first would be referred to the marine genus Coscinodiscus ; but
the entire absence of all other marine forms, and the presence
of several decidedly fluviatile species, make me believe that
the deposit is a fresh-water one, and careful examination of
these discs show that they are more nearly allied to the fresh-
water genus Stephanodiscus than to the marine Coscinodiscus.

Specimen JD.—I\s an ash-coloured earth, marked as from
near the Boiling Spring, Pit River. It is chiefly remarkable
for containing a great number of Phytolitharia, or remains of
the siliceous portions of plants, mingled however with nu-
merous minute fluviatile Diatoms.

It is hoped that travellers in California and Oregon will
keep a look-out for specimens of light white clay-like sub-
stances, and carefully marking the locality at the time of collec-
tion, send them to me for microscopic examination. Even a
minute portion sent by mail will be very acceptable.—
J. W. Baitey.— American Journal of Sciences.

Powell and Lealand’s New Condenser.—In the last October
number of the ‘ Microscopical Journal,’ I observed a notice
of Powell and Lealand’s new condenser, by Dr. Inman of
Liverpool, in which he mentions his having demonstrated the

MEMORANDA. 93

markings on the Ceratoneis fasciolata (Pleurosigma fasciola),
by means of using a 1-8th-inch object-glass, which power
I presume he considered necessary for that purpose. I have
now the pleasure of stating that with the same kind of con-
denser, but with one of Powell’s recently-made 1-4th-inch
objectives, [ have brought out the markings of this species in
the most satisfactory manner; also with the same power the
markings, rather difficult of detection, of the Pleurosigma
delicatulum, intermedium, nubicula and Afstuarii, and of Nitz-
schia sigmoidea, using, however, in place of the achromater,
Shadbolt’s Annular Condenser, with the light direct from the
lamp—a method of illumination which seems to be especially
adapted to the demonstration of delicate test objects. The
same result has been obtained, but [ think in a more perfect
manner, by means of the prism furnished by Powell and Lea-
land, which should be so adjusted for this purpose as to give
the object illuminated on a perfectly black field.

The above facts may be interesting to some of your readers,
should you deem them worthy of insertion in the next number
of your Journal.—E. Breaxrey, M.D., Norwich.

New Species of Diatomacee.— The species of Diatomaceze
here described as new, together with others, were detected
either as parasites upon Alga, or entangled in mud adhering
to shells, Alge, &c., brought home by the Exploring Expe-
dition under the command of Capt. Wilkes, U.S.N.

1. Amphitetras favosa, Harvey et Bailey. Loricis tabulari-
bus; lateribus vix concavis, primario; secundario quadran-
gulo, angulis fere rectis vix productis, superfice cellulis magnis
hexagonis tessellata. ab. Mindanao.

2. Amphitetras Wilkesii, H. et B.; loricis prismatico-tabu-
laribus, lateribus concavis, primario longitudinaliter striato-
punctato medio transversim zonato; secundario quadrangulo,
angulis productis rotundatis, superficie cellulis minutis in
lineas simplices furcatasque dispositis notata, prominentiis
jugalibus punctulatis. Hab. Puget’s Sound.

3. Aulacodiscus Oreganus, H. et B.; lorica prominentiis
redecim intramarginalibus instructa, a quibus tot radii fere
ad umbonem procurrent ; superficie preter umbonem glaberri-
mum, minute punctata iridescente. Hab. Puget’s Sound.

4. Campylodiscus Kiitzingii, H. et B.; sellaformis, late
marginata, sulcis subquinquaginta transversis continuis curvatis
impressa. Hab. Mindanao.

5. Cocconeis parmula, H. et B.; late elliptica, linea media
longitudinali notata, utroque latere costis (vel sulcis) trans-

94 MEMORANDA.

versis magnis 10-12 irregularibus impressa; superficie trans-
versim striato-granulata. Hab. Tahiti.

6. Cocconeis rhombifera, H. et B.; late elliptica vel sub-
orbicularis, linea media oblique-longitudinali sigmoidea
areolam glabratam percurrente qua apice et basi attenuata
est, et versus umbonem in rhombi formam ampliata; super-
ficie decussatim et transversim punctataé. Hab. Puget’s Sound.

7. Cocconeis sulcata, H. et B.; late elliptica vel suborbicu-
laris, transversim sulcata, sulcis 30-40 arcuatis.. Hab. Puget’s
Sound.

8. Hyalosira punctata, H. et B.; loricis magnis in catenas
longas co-ordinatis rectangulis subquadratis transversim inter-
rupté vittatis ; vittis medio lorice alternantibus granulatis,
alternis serie punctarum insignium ornatis. Hab. Tahiti.

9. Isthmia minima, H. et B.; zona transversali subtilissime
decussatim punctata, lateribus (secundariis) cellulis magnis
granulata. Hab. Rio Janeiro and Sooloo Sea.

10. Triceratium coneavum, H. et B.; lorica lateribus valde
concavis angulis rotundatis, superficie triquetra cellulis minutis
in lineas radiantes simplices furcatasque co-ordinatis notata ;
prominentiis jugalibus punctulatis. Hab. Tahiti.

1]. Triceratium gibbosum, H. et. B.; parvum, fere inflato-
globosum, lateribus valde convexis, angulis prominentibus,
superficie ut in T. concavum notata. Hab. Tahiti.

12. Triceratium orientale, H. et B.; magnum; lateribus
convexis angulis productis obtusis, superficie triquetra cellulis
magnis hexagonis favosa. Hab. Mindanao.

13. Triceratium Witkesii, H. et B.; lorica lateribus con-
vexiusculis angulis rotundatis, superficie ut in 7. concavum
notata. Hab. Puget’s Sound.

APPENDIX.

14. Lagena Williamsoni, H. et B.; testa bicellulosa, cellulis
diversis, inferiore ellipsoidea longitudinaliter costata in isth-
mum infundibuliformem attenuata, et ad cellulam superiorem
glabram semi-lageneformem (vel inverse infundibuliformem)
ferruminata ; collo breviusculo recto, ore subampliato. Hab.
Mindanao.—Professor W. H. Harvey and Professor J. W.
Barney, in Proceedings of Academy of Nat. Sciences, Phil.
Oct., 1853.

( 95)

PROCEEDINGS OF SOCIETIES.

GEOLOGICAL SOCIETY.

On the Microscopical Structure of Freshwater Marls and Lime-
stones. By H. Cuirron Sorsey, F.G.S.

Tue author first described the general conclusions he had arrived at
with respect to the condition of the mineral portion of calcareous
organisms, which he considered is first deposited in the form of
crystalline granules of variable size, that afterwards undergo more or
less of erystalline coalescence. In some cases this scarcely occurs at
all; but in others it does to a very considerable extent during the life
of the organism, and this produces a great difference in the character
of the particles into which it is resolved by decay. The falling to
powder that then takes place is the result of the oxidization and
removal of the organic portion, and, if no crystalline coalescence
had occurred, the shell or other body might be resolved into the very
minute, ultimate, crystalline granules ; whereas, if much coalescence
had taken place, it would break up into much larger ones, showing
in many instances its minute organic structure.

The particular forms of the particles into which the Limnzans
and Paludine, found so plentifully in many fresh-water marls, are
resolved by decay, were then described and shown to present such
definite characters as to render it easy to distinguish them with cer-
tainty from most others at all likely to occur in them. Soft, loose
marls can of course be investigated by mixing the particles in water;
but thin sections of harder limestones must be prepared, and the facts
which may be learned from them are in many respects very superior ;
and from them the relative proportion of the various constituents
may be determined with great accuracy, by carefully drawing their
outline on strong even paper with a camera lucida, and afterwards
cutting out the several portions and weighing them. This method
the author terms ‘ physical analysis.” To fully describe all the
necessary particulars would occupy too much space for this abstract ;
but, by attending to them, very great accuracy may be attained, and
the true physical constitution of the specimen stated in a manner
quite different from what could be ascertained by chemical analysis,
which, for the purpose of these inquiries, is often greatly inferior,
though often most valuable in addition.

Proceeding to the application of these methods of research to
particular cases, some white marly deposits found in some of
the filled-up lakes of Holderness were described, and shown to be
composed of such particles as result from the decay of Bithinia
tentaculata, mixed with a small but variable proportion of such as
are derived from decayed Limneans. In confirmation of this it
may be stated, that though no entire shells are found in them, yet

96 PROCEEDINGS OF SOCIETIES.

numerous opercula of the Bithinia occur, which therefore appear to
have been Jess prone to decay than the shells themselves. Other
similar marls of post-tertiary age were also described, and shown to
have resulted from the decay of similar shells in variable proportion.

The soft marly portions of the Isle of Wight tertiary fresh-water
limestone were stated to be of precisely the same nature as the above,
being composed of such particles as result from the decay of Lim-
nzeans, in which term are included Limneus and Planorbis. The
examination of thin sections of the harder varieties of the same
limestone also shows that they were derived from the same source,
mixed with a variable, sometimes very large proportion of fragments
of Charz; but they have undergone more or less of crystalline
consolidation. As examples of them, two physical analyses may be
given of specimens from Binsted, which will also serve to show the
character of such analyses.

1. A hard, marly-looking specimen, with numerous cavities due
to the removal of the shelly matter of more or less entire Limnzans :

Empty cavities : 5 4 4 «2 h6a8
Fragments of Limneans . 5 3 . _ Lose
Fragments of Chara 4 11°0
Bing grains of decayed Tianeane and Chara 57:0
Peroxide of iron’ - A 4 ; 3 |

100°0

2. A hard, even-grained specimen, with no entire or large frag-
ments of shells visible to the naked eye:

Grains of Limnzan shell showing structure 3 gf 18-0

Ditto not showing ditto : fu ie
Crystallized fine eranules of shell, &e. ‘ BE)
Quartz sand F 2 13°5
Very fine sand and decomposed felspar 5 S|
Peroxide of iron, chiefly in the substance
of shell fragments : : . : me)
100 ‘0

In the above-described marls and limestones are found several
curious bodies, but in no great proportion; and, on the whole, they
may be said to be derived from the decay of the fresh-water shells
found in them, and not from the deposition of chalky mud, which
has a totally different character, though the calcareous matter in the
water, from which the shells procured it, may have been derived
from the contiguous chalk. It is worthy of remark, that in these
marls no Diatomacee are found, though they abound i in the clays
associated with some of them; but the examination of tufaceous
travertins has furnished the author with evidence which proves that
contact for a long period with carbonate of lime decomposes end
destroys their siliceous coverings, and therefore they could hardly
be expected to occur in such deposits as those under consideration.

eee’)

ORIGINAL COMMUNICATIONS.

Aupitory Apparatus of the Cutrx Mosquito. By Curts-
TOPHER Jonnston, M.D. Baltimore, United States.

Iris more than presumable that creatures endowed with the
faculty of producing and voluntarily modifying distinct sounds,
should also possess organs for the apprehension and ap-
preciation either of rhythmic or irregular sonorous vibrations.
The insect tribes are precisely in this category ; the apparatus
by which is produced their song, their hum, or their chirp, is
extremely varied, and the sounds which emanate from it offer
a great diversity, even in the larger individuals, or, in other
words, so far as our own auditory organs permit our sense to
follow the rising scale. ‘That these sounds are in some way
perceived by insects themselves we have abundant evidence
in the Cricket (Gryllus), the Grasshopper (Cicada), and espe-
cially in the Bee, which responds to another individual in a
particular note.* Some insects are supposed to be silent;
while the smaller varieties, from the exceeding minuteness
of their parts, give rise to vibrations so rapid as to be in-
appreciable by our ears.

It will readily be admitted that if there bea limit for acute
sounds, corresponding with the smallest number of vibrations
capable of producing an auditory impression, there must also
be a limit to the development of an acoustic apparatus ; and
“we cannot,” as Duges remarks, ‘‘ conceive of a true micro-
scopic ear.” In the Protozoa, therefore, and possibly in the
most diminutive insects, we may abandon the idea of a cen-
tralization of the faculty of perceiving vibrations, and feel
assured that the sense of touch, generally distributed, stands
in the stead of a “sensorial speciality.”

From analogy, pursued downwards, we might expect to
discover the localization of the ‘sensorial speciality,” when
it exists, in the head of insects, or else from analogy, pursued
upwards, might we sometimes look for its seat elsewhere. In
fact we find numerous descriptions of an auditory apparatus
situated in the head of certain species, and in parts connected
with the thorax of other species; but many of the observers
have failed to convince others than themselves; and other
writers have assigned, in some instances, a different function
to the organs spoken of as being concerned in audition.

* Duges. Physiol. Comp.
VOL, III. H

98 DR. JOHNSTON, ON THE AUDITORY APPARATUS

Treviranus* describes the “organ, probably of hearing” of
the Blatta orientalis, as consisting of an oval opening, situated
immediately behind the insertion of the antenne, and covered
with a convex white pellicle, and supposes it possible that the
club-like antenna of the diurnal Lepidoptera contains an
auditory apparatus.

Ramdohrj presumes that the vesicles placed at the root of
the mazille, in bees, have a similar function.

Straus-Durckheim locates the seat of hearing in the foliated
antenne of the May-bug.

Carus} considers it possible “that the membrane, which, in
the Locusta viridissima, unites the antenna with the head, and
offers a tolerably extended surface, is a sort of membrana
tympani, or membrane of a kind of fenestra vestibularis, which
the movements of the antenne@ may relax or render tense.”

De Blainville,§ finding certain apertures like stigmata in
the posterior part of the head of Grasshoppers, supposes that
they lead into a cavity which appears to him an auditory ap-
paratus; and Carus admits the probability of this presumption,
‘as deriving support from the evidence of analogous facts in
the higher classes.” But Duges found the ‘ apertures” to be
simply “ depressions ;’ and he denies positively the existence
of communicating trachee and vesicles, and also of an acces-
sory nervous expansion.

L. W. Clarke|| describes at the base of the antenne of
Carabus nemoralis, an auditory apparatus composed of an
auricle, an internal and external auditory canal, a tympanum,
and a labyrinth.J

Newport** believes that the antenne@ serve as well for touch
as hearing.

Sicbold tt opposes the opinion of Treviranus concerning the
two white convex plates existing at the base of the antenne
of Blatta orientalis, and declares them to be simply rudi-
mentary accessory eyes. The same author gives an account
of an auditory apparatus belonging to the Acridide, consisting
of a tympanum, and a membranous labyrinth supplied with
an auditory nerve proceeding from the third thoracic ganglion.

The Locustide and Achetide have similar organs situated

* Cited in Traité Elem. d’Anat. comp. C.G. Carus. Paris, 1835.

+ Idem. + Idem., doc. cit.

§ Anat. comp. des Animaux artic. Paris, 1828.

|| Magazine of Nat. Hist. 1888.
(in. “i of none of which, according to Siebold, is there the least trace.—

aD

** Transactions of Entom. Society, II.

tt Nouveau Manuel d’Anatomie comparée. Artic. par M. C. Th. y.
Siebold. Paris, 1850,

OF THE CULEX MOSQUITO. 99

in their anterior legs immediately below the coxo-tibial arti-
culation. These organs are composed of a fossa on each
side, or of two, more or less capacious, cavities (auditory
capsules) with orifices opening forwards; and each having on
the inner side an elongated oval tympanum; and the two
tympana are in close contact with a dilatation of the large
tracheal tube of the leg, whose upper extremity is in con-
nexion with an acoustic nerve which derives ics origin from
the first thoracic ganglion. A neighbouring portion of the
tracheal system he supposes to serve the purpose of a Eus-
tachian tube.

And finally, J. Miiller, as quoted by Carus,* regards as
organs of hearing “two depressions or pits, in Gryllus
hieroglyphicus, situated, one on each side, of the metathoraz,
on the dorsal aspect, above the attachment of the last pair of
legs upon and closed by a delicate membrane, behind which
there exists a vesicle, filled with liquid, which receives a nerve
from the third thoracic ganglion.”

While bearing in mind the difference between feeling a
noise and perceiving a sonorous vibration, we may safely assume
with Carus—for a very great number of insects, at least—that
whenever true auditory organs are developed in them, their
seat is to be found in the neighbourhood of the antenna.
That these parts themselves are, in some instances, concerned
in collecting and transmitting sonorous vibrations, we hold as
established by the observations we have made particularly
upon Culex mosquito; while, we believe, as Newport has as-
serted in general terms, that they serve also as tactile organs.

The male mosquito differs considerably, as is well known, from
the female; his body being smaller and of a darker colour, and
his head furnished with antenne and palpi in a state of greater
development. (Plate VI.. fig. 1.) Notwithstanding the fitness
of his organs for predatory purposes he is timid, seldom enter-
ing dwellings or annoying man, but restricts himself to damp
and foul places, especially sinks and privies. The female, on
the other hand, gives greater extension to her flight, and, attack-
ing our race, is the occasion of no inconsiderable disturbance
and vexation during the summer and autumn months.

The head of the male mosquito, about 0°67 mm. wide, is
provided with lunate eyes, between which in front superiorly
are found two pyriform capsules nearly touching each other,
and having implanted into them the very remarkable antennae.

The capsule, measuring about 0-21 mm., is composed of a
horny substance, and is attached posteriorly by its pedicle,
while anteriorly it rests upon a horny ring, united with its

* Loe. ctt,

rey?

100 DR. JOHNSTON, ON THE AUDITORY APPARATUS

fellow by a transverse fenestrated band, and to which it is
joined by a thin elastic membrane. Externally it has a rounded
form, but internally it resembles a certain sort of lamp shade
with a constriction near its middle; and between this inner
cup and outer globe there exists a space, except at the bottom
or proximal end, where both are united.

The antenne are of nearly equal length in the male and the
female.

In the male the antenna is about 1:75 mm. in length, and
consists of fourteen joints, twelve short and nearly equal, and
two long and eqval, terminal ones, the latter measuring
(together) 0-70 mm. Each of the shorter joints has a fene-
strated skeleton with an external investment, and terminates
simply posteriorly, but is encircled anteriorly with about forty
paptlle, upon which are implanted long and stiff hairs, the
proximal sets being about 0°79 mm. and the distal ones
0:70 mm. in length; and it is beset with minute bristles in
front of each whorl.

The two last joints have each a whorl of about twenty short
hairs near the base.

In the female the joints are nearly equal, number but thirteen,
and have each a whorl of about a dozen small hairs around
the base. Here, as well as in the male, the parts of the an-
tenne enjoy a limited motion upon each other, except the
basal joint, which, being fixed, moves with the capsule upon
which it is implanted.

The space between the inner and outer walls of the capsule,
which we term confidently the auditory capsule, is filled with
a fluid of moderate consistency, cpalescent, and containing
minute spherical corpuscles, and which probably bears the
same relation to the nerve as does the lymph in the scale of
the cochlea of higher animals. The nerve ztself, of the antenna,
proceeds from the first or cerebral ganglion, advances towards
the pedicle of the capsule in company with the large trachea
which sends its ramifications throughout the entire apparatus,
and, penetrating the pedicle, its filaments divide into two
portions. ‘The central threads continue forwards into the
antenna and are lost there; the peripheral ones, on the con-
trary, radiate outwards in every direction, enter the capsular
space, and are lodged for more than half their length in saudei
wrought in the inner wall or cup of the capsule.

In the female the disposition of parts is observed to be
nearly the same, excepting that the capsule is smaller, and that
the last distal antennal joint is rudimental.

The proboscis does not differ materially in the two sexes ;
but the palpi, although consisting in both instances of the

OF THE CULEX MOSQUITO. 101

same number of pieces, are very unlike. In the female they
are extremely short, but in the male attain the length of
2°73 mm.; while the proboscis measures but 2°16 mm.
They are curved upwards at the extremity.

If an organ of hearing, similar to that described by Trevir-
anus as belonging to the Blatta orientalis, exist in the head
of the Mosquito, the tympanum must be of exquisitely minute
proportions, because the head, which has a diameter of only
0-67 mm., is almost entirely occupied by the corneal plaques,
the capsules, and the attachments of the neck and of the
buccal apparatus. The membrana tympani must therefore
be so small as to preclude the idea of its being put in vibra-
tion by any sounds other than those infinitely more acute
than are produced by the insect itself, and the use of such an
organ for the purposes of inter-communication must be highly
problematical. But no trace of such a disposition is to be
found in the head, nor very certainly, also, in the body; and
we are obliged to look for some organ which may answer the
requirements of an effective auditory apparatus.

The position of the capsules strikes us as extremely favour-
able for the performance of the function which we assign to
them; besides which there present themselves in the same
light the anatomical arrangement of the capsules, the disposi-
tion and lodgment of the nerves, the fitness of the expanded
whorls for receiving, and of the jointed antenne fixed by the
immovable basal joint for transmitting vibrations created by
sonorous modulations. The intra-capsular fluid is impressed
by the shock, the expanded nerve appreciates the effect of the
sound, and the animal may judge of the intensity, or distance,
of the source of sound, by the quantity of the impression: of
the pitch, or quality, by the consonance of particular whorls
of the stiff hairs, according to their lengths; and of the direc-
tion in which the modulations travel, by the manner in which
they strike upon the antenn@, or may be made to meet either
antenna, in consequence of an opposite movement of that part.

That the male should be endowed with superior acuteness
of the sense of hearing appears from the fact, that he must
seek the female for sexual union either in the dim twilight,
or in the dark night, when nothing save her sharp humming
noise can serve him as a guide. The necessity for an equal
perfection of hearing does not exist in the female; and,
accordingly, we find that the organs of the one attain to a
development which the others never reach. In these views
we believe ourselves to be borne out by direct experiment,
in connexion with which we may allude to the greater diffi-
culty of catching the male Mosquito.

102 DR. WEBER, ON THE NOCTILUCA MILIARIS.

In the course of our observations we have arrived at the
conclusion, that the antenne serve, to a considerable extent,
as organs of touch in the female ; for the palpi are extremely
short, while the antenne are very movable, and nearly equal
the proboscis in length. In the male, however, the length and
perfect development of the palpi would lead us to look for the
seat of the tactile sense elsewhere; and, in fact, we find the
two apical antennal joints to be long, movable, and com-
paratively free from hairs; and the relative motion of the
remaining joints very much more limited.

On the Nocrituca Mitiarts. By Woopuam Wess, M.D.,
Lowestoft.

Mr. Huxtey’s interesting paper in the last number of the
Journal on the structure of the Noctiluca miliaris, led me to
review a few notes I had by me upon the subject, and to
follow up certain points of inquiry which he indicated.

Unfortunately, | am not able to complete the history of
this anomalous creature, though it has been under continuous
examination since last July. It may, however, be worth
while to record the few steps made in advance of the existing
accounts, in order to save other observers some labour, and to
serve as a sequel to Mr. Huxley’s more elaborate communi-
cation,

The extraordinary prevalence of this creature during the
present season seems to have excited general attention, and it
was stated by Mr. Byerly, of Liverpool, at the last meeting of
the British Association, that in consequence of their numbers
the waters acquired a rose colour. This was not the case on
the eastern coast, though the unusually brilliant iridescence
of the water has been the subject of remark. From the month
of July to the beginning of December, there has been no
difficulty in obtaining an uninterrupted supply of specimens,
and during that period the water has shown incessant alter-
nations of luminosity and darkness. These conditions, there-
fore, depend not merely upon the presence or absence of the
animal, but on some peculiar conditions of its organs, or the
media acting upon them.

As a caution to those who may undertake the further exa-
mination, I may state that the buoyancy of the JVoctiluca is
such as to bring it to the surface of tranquil water without
any apparent effort ; and that the best way to effect its capture
is, not as is most frequently done, to use the muslin net, by
which means the greater number of the creatures are lost or

DR. WEBB, ON THE NOCTILUCA MILIARIS. 103

destroyed, but to skim the top, and especially those parts
near the sides of the vessel in which the water has been
standing. If removed in this way and kept by themselves in
a test-tube, they may be preserved for two or three weeks
without a fresh supply of water. Even at the end of that
time, if they die, it does not appear to be from having reached
the natural term of their existence, but as the result of some
accidental cause ; they will not, however, bear carriage to any
great distance in closed vessels.

The following paragraphs refer to various matters, accord-
ing to the order in which they occur in Mr. Huxley’s paper.

The groove or depression on the body is divided into two
portions by a fold of the external membrane stretching across
between the protuberant and rounded masses which form its
boundaries. It ends posteriorly in an acute angle, outlined
by the bifurcation of a more superficial marking or channel.
The stem of this forked structure is of a rigid horny nature,
and is connected at the point of division with a reduplication
of the internal membrane, or a prolongation of the central
visceral mass. I have not been able at any time to detect an
aperture at this spot, but there is some reason to believe there
may be one. When the ruptured integument collapses, this
straight spine may still be seen retaining its rigidity, and is
the centre about which the folds arrange themselves.

The investing membrane distinctly consists of two layers.
The external one is minutely reticulated, and has somewhat
the appearance of pavement epithelium ona small scale. The
interspaces contain granular matter. With this exception it
is perfectly srnooth, and I can find no trace of cilia. Ilumi-
nated by a parabolic condenser, the whole surface is seen
studded with brilliant glittering points, apparently at the
junction of the reticulations of the internal fibres with the
integument. I have never been able to develope luminosity
under the microscope.

The internal layer is at all points in union with the whole
system of reticulations spreading from the central organs.
This was made manifest by the action of indigo. None of
the colouring matter entered the body, but death ensued in
about an hour’s time. frregular jerking movements took
place, the oral aperture and parts about it became distorted,
though the motions of the ci/iwm and tentacle still continued.
‘The internal fibrous reticulations gradually contracted, drawing
the ‘‘ vacuoles” together, and with them the inner membrane.
This was detached without rupture, but after a time fell into
folds, which so included the other structures as to have the
look of a wrinkled tube with a series of pouches ending in a

104 DR. WEBB, ON THE NOCTILUCA MILIARIS.

arger membranous sac. The external layer distended by
degrees till it suddenly burst. I should mention that a new
supply of water had been given before most of these changes
happened. I have also been successful in separating the two
layers mechanically, by means of pressure slowly and steadily
applied to the animal under the screw compressor. The whole
internal network of fibrous tissue, with the manner in which
it invests the so-called “ vacuoles,” is most beautifully demon-
strated by the effect of iodine. The creature dies suddenly
without collapsing. ‘The progress of the fluid can be traced
along the fibres into the minutest meshes; and there remains
for a long time a transparent ball, traversed in every direction
by the brown fibres, beaded with the vacuoles and granules,
and having every reticulation on the surface sharply defined.

Iam inclined to regard the tentacle as tubular, with an
orifice on the inner side at its base. At any rate, I have seen
the colour, when iodine has been used, proceed slowly towards
the distal extremity ; and under the influence of indigo poi-
soning, the granular matter of which the striation consists,
has been disarranged, scattered up and down the interior of
the organ, and in the end has aggregated together in small
globules without much impairing the power of motion. I
recognize no trace of striation in the external membrane ; and
when seen in the normal condition by transmitted light, there
is always a clear substance surrounding the dark centre. This
gives the i impression of being made up of a series of discs or
rings. The tentacle is extr emely brittle, and breaks with a short
On STE, I have never perceived any tendency to restoration
of the lost part, nor any independent movement in the de-
tached fragment. The stump continues active, and readily
comes off at the base. The point is a little flattened. When
the animal is killed in such a manner that this organ has free
play, it always shows a disposition to coil up spirally. The
cilium may be found in every instance in which it is looked
for with a quarter-inch glass,* or even with the half-inch, pro-
vided the creature is left at perfect liberty, and is made to
move, if not in the right position. It often remains at rest
for some time, and then from above looks like a small bright
spot at the base of the “tooth;” or it may occasionally be
seen extended over the S-shaped ridge, or even the base of
the tentacle. I have many times detected it in motion from
behind through the intervening substance of the body; and
have noticed it vibrating vigorously long after rupture of the
integument and partial discharge of the contents. A Chara

* T use a quarter-inch glass of Pillischer’s, or a 1-5th of Smith and
Beck’s make.

DR. WEBB, ON THE NOCTILUCA MILIARIS. 105

trough or shallow concave cell is most convenient for obser-
vations on this part, as the animal swims close to the under
surface of the thin glass, and may be made to turn in any
direction.

The ridge and tooth can scarcely be overlooked. This
ridge is of fibrous structure, and may sometimes be observed
in regular contractile action, Corresponding with these con-
tractions, I have witnessed a to-and-fro motion of the tooth,
as though working on an axis, in a direction towards the base
of the tentacle. A good illustration of this performance is
given by bending the fore and middle fingers and flexing
them on the palm of the hand. The tooth when seen in profile
has the appearance of a conical papilla (Plate Vij fig:*6);
or with a slight change in the point of view, of a hooked
process terminating in a sharp nib (figs. 8, 9), It readily
yields to pressure, Sandal have seen it become shrivelled up
from the use of astringents, before motion ceased in the cilium
and tentacle.

The ‘ vacuoles” are alimentary sacs. When empty, they
are usually contracted and grouped near the membranous tube
which leads from the oral aperture, a few only being scattered
among the internal reticulations, ‘Their situation is constantly
changing, sometimes with a steady advance, at others by jerks ;
while the fibrous meshes with which they are connected
undergo a relative alteration in shape. Gentle pressure will
occasionally expel them through the oral or anal aperture ;
but I have seen them spontaneously ejected without rupture,
and float away from the body. In one instance where this
occurred, and where the contents consisted of granular matter,
fragments of Diatomacez, and particles of sand, the sac re-
mained entire for some time. When it burst, the membrane
doubled up, the contents escaped, and the bits of silica were
characteristically shown with the polariscope. I have never
known these gastric pouches, or alimentary substances to be
voided by any other outlet than those connected with the
central depression.

The position of the second aperture, or anus, communica-
ting with the gastric pouch, appears to me to be at the pos-
terior end of this depression, on the side opposite to the
tooth, and somewhat further back (fig. 7).

The mode of reproduction is at present far from being
satisfactorily made out. I have never met with a double in-
dividual, but on one occasion witnessed the process of division,
without, however, noting any proof of its connection with
that of fissiparous multiplication. Contractions of the in-
tegument took place in such a way as to cut off a globular

106 DR. REDFERN, ON THE TORBANEHILL

mass from the body, about one-fourth of the whole. The two
portions afterwards retained their form with a puckered mark
at the point of separation. The nucleus was not involved in
this operation, which occupied about two hours.

It is also a matter of every-day observation, that when the
body has been torn and nearly all the contents have been lost,
the animal continues to live in a deformed state, if the nucleus
and central parts are left together. They acquire a new in-
vestment, or a portion of the original integument gathers up
round them, while the ragged shreds are cast off.

When several of these creatures have been kept for some
time in still water, it is not unusual to find two of them in
apposition ; but I have never discovered any indications of
conjunction, and look upon the condition as one of mere
adhesion. It may, however, have given rise to the mention
of double individuals, as the adhesion is tolerably firm. It
may easily be broken up without injury to either animal.

The nucleus may be demonstrated as a nucleated vesicle,
sometimes solitary, more frequently with several similar, but
smaller nucleated vesicles grouped around it. By careful
manipulation it may be removed from the other structures.
As it floats about, the true form is displayed. Seen in one
position, you have a view of a round vesicle with a smaller
vesicle attached to it by a sort of hour-glass contraction; in
another, of a round vesicle with a central spot, a nucleated
cell.

I have found the nucleus enclosed in a second membranous
envelope, with a granular yelk-like fluid, which could be seen
pouring out when the membrane gave way (fig. 10).

Beyond this point I have not been able to trace the nucleus.

On the Nature of the TorBaNEnILL and other Varieties of
Coat. By Peter Redfern, M.D., Lond., Lecturer on An-
atomy and Physiology, and on Histology, in the University
of Aberdeen.

(Read at the Meeting of the British Association for the Advancement
of Science at Liverpool, 1854.)

Tue substances to which I intend to allude in the following
paper, under the name of coal, are such as, known commonly as
coal, consist of compressed and chemically altered vegetable
matter, associated with more or less of earthy substances, and
capable of being used as fuel.

Though I shall confine myself chiefly to the structural cha-
racters which coals present, I shall refer briefly to their chief

AND OTHER VARIETIES OF COAL. 107

geological and chemical relations ; for it is my firm conviction,
that if the geological, chemical, and microscopical characters
of such substances do not mutually illustrate and confirm
each other, the truth has not been arrived at.

It is my chief object to bring forward a number of facts,
which I have arrived at after a prolonged investigation, and
to detail the method which I have followed in such a way as
to enable every reader to repeat my observations, and either
to confirm or disprove them.

I have taken the greatest care to obtain authentic speci-
mens, if possible, from different sources, and I have examined
none of the perfect authenticity of which I had not the most
certain evidence. I have carefully examined complete sec-
tions of the beds of coal of most importance in the inquiry.
I have broken up these masses, and examined the beds with
the naked eye from top to bottom. In the case of the Tor-
banehill coal I have made thin sections horizontally, and in
two directions vertically, at distances of a few inches through
the thickness of the bed, to determine the structure of the
whole; and I have likewise examined the coals when reduced
to powder and coke. I have examined upwards of 200 sec-
tions, and other microscopical preparations of different coals,
of which 180 were prepared by my own hand from speci-
mens, the perfect authenticity of which I can easily prove.
In the whole examination I have endeavoured to make out
every fact as it presented itself, and to adopt no explanation
not consistent with the whole, and with the evidence derived
from every means of observation. Yet I have no wish that
anything which I may advance should be taken for granted.
I am prepared to prove every statement of facts by the pre-
parations on which my observations were made.

The Torbanehill coal, which has recently excited so much
attention, owing to the well-known jury trial, Gillespie v.
Russel, is found in the coal-measures of the lands of Tor-
banehill, in the parish of Bathgate, county Linlithgow. It
forms a bed, varying in thickness from 1 foot 4 inches to
1 foot 1l inches, becoming darker in colour, coarser in tex-
ture, and less valuable as a gas coal, at Bathvale, on the west
of the lands of Boghead; and very much coarser, and less
valuable still, at Barbachlaw, about half a mile to the north-
west of Boghead, where the seam is worked by the Monk-
land’s [ron Company.

The position of the bed does not differ from that of a bed
of coal. It has a thin layer of cement-stone immediately
above it, varying in thickness from half an inch to two inches.

108 DR. REDFERN, ON THE TORBANEHILL

Above that is a bed of shale, varying in thickness up to
four feet. Immediately below the bed is a stratum of
fire-clay, with occasional ironstone-balls, about two inches
thick, and very full of the impressions of plants. Under that
isa layer of good bright-looking coal of six inches in thick-
ness. Occasionally a thin layer of common coal runs through
the cannel, and is variable in thickness. It appears, there-
fore, that the bed is in a similar geological position to that of
other cannel coals.

In working the coal, it is got in rhomboidal blocks, ex-
tending through the whole thickness of the seam, and mea-
suring from six to sixteen inches in breadth, and from five to
fifteen in depth (back). The fracture perpendicular to the
plane of stratification is conchoidal, that parallel to the same
plane is slaty. The colour is of a light brown, and the streak
yellow and dull in the upper part of the seam; in the lower
part the colour is, in many specimens, as dark and lustrous as
that of many other cannels, and the streak varies in a like
proportion.

When viewed chemically (I now quote from the evidence
of Dr. George Wilson, one of the pursuer’s witnesses at the
late jury trial), ‘‘ There is no ingredient in common coal that
is not at all present in the Torbane mineral. There is no
ingredient in Torbane mineral that is entirely absent from all
known coals,”

But there are some chemical peculiarities. .The quantity
of earthy matter is large, 18 per cent. ; but many well-known
coals contain a still larger quantity. The fixed carbon is
small in quantity, but analyses of other coals have shown less ;
and the total carbon is quite equal] to that in other cannel
coals—654 per cent. (Hoffman and Stenhouse). ‘The hydro-
gen is in very large quantity (7} to 9 per cent.), but even in
this particular the Methill coal approaches very closely ; for
Professor Anderson found 7°54 per cent. in it.

The following tables, copied from a paper by my esteemed
friend Dr. Fyfe, published by the Royal Scottish Society of
Arts, will be found of great value in comparing the Torbane-
hill with other coals. To the whole of that paper I may refer
as a statement of a mass of facts, unquestionably proving that
the Torbanehill mineral is similar in every chemical relation
to other coals.

On this table Dr. Fyfe remarks: “That the proportion of
volatile matter of the coals varies from about 37 to nearly 67
per cent. ; of course the coke varies from about 33 to 63. The
proportion of fixed carbon and of ash in the coke also varies ;

AND OTHER VARIETIES OF COAL. 109

the former being from about 18 to 52, the ash from 3°6 to

28°5.”

TaBLE of the Proportions of Volatile Matter, of Coke, of Fixed Carbon,
and of Ash, in 100 parts of different Coals, and in the Torbane Mineral.

coins. ol In ower of | Gore! In Geis of

c. cannel. Specific ios ae _ é

Gravity. | ;
h. household. : [glatile Coke. |Carbon.| Ash. |Carbon.| Ash.
atter,
——— | | | | |
Wigan, Ince Hall. c. | 1255 | 37:6 | 62°4 | 56°0| 6°4 | 89-7 | 10°3
es - Cuil) oc | BF27 | GBP SqebOebe elealeSk- Oy | 1940
Torbane household . 3823 || Glitz a2es 9°2 | 85°0 | 15-0
Kinneil. c, a 44°4 | 55°6 | 44:4 | 11°2 | 80°0 | 20°0
Donibristle . c. | 1237 | 46°5 | 53°5 | 49°2 | 4°3 | 92:0} 8:0
Capledrae (2nd) . c, | 1310 | 47°2 | 52°8 | 24-3 | 28°5 | 46-0 | 54-0
Knightswood . . c.| «- | 47°5 | 52°5 | 48°5 | 4:0 | 92-4] 7°6
Balbandiel*)j.) «he ° 43°6 | 56°4 | 29°8 | 26°6 | 52°8 | 47°2
Weochgelliess\)). sc; ae 50°4 | 49°6 | 36°2 | 13:4 | 73°0 | 27-0
: Disco Island h. | 1884 | 50°6 | 49°4 | 839-6 9°8 | 80°0 | 20°0
Monkland. . Ge F 54°22) | 45°8 | 39°5 6°3 | 86°2 | 138°8
Lesmahago . . ©. 2) 5724 | 42°6)) 89°0 |) 3°67 915 |) Sh
on attack Pes . Sed eal qe | Shes 6°4 | 84°6 | 15°4
Witedvitl Go ae ch Oe oe 59 0) || 41-04) 185) 22°5 | 45:0) |) 55-0
Capledrae (Ist) . c. | 1238 | 59°1 | 40°9 | 38-2] 7:7 | 18°8 | 81-2
Wemyss eek Ce 66°6 | 383°4 | 21°9 | 11°5 |] 65°5 | 34°5
|
Torbane re 66°9 | 33°1 | 15-6 | 17°5 | 471 | 52-9
D . e 1 68eL | sl ON) 45) | V7 4) 45-4 | 54°6
on e e 68°4 |} 31°6 SG e2acOe ls 22 teas:
bk ie 69°0 | 31:0 | 9-3 | 21°7 | 30°0 | 70-0
a c 69°8 | 30°2 | 13-1 | 17*1 | 43-3 | 56°7
a5 ° c 69°8 | 30°2 G66) 2322) 629285) 70s2
a sincakes aC 70°1 | 29-1 | 16°3 | 12°8 | 56°0 | 44°0
|

» average. . | 1199 | 68-8 | 31°2 | 11°9 | 18-3 | 38°4 | 61°6
‘reenehorbane »* i)" °.- 68°8 | 31°2 | 10°8 | 26°4 | 34°6 | 65°4

*‘ The average per-centage of these ingredients in Torbane
mineral is 69 of volatile matter, 31 of coke, 12 of fixed car-
bon, and 18 of ash. It does not, therefore, differ from coals
excepting in two particulars: viz., that it yields more gaseous
products and less fixed carbon. But even in these the differ-
ence is very trifling; being only about 2-4 per cent. more
than that of the former from Wemyss’ coal, and 8°5 less of
the latter than from Methill coal : indeed, some of the samples
of Torbane contain only 2 per cent. less. The per-centage of
ash in some of the samples is less than in several of the coals ;
and the average quantity is not so great as that of Methill
and Capledrae.”

110 DR. REDFERN, ON THE TORBANEHILL

TABLE showing the average proportion of the different (ultimate) ingre-
dients of Coal and of Torbane Mineral.

Coats. Carbon. |Hydrogen. | Oxygen. | Nitrogen. | Sulphur. | Ash.
Ete repel
COUCH ee we «| COS ool 8°45 1°32 1°25 2°16
Welsh: = « | eked 5°01 7°36 0°83 1°66 3°8
Neweastle. . «- | 84°3 5°86 6°37 1°28 0°68 1°51
Derbyshire . . | 79°65 4°96 10:17 1°48 1:07 2°69
ancashire; ~< .. | 76°53 | 405mm e129 1:2] | Ado
Foreien’ <2. || 65°82 || S56 OW | sos} 1-05 | 21%
Capledrae.. . « | 56277 | 26°79 8°79 V9 0°35 | 25°4
Torbane . . . | 60°25 8°86 3°62 1°53 | O18 | 25-6

Dr. Fyfe says, “‘ The Torbane mineral, in a chemical point
of view, resembles coal. It has in it all the component parts
of coal, and in nearly the same proportions as in some of
them. It does not contain anything that is not found in coals.
It yields the same products by distillation, at different tem-
peratures ; such as gas for illumination, tar, and ammoniacal
liquor, benzole, naphtha, naphthaline, pitch oil, paraffine oil,
and paraffine. I have shown also that it differs materially
from asphalt, and from shales, and bituminous shales, in con-
taining almost no bitumen.”

So chemistry points out that the Torbanehill coal is made
up of the same substances as compose other coals, and that
such proportions of these individual substances as exist in it
are also found in other coals. Further, its chemical compo-
sition points clearly to its formation from the organic king-
dom of nature.

When a thin piece of this coal is lighted at a flame it
burns like a candle, hence such coals have been called candle
or cannel coals; when a piece is thrown on the fire it crackles
in splitting to pieces, and for that reason it and such like
coals are called parrot coals.

Structure of the blocks in which the coal is found naturally
and solid. 'They are very tough, elastic, and difficult to break,
unless they are struck on their sides with a sharp-edged ham-
mer, or with a knife and hammer; the blocks then split into
thin layers with great ease. I have split 16-inch blocks in
this way into 16 layers of one inch in thickness, without
breaking more than one of them. Yet not one entire piece
can be split off in the vertical direction by any means what-
ever. If the hammer be applied perpendicularly to the sur-
face of the bed, the fracture produced is conchoidal.

One great fact has thus been arrived at: the whole bed of
Torbanehill coal is laminated. I think the importance of this
fact has not yet been thoroughly understood.

= oe

AND OTHER VARIETIES OF COAL. 111

In every part of the coal very evident fossil plants are
found. Some are in the shape of large trunks of trees, fluted
vertically on the surface, and one to two feet in diameter.
The most numerous are Stigmaria, of various sizes, flattened,
and sending off abundant rootlets into the mass. I do not
believe that a single fractured surface can be shown which
does not present portions of fossil plants, and these are in
every respect similar to those found in other cvals, but far
more numerous than they.

Every fractured surface likewise shows a number of an-
gular, flattened facets, on different planes from that of the
general surface of the fracture. ‘These occur everywhere in
the bed. Nota cubic inch of the coal can be got without
them ; they, too, are impressions or portions of fossil plants,
When examined with a pocket-lens, or a low power of the
microscope, these surfaces, and the larger surfaces of the more
obvious fossils, present similar appearances, and show, over
spaces not unfrequently of many inches in extent, the scalari-
form tissue so abundant in ferns, or some closely allied vege-
table tissue. ‘The vessels of this tissue present themselves
on their sides, and in various oblique and transverse sections
in the different parts.

If it be borne in mind that a very large portion of the whole
bed of coal is made up of such easily recognisable vegetable
structures, and that 654 per cent. of the mass is carbon, I think
but little difficulty will be experienced in arriving at the con-
clusion that it owes its origin almost entirely to the vegetable
kingdom.

Before leaving these fossils, it is to be carefully noticed
that it is only when the fracture has exposed them in a par-
ticular way that they are thus distinguished from the mass in
which they are imbedded. [For the most part, the appear-
ances they present on any but their natural surfaces are exactly
those presented by the mass. When a fossil stem is carefully
separated from the coal, and its surfaces are recognised as
natural faces presented by the plant, one is surprised to find
that the structure of thin sections made through it does not
differ from that of thin sections of the whole bed, except
where scalariform vessels appear. Now, there is no ground
for the belief that there ever was a plant containing scalari-
form vessels, of which the greater part was not composed of
a softer and cellular mass; and there is just as little reason
for supposing that, where the shape of a plant and its scalari-
form vessels have been so perfectly preserved, there would be
no trace of its other structures. So, when it is shown that
there is a very remarkable arrangement of the parts of these

FD DR. REDFERN, ON THE TORBANEHILL

fossils, and that the same arrangement, in all its essential fea-
tures, exists in all of them and in the substance in which they
are imbedded, I think that good, if not altogether conclu-
sive, evidence is offered, that the bed of coal which contains
fossil vegetables, and has everywhere the same essential cha-
racters of structure and chemical composition as those fossils,
is itself a bed of vegetable matter.

Let us now pass from these general observations to more
special ones, less easily made and understood. Cut a small
block of coal from the Torbanehill bed, say of one inch long,
two-thirds of an inch wide, and half an inch thick, so that its
upper and lower surfaces shall be exactly parallel to the sur-
faces of the whole seam ; polish its faces, and having coated
them with varnish, or covered them in turn with a drop of oil,
examine them with magnifying powers from 5 to 100 diameters
as opaque objects. The upper and lower surfaces of such a
block are alike, and the sides and ends are alike, but widely
different in appearance from the upper and lower surfaces.

The top and bottom of the block are studded with more or
less rounded yellow spots, closely set in a darker mass; the
sides and ends present a number of elongated yellow spots
in a darker mass. Such appearances are presented by the
surfaces of all such blocks, from whatever parts of the bed of
coal they may have been taken ; but they are least obvious in
the upper part of the seam, and are more easily recognised
the lower the part examined. These appearances I believe
to be produced by rounded yellow masses, flattened above and
below.

There are also to be seen on all such blocks irregularly
elongated and angular black patches, and branching black
lines, which run in various directions on the upper and lower
surfaces, but for the most part in the direction iu which the
coal splits on the sides and ends. Near the top of the seam,
crystals are seen scattered on all the surfaces of the blocks.

The appearances presented by the surfaces of small blocks,
I think, have been mistaken in the case of other coals for
evidence of their consisting of woody tissue, whereas they are
merely the result of the laminar aggregation of the structures
of which beds of coal are formed.

Let us for a moment examine the differences presented by
a block of wood and one of coal. If we take such a block as
that of which I have spoken from the trunk of a tree, so that
its upper surface would look towards the branches, and the
lower towards the root, these surfaces will present us with a
number of rounded openings and rings, which are the cut ex-
tremities of the vertical fibres and vessels of which the wood

AND OTHER VARIETIES OF COAL. 113

is made up; whilst the sides and ends of the block will be
striated vertically, because they show the sides of the fibres
and vessels, which have been separated from each other in
their course.

The block of coal presents rounded yellow spots above and
below, and horizontally striated sides and ends. Now, there
is this wide difference between the wood and coal—that wood
Is composed of a multitude of fibres and vessels, arranged
vertically i in a tree, and therefore cut across by a horizontal
section, and separated from each other so as to produce a ver-
tical striation on every vertical section, make it where you
may. Coal, on the other hand, consists of a multitude of
thin laminee, applied upon een other like the leaves of a
book. These laminz are made up of rounded yellow bodies,
flattened above and below, imbedded in a darker mass, and so
on every horizontal section these bodies are separated as one
would lift off the coins of a pile from each other; whilst a
vertical section passes through them as such a section would
through the pile of coin.

There is, therefore, as much resemblance between a block
of coal and one of wood as there is between a substance com-
posed of a series of lamina, and another made up of a number
of fibres closely packed together.

We now turn to the appearances of thin sections of the Tor-
banehill coal, when examined by high powers of the micro-
scope.

I think it will be obvious, from what has been said, that
the nature of any substance which can be examined by sec-
tions may be made out if such sections are made horizontally
at different depths, and vertically in several directions, so that
the planes of these vertical sections are at various angles to
each other. Or, if we cut sections from the top or bottom,
and from the side and end of such small blocks as those be-
fore named, these will enable us to judge of the nature of the
structures of which the mass is composed.

Pieces of coal may be split horizontally from a block with a
knife and hammer with great ease for making thin horizontal
sections ; but, for vertical sections, a saw or the diamond-
wheel of the lapidary must be made use of. All sections of
the Torbanehill cannel may be ground sufficiently thin by the
hand without being cemented to a slip of glass in the ordinary
way. This plan is far more satisfactory in its results than
any other I have tried, and is much less likely to lead to error,
from destruction of tissue or obliteration of it by the materials
used in making the sections. I have 26 sections, horizontal
and vertical, which I prepared in this way from the same

VOL, III. t

114 DR. REDFERN, ON THE TORBANEHILL

block of coal. To ensure accuracy, I made sections in three
places, at different depths, in half an inch of cement-stone at
the top ; and others in the coal, at distances of 2, 4, 6, 10, and
16 inches from the top of the seam. The results were pre-
cisely similar to those which I obtained from sections prepared
from numerous other blocks of the coal obtained from a great
variety of sources. At each part of a bed of coal examined
I have made at least three thin sections, and distinguished
these from each other by the letters H. S., for horizontal sec-
tions; V.S. a., for vertical sections taken from the side of a
small block; and V. 8S. b., for vertical sections cut from the
ends of such blocks. Having bestowed the greatest care in
the investigation, from beginning to end, I feel assured that
other observers will corroborate my facts and the correctness
of my drawings, from which the accompanying plates have
been executed, however different their conclusions may be
from my own.

Horizontal sections taken from all parts of the Torbanehill
coal, except about the upper two inches, show :—

1st. A number of irregularly rounded spots of a lemon-
yellow colour, varying in diameter from about 1-250th to
1-800th of an inch, and bounded by dark-brown matter, which
separates them from each other (Plate VII., fig. 3), or from,
2nd, smaller yellow patches, of a distinctly angular and poly-
gonal shape, having a very uniform diameter of 1-1500th of
an inch, and a dark-brown outline, which in many places is
distinctly double.

Vertical sections show these yellow spots elongated, mea-
suring about 1-300th to 1-1200th ef an inch horizontally, or
in the direction of the lamine of bedding, and from 1-500th
to 1-1900th of an inch perpendicularly to these lamine and
the whole bed (Plate VII., fig. 4). In whatever direction a ver-
tical section is made, the appearances which it presents are
the same. In every one there is a general horizontal striation ;
z. e., having its striae parallel to the lamin of bedding. In
horizontal sections there is no striation whatever.

Here are two points of such primary importance in the in-
quiry into the real nature of the Torbanehill and other coals,
that I cannot do them sufficient justice without a slight
digression from the preceding account of the appearances of
sections.

I have before stated that a small block of coal with six
surfaces presents two appearances when examined as an
opaque object: one on its upper and lower surfaces, and the
other on its sides and ends. One appearance is that of a
number of rounded yellow spots in a black mass; the other,

AND OTHER VARIETIES OF COAL. PES

that of a number of elongated yellow spots, so close together
in the same mass that the black matter between them forms
black striae parallel to the lamina of bedding. I have now
shown that thin horizontal and vertical sections of the coal
differ in the same manner and degree: horizontal sections
showing rounded yellow spots with dark-brown boundaries ;
and vertical sections, elongated yellow spots with dark-brown
boundaries, like dark striz running in the direction of the
laminz of bedding of the coal.

I stated at the outset that the coal will split with great ease
horizontally, but in no other direction. I would now point to
such vertical sections of coals as have been prepared without
having been cemented to the glass slide, for the most positive
proof that all such sections break up with great ease in the
direction of the striz parallel to the lamine of bedding, whilst
such a tendency to split is never observed in horizontal
sections.

I explain the tendency to split, which exists in all vertical
sections but never in horizontal ones, by the wide differences
in the microscopical characters of such sections ; and I think
it need scarcely be observed, that the characters presented by
the whole bed of coal, by small blocks when examined by low
powers of the microscope as opaque objects, and by thin
sections examined by high powers, mutually illustrate and
explain each other.

The only professedly complete account of the structure of
the Torbanehill as compared with other coals was given about
nine or ten months ago, in a paper read before the Micro-
scopical Society of London, and published in the last volume
of its Transactions. This paper, it is stated, was founded on
an examination of sections of most of the well-known varieties
of British coal, and supported by drawings and an extensive
series of preparations. Its conclusions, moreover, appear to
have received the assent of the Society; for the President
stated in his published address that ‘the paper clearly de-
monstrates the presence, not merely of the remains of plants,
but of a peculiar woody structure in every description of coal,
and the absence of this peculiar structure in the mineral in
question.”

There appear to be two very important statements in that
paper, on which its conclusions are founded :—Ist. That in
the Torbanehill coal there is ‘no difference in structure
whichever way the section is made ;” and, 2nd, that a cubical
fragment of coal ‘on four of its six sides, in certain lights,
will exhibit a fibrous appearance, like a longitudinal section
of wood ;” again, that ‘‘ transverse and longitudinal sections”

12

116 DR. REDFERN, ON THE TORBANEHILL

of coal “are totally different, but both agreeing with cor-
responding sections of wood.”

First, the Torbanehill coal shows “no difference in struc-
ture whichever way the section is made.” My conclusion is
exactly the reverse :—That there is always a remarkable dif-
ference in horizontal and vertical sections of Torbanehill coal ;
and to this I add, that that difference is of the same kind as
the difference which exists between horizontal and. vertical
sections of other coals.

In evidence of the correctness of my observation I refer,
Ist, to the illustrations accompanying this paper; 2nd, to
confirmatory photographic representations of different sections
which I exhibited at the last meeting of the British Associa-
tion ; 3rd, to all horizontal and vertical sections prepared in
the way I have directed, as they all show a very marked
difference even to the naked eye; and, 4thly, to the fact that
the Torbanehill coal will only split in one direction; in it-
self furnishing undeniable evidence of there being some
difference in the arrangement of the structure in different
directions.

Second, a cubical fragment of coal “ on four of its six sides,
in certain lights, will exhibit a fibrous appearance, like a
longitudinal section of wood ;” and “ transverse and longitu-
dinal sections” of coal “ are totally different, but both agreeing
with corresponding sections of wood,” My conclusion is, that
a cubical fragment of coal on four of its six sides exhibits a
striated appearance altogether unlike that presented by a
cubical fragment of wood, and produced by the laminar
aggregation of the structures of the coal. To support my
conclusion, I simply draw attention to the tact, that if I cut
a piece of wood across the direction of the striz on one of its
surfaces I see a number of rings, which are the cut ends of
the woody fibres and vessels; but if I cut a piece of coal in
the same way, I only find other stria produced by its laminae,
as if I were to cut in various directions across the leaves of a
book. Again, it is stated “that transverse and longitudinal
sections’ of coal ‘are totally different, but both agreeing
with corresponding sections of wood.” I conclude that,
though horizontal and vertical sections of coal differ, both are
also entirely and essentially different from corresponding sec-
tions of wood; for, whilst all vertical sections of coal present
the same horizontally-striated appearance, corresponding sec-
tions of wood present striz arranged vertically. If we cut
across the stria of wood we see the ends of its fibres and
vessels ; but when sections are made across the direction of
the striz of coal, other strize appear; for the simple reason

AND OTHER VARIETIES OF COAL. Lu

that the striz of wood are produced by fibres and vessels, but
the striz of coal are due to its formation of lamine.

We now return to our examination of the appearances of
thin sections of Torbanehill coal :—

Many of the larger yellow spots of horizontal sections
(Plate VII, fig. 1) are lobed, as if compounded of three or more
smaller spots joined together. In the greater number of these,
more or less distinct double lines, which radiate from the
centre of the spots, divide them into a number of polygonal
spaces, more highly coloured than the spaces between the
double lines, and often presenting at some part a still darker
spot in each. This delicate division of the yellow matter
into polygonal masses is most obvious when preparations are
preserved in Canada balsam, and almost entirely disappears
when sections are preserved and examined in fluid. A similar
radiate striation exists in the corresponding reddish-yellow
bodies of the Wemyss coal (Plate VIL, figs. 5 and 6). But it
happens very commonly that the dark-brown matter of the
boundary of these spaces stretches into them for some distance
in lines at times reaching to their centres, where there are
other dark-brown lines arranged in a radiate (often a tri-
radiate) manner. These lines are quite permanent in whatever
medium the sections may be examined.

The action of heat offers great assistance in the determina-
tion of the nature of the yellow spots. It dissipates the whole
of the yellow colour, and leaves angular and polygonal open-
ings in the thin section, bounded by the dark-brown matter,
which it has slightly blackened (Plate IX., fig. 2). It can now
be determined, even upon a single section, that the boundaries
of the yellow matter form definite walls for all the smaller
spaces, for where the section has passed directly through the
wall, this is shown by a broad, sharp, black line; but where
it has cut the yellow mass near its upper or lower wall, there
is a shading from the edge of the spot towards its centre, as
would be the case if the boundary were formed of vegetable
membrane. But further, in such yellow spots as present no
very clear indication of the existence of membranous septa in
their interior, heat often renders the existence of such septa
as obvious as in other parts. A yellow spot is shown in
fig. 2, from half of which the yellow matter has been entirely
driven off, whilst it remains in the other half. In the half
least acted on by the heat, this agent has blackened septa
which before were scarcely visible ; and, in the other half, such
septa are seen to form the boundaries of spaces of a regularly
angular and polygonal shape, and of the same size as those
which constitute the smaller yellow patches of fig. 3, Plate VIT.

118 DR. REDFERN, ON THE TORBANEHILL

The appearance of the sections to which heat has been
applied is quite sufficient to determine the fact that the gas-
giving power of this coal depends upon the yellow matter, the
ainount of which is indicated generally by the light colour of
the coal. No coal is so yellow as this in thin sections, and
there is none which approaches it in gas-giving power.
Torbanehill coal produces 15,000 cubic feet of gas per ton,
and the best of the other known coals will not yield more than
12,000 cubic feet per ton. It may be suggested, that the dark
boundaries of the spaces from which the yellow matter has
been driven off by heat consist of earthy matter; but I think
no one would arrive at that conclusion who had tested their
strength by pressure and friction between two glasses when
the preparation was immersed in viscid balsam. I do not
doubt that the earthy matter has been leit by the heat with
the free carbon of the texture, and I think the absence of all
crystalline or other obvious earthy particles in the middle
and lower portions of the seam sufficient proof that the
18 per cent. of earthy matter which chemistry proves to be
present in the coal has got there in a state of solution, or of
fine molecular subdivision,

Now, what conclusions can be drawn from these facts as to
the nature of the yellow spots? They are more or less circular,
flattened, solid bodies, containing a large portion of the gas-
giving substance of the coal, and bounded by vegetable fibres
and membranes often in a fragmentary state. Heat drives off
their yellow matter in the shape of gas, and shows in their
very substance polygonal cavities with definite walls, where,
without heat, such cavities and septa could not have been
supposed to exist. I cannot explain the nature of these bodies
otherwise than by supposing them to have had their origin in
a mass of vegetable cells and tissues which have been disin-
tegrated and otherwise changed by maceration, pressure, and
chemical action, and subsequently solidified. | Moreover,
exactly similar bodies make up a large portion of cannel
coals generally. I would especially refer to the Wemyss,
Methill, Capledrae, and Rochsoles coals. Of these the Wemyss
coal is especially remarkable in showing the radiate striation
of the yellow masses of the Torbanehill coal ; and, if I am
not greatly mistaken, it demonstrates a clear relation between
the yellow bodies just named, and the dark rings of horizontal
sections of Lesmahago, Kinneil, Lochgelly, Wigan, and other
cannels, which have been described as transverse sections of
vessels or fibres.

But there are smaller and more regular yellow spaces,
having tar more definite walls, sometimes double (Plate VIL,

AND OTHER VARIETIES OF COAL. 119

fig. 3). These are found in every part of the coal, in greater
or less number, and they occur also in patches in the cement-
stone covering it. They are almost exactly of the same size
as the polygonal spaces shown in Plate LX, fig. 2, to illustrate
the action of heat. I can conceive no other interpretation of
these spaces than that they are actual vegetable cells, much
less changed than those before named.

drd. The dark-brown material between the yellow masses
is very scanty and granular where these masses almost merge
into each other; elsewhere it is in considerable quantity, and
is studded at slight intervals with patches of a yellow, red,
brown, or almost black colour, in shape elongated, angular,
rounded, bifurcate, and bent or even coiled. ‘These make up
a large portion of the whole substance between the yellow
masses,

In yertical sections, this dark-brown matter forms lines
which traverse the section in the direction of the laminz of
bedding, and are obviously the same lines as give the striated
appearance to the surfaces of small blocks examined as opaque
objects. The edges of vertical sections (Plate VII., fig. 4),
are very instructive, for on them the vegetable fibres and shreds
of membrane which are seen indistinctly in the substance of
the sections project boldly, so as, I think, to compel the
observer to one conclusion, that they are vegetable tissues,
The dark-brown matter separating the yellow or ‘reddish-y vellow
masses of other cannels is of a similar kind to that in the
Torbanehill.

The general structure of the Torbanehill coal is further
illustrated by occasional opportunities of examining the rela-
tion which exists between it, as shown in Plate LX, figs.
3 and 4, and portions of easily recognisable vegetable struc-
ture. In fig. 3, an irregularly elongated, brownish-red mass,
without obvious structure, lies in coal having the same ap-
pearances as that found in the lower part of the seam, and
shown in Plate IX., fig. 4; and it will be observed, that from
this mass the septa between the yellow bodies of the coal
appear to radiate. In other parts similar masses are seen in a
structure more like that observed in the upper parts of the
seam. In these, too, the brownish-red matter stretches into
the yellow, and marks it out into a number of spaces. Again,
in Plate IX., fig. 4, a band of reddish and apparently fibrous
matter spreads out over a considerable quadrangular space,
dividing it into polygonal yellow spots ; and, on leaving it at
the opposite angle, what appear to be fibres are again col-
lected into a narrow band.

From the general description of the structure of this coal,

120 DR. REDFERN, ON THE TORBANEHILL

I excepted about the upper two inches of the bed, because
the yellow spaces there are much less visible, and there is
more uniformity in the appearances of various parts of sections.
Yet though the yellow matter of the upper part is not so ob-
viously Penked out into spaces by the dark-brown substance,
that part being, | presume, less carbonised than those lower
in the seam, the mass consists of alternate patches of yellow
and foadish-brown matter, and presents a very marked differ-
ence on horizontal and vertical sections. The vertical sections
of this part always show reddish-brown bands or patches,
sometimes branching, and always extending in the direction
of the lamine of bedding, like the eee bands of ver-
tical sections in the lower part of the seam (Plate VII, fig. 2).
A very gradual change of appearance is noticed on passing
from fel upper to fae lower parts of the seam, and in each of
these parts there are occasional patches which present the
ordinary appearances of the other, so I have no doubt that
originally both were formed nearly in the same way.

Crystals which polarise light very highly exist in all the
higher parts of the bed, but they are not found in the lower.
One is shown in Plate VII., fig. 2.

4th. Every horizontal section presents a number of more
or less rounded or angular bodies, in colour yellow, red, or
brown, and in size measuring from 1-500th to 1-2000th of an
inch (Plate VIIL., fig. 5). Most of them occur singly, but oc-
casionally two, three, or more lie close together; and I have a
preparation in which is a group of fifty or sixty of the smallest
of these bodies. When they occur singly, I think four or five

may generally be seen in a field of the microscope of about
1-60th of an inch in diameter. Sections taken from the upper
part of the bed are most favourable for their examination,
because such sections are of a lighter colour than others, and
can be made much thinner than they without breaking.

In vertical sections, such bodies are always found elongated
(Plate VIII., fig. 6), their length being equal to the diameter
of the spots Sieh on homeeatel sections, and their breadth
varying from 1-4000th to 1-1300th of an inch. Some of them
present the appearances of coiled fibres, and I believe that
such are either fragments of scalariform vessels, or portions
of fibre, probably from spiral vessels or cells. Others are
circular, both on horizontal and vertical sections, and are
undoubtedly spherical cells. Many which are somewhat
angular have an obviously double outline, like cells with thick
walls, and they have small conical or blunt projections stud-
ding them externally. Some have lost their definite outline
at particular spots, as if they had suffered from pressure or

AND OTHER VARIETIES OF COAL. 121

chemical changes. I know of no interpretation of these ap-
pearances, except that they are produced by free vegetable
cells, such as spores or pollen grains; but yet I cannot con-
fidently affirm that they are such. Whatever they are, they
are always to be found in other cannel coals.

5th. Scalariform tissue. Wherever a stigmaria is large
enough to admit of removal from the coal, scalariform tissue
may be found in it by thin sections, or the piaces where the
tissue exists may be selected by a common pocket lens from
any piece of coal containing fossiis, as before pointed out.
In some places, the side view of these vessels shows their
ladder-like character nearly as well as a section of a fresh
fern, as in the section from which Plate IX., fig. 1, was taken ;
but generally only very small portions of the vessels are found
in a tolerably entire state, the rest being bent or broken into
fragments of such small size, that of themselves they could
not be recognised as belonging to such tissue at all. Such
are some of the fragments found in the dark matter bounding
the yellow bodies of the coal. The influence of the agent
which has broken up this tissue may be distinctly traced in
my preparations from parts which show distinct scalariform
tissue, to others which present a uniform brownish-red mass
devoid of all appearance of structure. The absence of scala-
riform tissue in a large number of sections by no means
proves that its occurrence in the coal is merely accidental, for
I have already pointed out that on all pieces of the coal con-
taining stigmariz, scalariform tissue can be seen in great
quantity by a common pocket lens. Why it does not appear
more commonly on sections, made promiscuously in the coal,
will easily be understood by all who have experienced the
difficulty of obtaining thin sections of pieces of coal contain-
ing a structure so different in density from its other parts as
scalariform tissue. This tissue exists plentifully in other
cannel coals. I have a piece of Capledrae coal, which has a
surface of three or four square inches covered with it.

6th. I found in horizontal sections, reddish-coloured mem-
branes or expansions, as shown in Plate IX., fig. 6, giving off
from one of their surfaces a number of elongated and blunt-
pointed processes, not more than 1-200th of an inch long, and
at their base about 1-1000th of an inch broad. And on ver-
tical sections I noticed bodies similar to that shown in fig. 5
of the same plate. These differ greatly in size, and vary in
colour from a bright yellow in thin sections to a bright or a
dark-red in thicker ones. They present almost uniformly the
appearance of reddish or yellow bands, bent so as to enclose
irregular elongated spaces, which are always narrow and

122 DR. REDFERN, ON THE TORBANEHILL

sometimes of scarcely perceptible breadth. On their opposed
edges the bands are smooth ; on their exterior, they are almost
uniformly tubercular or pilose. I believe that the various
appearances presented by such sections as those from which
figs. 5 and 6 were drawn, result from bodies of a similar kind,
presenting themselves in different aspects in horizontal and
vertical sections. That they are vegetable membranes I have
no doubt, and I believe that they are the remains of more or
less globular and membranous vesicles, studded externally
with tubercles or hairs, and nearly smooth within. Are they
spores? Whatever they are, they increase the similarity
between the Torbanehill and other coals, for in the latter, in
house coals especially, they are very abundant. Very good
preparations of them may always be obtained from a thin
layer of house coal below the Parrot of Bathvale, west of
Boghead.

7th. Occasionally patches of dark-brown fragments are
met with. They, | think, are such as appear frequently
in small detached portions in the dark matter of the coal.
One of the patches seems to be a portion of a vessel contain-
ing a fibre ; if a fragment of a scalariform vessel, its colour
is totally different from that generally existing in that tissue
in the coal. Similar patches (as far as I can judge) occur
quite commonly in other coals.

Sawdust and Powder.—When reduced to small fragments,
as in the form of sawdust or powder, the Torbanehill coal
separates in the position of the dark matter into rounded and
flattened yellow masses, surrounded by a dark outline, or into
groups of these masses. There are also numerous elongated
fragments, yellow, reddish-brown, and dark-brown in colour,
and rounded or angular in different instances. I believe all
these appearances to be the result of an accumulation of vege-
table membranes, cells, and fibres, which originally formed
the mass. At any rate, whether vegetable or not, there is no
essential difference in the microscopical appearances presented
by small fragments of this coal and those of the Methill and
Capledrae cannel coals.

Coke.—The coke of the Torbanehill coal is greyish, dis-
tinctly laminated, of the same bulk as the coal from which it
is formed, and of but little use as fuel, from its containing so
small a quantity of fixed carbon. When reduced to frag-
ments, and examined microscopically, the coke of the upper
layers of coal presents a number of irregularly rounded black
masses, some of which have round or angular openings in
them. The coke of the lower layers presents a greater
number of elongated and angular fragments, such as might

AND OTHER VARIETIES OF COAL. 123

be produced by woody fibres. These characters of the Tor-
banehill coal are such as belong to the coke of the Methill
and Capledrae cannel coals. I feel satisfied that there are no
essential differences between them, and that they are not
distinguishable from each other hy their microscopical cha-
racters.

Ash.—Neither in this coal, nor any other, is there a trace
of vegetable structure in the ash, except where a very rare
silicification has taken place. Care must be taken, however,
that the mistake of confounding coke and the popular term
ashes with the scientific word ash be not repeated. The ashes
of coal (using the popular phrase) always contain vegetable
structures unconsumed; but from the ash of coal, as spoken
of by scientific men, all the organic matters have been driven
off by careful combustion, and nothing but earthy matter
remains.

It is important to distinguish the appearances first de-
scribed, which are general in the bed of coal, with some of
those last noticed, as only occurring occasionally in it. What-
ever explanation of the structure and mode of formation of
the bed may be adopted, it must be based on the appearances
which are delineated in Plate VII., figs. 1 to 4, rather than upon
those which are rare, selected from a number of specimens,
and shown in some of the other figures. It is always desira-
ble that the chemical composition of any body examined mi-
croscopically be taken into account ; because where the micro-
scope alone will not enable us to decide at once as to the
nature of an object, the microscopical and chemical charac-
ters, taken together, will often do so. This is precisely such
a case; for the conclusions which, I think, are to be drawn
from the structure of this bed of coal, are in a most important
manner corroborated and strengthened by the evidence of its
nature which chemistry supplies.

Were we to arrange and classify the known coals chemi-
cally and histologically, it would be found that anthracite
would take its position at one end of the scale and Torbane-
hill cannel coal at the other. Anthracite is almost pure car-
bon; Torbanehill contains less fixed carbon than any other
coal. Anthracite is very difficult to ignite, and gives out
scarcely any gas; Torbanehill coal burns like a candle, and
yields 3,000 cubic feet of gas per ton more than any other
known coal ; its gas being also of greatly superior illuminating
power to any other. Below the Torbanehill come the Wigan,
Capledrae, and Lesmahago coals. In lightness in colour of
the streak, Torbanehill stands highest, then come Methill,
Rochsoles, and Capledrae.

124 DR. REDFERN, ON THE TORBANEHILL

Structurally, I place cannel coals at one end of the scale
and anthracite at the other, common coals intervening. In
anthracite it is very difficult to show vegetable structure of
any kind; in common or house coal aes can be done more
easily ; and in cannels most readily of all. The cannels I
should arrange as follows:—Torbanehill, Bathvale, Bar-
bachlaw, Wemyss, Methill, Capledrae, Lesmahago, Wigan,
ccc!

Space will not permit me to enter upon a detailed descrip-
tion of the appearances presented by other coals when ex-
amined microscopically. I may state, however, that those
which the cannels present are essentially similar to those
which I have described in the Torbanehill coal. I refer, for
confirmation of this statement, to the figures of Methill,
Wemyss, and Capledrae coals. The house coals differ more
widely in structure from the cannels than these do amongst
themselves; yet I think the essential features of the structural
arrangements are nearly the same in all.

I know of nothing whatever to countenance an idea put forth
in the paper before named,—that all our coals are formed of
soniferous wood. On the other hand, I join geologists and
naturalists in admitting the obvious and constant presence of
fossil stigmariz, lepidodendra, ferns, mosses, &c., as evidence
that coal-beds were formed of such plants. 1 think the mi-
croscope affords the most conclusive evidence that the struc-
tural arrangements of coal are totally different from those of
wood; and that it points to the formation of coal, especially
of cannel coal, from a more or less fluid pulp, resulting from
maceration ad chemical changes taking place i in large masses

of vegetable tissues, such as are now going on in peat bogs,
especially i in those which are semi-fluid and quaking. Every
one knows the effect produced upon the potato, apple, turnip,
&c.— masses of vegetable cells—by boiling. The individual
cells are isolated, and a soft pulp results. The anatomist
knows that maceration produces precisely similar results on
animal and vegetable tissues; and it is in this way that I
believe the elements of the tissues of plants have been sepa-
rated from each other, partially disintegrated, and re-arranged
in a laminar form preparatory to their solidification into a
mass of coal. Whether such coal contain an enormous per-
centage of fixed carbon, and give out scarcely any gas, as in
anthracite ; or have but a small quantity of fixed carbon, and
give out a large quantity of gas, by the union of its hydrogen
with other carbon, as in the Torbanehill coal, seems to de-
pend upon the nature and amount of Ghewacll change to
which it has been subjected in its formation. In parts of

AND OTHER VARIETIES OF COAL. 125

many coal-beds, no crystalline or other aggregation of earthy
matter is detected by the microscope ; and yet chemistry de-
termines the presence of a considerable amount per cent. of
such matter. In such cases, I believe, the earthy matter has
been added to the vegetable part in a state of solution, or
fine molecular subdivision; whilst, where in other instances
crystals and earthy particles of considerable size occur, it is as
plain that many of these have been deposited as such origi-
nally, as is likely to be the case in the instances in which
beds of coal are formed in the beds of large rivers.

I will now endeavour to state very briefly the facts which
I believe to have been made out in this investigation, with the
conclusions which, I think, they warrant, as to the nature of
the Torbanehill coal.

Ist. That the whole seam is laminated—a sufficient expla-
nation of its tendency to split horizontally, and of its slaty
fracture.

2nd. That it abounds in fossil plants, especially Stigmarie,
which present well-preserved scalariform tissue on their sur-
face, in whatever part of the bed they appear.

3rd. That the small angular facets, seen in different planes
on every fractured surface, are produced by vegetable tissues,
easily recognised under low powers of the microscope.

Ath. That small blocks examined as opaque objects with
low powers present rounded yellow spots on their upper and
lower surfaces, and elongated yellow spots on their sides and
ends, bounded by dark-brown matter—appearances which are
produced by circular masses of yellow matter flattened ver-
tically.

5th. That thin sections, made horizontally, show rounded
yellow patches, often lobed ; but similar sections, made ver-
tically, show yellow spots, elongated in the direction of the
lamine. These yellow spots are bounded by dark matter, in
great part made up of fragments of vegetable fibre and mem-
brane. The addition of heat drives off the yellow matter as
gas, and leaves polygonal spaces, like the remains of vege-
table cells, in the mass generally, and in some of the yellow
bodies.

6th. That, besides the circular-flattened yellow bodies,
there are much smaller polygonal and flattened bodies of the
same colour, more uniform in diameter, sometimes with double
walls, resembling vegetable cellular tissue.

7th. That other appearances, such as would be produced
by masses of vegetable tissue sending off fibres or membranes
into the spaces between the yellow bodies, to constitute their
boundaries, occur here and there in the mass, confirming the

126 DR. REDFERN, ON THE TORBANEHILL COAL.

conclusions before drawn from the examination of the yellow
bodies of the coal.

8th. That circular or angular-flattened bodies, or spherical
ones, from 1-500th to 1- 2000th of an inch in diameter, occur
in considerable numbers in all sections of the coal, separate or
in groups, and resemble free vegetable cells, as spores, pollen
grains, &e.

Other bodies, of all sizes, up to the 1-20th of an inch, ap-
pearing more or less rounded and tubercular, or pilose, on one
surface, as seen on horizontal sections, and linear and bent on
vertical ones, appear here and there. Such appearances would
be produced by membranous capsules or cells, tuberculated or
pilose on the outside and smooth in their interior.

9th. That whatever opinions may be entertained as to the
interpretation of the appearances presented by this coal, it is
impossible, consistently with the facts, to deny that its sec-
tions present a remarkably regular arrangement of their parts,
quite different on horizontal ‘Gnd | vertical sections, and only
capable of explanation by supposing it to have been the re-
sult of crystallisation, or of animal or vegetable organisation,
That the coal is not a mass of crystals, is shown by the ab-
sence of the crystalline form, and, to some extent, by the fact
that it does not polarise light. Neither its structure nor
chemical composition offers the least countenance to the
supposition that it is of animal origin; whilst every par-
ticular of its structure, and the fact that it is mainly com-
posed of carbon, point to its being a mass of vegetable
matter,

10th. The Torbanehill resembles other cannel coals in its
geological position, its lamination, its variable thickness and
value in different parts of the seam—in 65} per cent. of it
being carbon; in burning like a candle when lighted at a
flame ; in crackling in the fire; in containing every chemical
ingredient found in other coals, and none but such as exist in
them; in its great gas-giving power ; in possessing a remark-
ably regular structure, differing widely on horizontal and ver-
tical sections, similar in every essential feature to that existing
in other coals, and only capable of explanation on the suppo-
sition that it is produced by vegetable tissues; and in being
everywhere full of fossil plants, easily recognised by the
naked eye.

11th. The Torbanehill differs from other cannel coals,—in
its colour being lighter; in its streak being lighter in colour
and dull; in its giving out far more gas than any other cannel ;
in containing fess car bon and more ash than most other Goals.
and more hydrogen than any known coal; and in its being

HUXLEY, ON THE ENAMEL OF THE TEETH. 12%

tougher and more easily reduced to thin sections than other
coals.

The differences it presents from other coals are, therefore,
non-essential ; not differences in kind, but in degree. The
Torbanehill coal differs from other gas coals in being the best
gas coal; it differs from other cannel coals in being the best
cannel.

On the Enamet and Dentine of the Teeta. By T. H.
Huxley, F.R.S.

Tue first part of the sixth volume of Siebold and Kolliker’s
‘ Zeitschrift fiir Wissenschaftliche Zoologie, published in
July of the present year, contains a paper by M. Edouard
Lent, ‘On the Development of the Dentine and Enamel of
the Teeth.’ It could only be a source of gratification to me
that any one should have been led fairly to “investigate a sub-
ject, by the perusal of a paper of mine published in this
Journal, even if his results were totally opposed to those at
which if had arrived ; and I do not think that, as a general
rule, controversial writing is worth the paper it is printed on
—assuredly, it is not worth the time it wastes. I should,
therefore, have had nothing to reply to M. Lent’s unfavourable
expressions with regard to my labours, were it not for two
circumstances, In the first place, M. Lent is a pupil of Pro-
fessor Kélliker’s, and appears to have worked under the eye
of that distinguished investigator. Indeed, the paper is so
completely sanctioned by Professor Kolliker, that T must regard
him as responsible for it. And in the second place, owing,
as 1 suppose, to M. Lent’s inexperience as an author (though
truly the superintendence of so practised a writer as Pro-
fessor Kélliker should have obviated this difficulty), his
paper is curiously inconsistent with itself, being in form a
severe criticism and refutation—but, in fact, a confirmation
—of the views I ventured to promulgate.

My paper was intended to establish two main points—
1. That there is no evidence that the dentine is formed by
direct conversion of pre-existing elements of the pulp. 2.'That
the enamel is not developed externally to the so-called base-
ment membrane, or membrana preformativa of the pulp, but
internally to it; Nasmyth’s membrane, which lies over the
enamel, being in fact continuous with the membrana pre-
formativa.

1. On this head, M. Lent adds no new fact or argument of
any kind. He simply repeats and confirms the statement
already made by Professor Kélliker—that minute gelatinous

128 HUXLEY, ON THE ENAMEL

processes may often be found passing from the surface of the
pulp into the dentinal canals (a statement which no one de-
nies), and then takes for granted Professor K6lliker’s purely
hypothetical interpretation of this fact—7. e., that these pro-
cesses are outgrowths of the “cells” of the surface of the pulp
—an hypothesis which is not supported, so far as I am aware,
by a shadow of direct evidence ; and it is to be remembered
that the fact is as well accounted for by my hypothesis as by
any other.

So much for the formation of the dentinal tubules. With
regard to the substance of the dentine, M. Lent does not seem
to have seen much more than myself; for he says that ‘it is
more probable —indeed certain” that the ‘ grund-substanz ”
is an “‘ excretion of the cells and their processes.” (p. 127.)

That is to say, M. Lent (2. e. Professor Kolliker) admits
that there is no new evidence to be brought forward as to the
formation of the dentine tubules, and that the substance of
the dentine is formed as I have stated it to be. Truly, then,
Ido not see where the “irrige ansicht” with which I am
charged lies.

At page 128 there is a very careless misstatement, which
one might be disposed to overlook in a student, but which is
utterly unpardonable in a production which has the advantage
of Professor Kolliker’s deliberate ¢mprimatur.

“* As regards Huxley’s erroneous view as to the formation of
the dentine, I will only briefly remark, that Huxley has been
so unfortunate as to have seen the dentine from above only.”
(p. 128.)

This is truly astounding, considering that at page 160 of my
paper I give particular directions how to obtain a profile view
of the dentine in undisturbed connexion with the pulp ; that
figs. 3 and 4 are careful representations of such profile views ;
and that I lay particular stress upon the advantages to be de-
rived from this mode of examination.

2. With regard to the development of the enamel, M. Lent
(a. e. Professor Kélliker) affords a confirmation of my views ;
all the more valuable, as it is evidently most unwillingly
wrung from him.

At page 129, M. Lent, after stating the ordinary theory of
the development of the enamel, says: “This simple theory
must, however, I believe, be given up, since Huxley has
made a discovery whose truth I must confirm—a discovery
which greatly enhances the difficulty of accounting for the
formation of the enamel.”

Again, at page 133: “ From what has been said, it is pretty
clear that the membrana preformativa, which may be detached

AND DENTINE OF THE TEETH. 129

from the enamel in the foetal tooth, subsequently becomes the
so-called cuticle of the enamel, as, indeed, Huxley states,”

Again, at page 130: ‘ When, however, I tested Huxley’s
new statements, the matter appeared in quite a new light—
the more as [ could never succeed in discovering a trace of a
nucleus in an enamel prism. Huxley, in fact, asserts “that
the enamel is formed beneath the membrana preformativa,
and that the membrana preformativa and cuticle of the enamel
are identical. In this point—as I have found by examining
the fresh teeth of a new-born child and those of a six months’
foetus—he is about right.”

I wish I could give the entire force of M. Lent’s exquisite
and polite acknowledgment of the truth of a fundamental fact
for all further theories of dental development, but here is the
original, for those who can appreciate it: “ HMiermit hat es
seine Richtigheit.”

In this part of M. Lent’s paper a second misstatement
occurs, somewhat more gross, if possible, than that which I
have already had occasion to notice.

At page 131 he says: “ Of nuclei, such as Huxley describes
and figures (in the membrana preformativa), I have seen
nothing.”

I have carefully re-examined my own paper, to see if I
could find any excuse for a statement so utterly contrary to
fact as this; and, for the sake of MM. Lent and Kolliker, I
really almost regret to say I can find none whatever.

I invariably call the membrana preformativa a structureless
membrane. I state that Nasmyth’s membrane is “ about
1-2500th to 1-1600th inch thick, perfectly clear and trans-
parent, and, under a high power, exhibits innumerable little
ridges upon its outer surface, which bound spaces sometimes
oval and sometimes quadrangular, and about 1-5000th of an
inch in diameter.” And I go on to say that this membrane
is nothing but the altered structureless membrana _prefor-
mativa. I am equally at a loss to discover any figures of
these ‘nuclei ;” though it is possible that in consequence of
the reticulation not having been carried evenly all over
Nasmyth’s membrane in fig. 2, a very careless person might
misunderstand the figure—the text, however, would at once
correct this misapprehension.

I have neither space nor inclination to follow M. Lent fur-
ther; as what has been said proves abundantly the only point
worth discussing at all: viz., that the two main facts asserted
in my paper are admitted to be bond fide additions to our know-
ledge ; in fact, one might almost fancy M. Kolliker address-
ing to M. Lent, Balak’s famous reproach to Balaam—“ |

VOL, III, K

130 SMITH, ON THE DETERMINATION OF

called upon thee to curse this people, and, lo! thou hast blessed
them these many times.”

So far as I am personally concerned, I care little enough
about being absorbed, after Professor Kolliker’s ordinary
fashion, in the next edition of the ‘ Mikroskopische Anatomie,’
where we shall, I doubt not, read, “I and Huxley have made
out that the enamel is formed under the membrana preforma-
tiva,” &c., kc. But I think that Professor Kolliker will do
well to reflect whether he is likely to increase his most de-
servedly high reputation, by encouraging in a student a dis-
ingenuousness of which he himself, I hope, would be heartily
ashamed.

I may add, in conclusion, that there are, I believe, two very
good minor grounds of cavil in my paper. One is at page 159,
where [ state incidentally that Professor Kolliker does not
mention Nasmyth’s discovery in his ‘ Mikroskopische Ana-
tomie ’—an error for which I cannot account, and for which I
can only apologise, as a complete oversight. The other is the
description of the cement of the calf’s tooth at page 162; in
which, a subsequent examination has led me to think there are
errors of interpretation. I have had no leisure to re-examine
this point, and I recommend it to MM. Lent and KoOlliker, if,
as it would seem, they have some unaccountable source of
satisfaction in finding me wrong—a thing I do myself, quite
without satisfaction, every day.

On the Determination of Species in the Diatomacez. By
the Rev. Wm. Smirn, F.L.S., Professor of Natural History,
Queen’s College, Cork.

Ir has been said, that “Synonymy is the opprobrium of
Science,” and not without reason; for synonymy owes its
existence to imperfect knowledge, imperfect observation, or
imperfect judgment.

Still, as few authors can be required to possess a thorough
acquaintance with the literature of science, and still fewer can
be supposed to exercise perfect accuracy of eye and unerring
powers of judgment, synonymy is, to a certain extent, unavoid-
able.

Facts or circumstances first received by one student, will
be again rediscovered by a subsequent observer ignorant of
the former record, and registered as new; and known pro-
perties or characters, hitherto regarded as of transient or
inferior importance, will be seized upon by a new writer, and
made the basis of important distinctions.

SPECIES IN THE DIATOMACES. 131

The multiplication of synonyms may, however, be restrained
within moderate limits, if the scientific observer will exercise
due caution in the creation of new names, carefully abstaining
from designating the subjects of his study, until he has made
himself, as far as possible, acquainted with the labours of his
predecessors in the same field ; and until he has acquired,
from a wide examination of allied forms, in every stage and
condition of growth, sound and invariable rules, by which to
determine how far certain differences are to be regarded as
specific distinctions, or as accidental or transitional varia-
tions.

In a branch of study to which many are attracted by the
excitement of novelty, and the laudable desire of discovery,
there is some danger that these important cautions may be
overlooked or neglected ; and if the student of larger experi-
ence can, by his remonstrance, curb the impetuosity of such
inquirers or impose upon them safe and certain rules of
observation and discrimination, so that the new science shall
not be burthened with an unnecessarily extended nomenclature,
he will be doing some good service, and saving future ob-
servers much painful and unprofitable labour.

It is with this view that I venture to make a few remarks
upon the discrimination of species in the Diatomacez, a
department of nature now inviting and receiving much atten-
tion, and in which it is probable many real and presumed
discoveries, as regards new forms, will rapidly be made by
the host of observers who have been attracted to the study.

Several years of close observation of these organisms have,
I believe, enabled me to clear up some of the more difficult
points in their structure and growth, and led me gradually to
the adoption of certain views, as to specific characters in their
regard, that it may be of some utility at the present moment,
and in anticipation of the contents of the second volume of
my Synopsis, to lay before the public.

The ordinary Diatomaceous frustule seems to owe its
reproduction to the protoplasmic contents of the sporangial
frustule, formed by the process of conjugation. These syo-
rangia, like the seeds of higher plants, often remain for a long
period dormant, and are borne about by currents, or become
embedded in the mud of the waters in which they have been
produced, until the circumstances necessary to their develop-
ment concur to call them into activity. At such times their
silicious epiderms open to permit the escape of the contained
endochrome, which is resolved into a myriad of embryonic
frustules ; these either remain free, or surround themselves
with mucus, forming a pellicle, or stratum, and in a definite,

K 2

132 SMITH, ON THE DETERMINATION OF

but unascertained period, reach the mature form of the
ordinary frustule.

The farther growth of the individual cell seems now to be
almost entirely arrested by the formation of the silicious
valyes, and the multiplication of these forms, of the size thus
reached, goes on with inconceivable rapidity, by means of
self-division.

The size of the mature frustule before self-division com-
mences, is, however, dependent upon the idiosyncracy of the
embryo, or upon the circumstances in which its embryonic
growth takes place ; consequently a very conspicuous diversity
in their relative magnitudes may be usually noticed in any
large aggregation of “individuals, or in the same species col-
lected in different localities.

It may also be easily conceived, that while a typical outline
of its cell must be the characteristic of a certain species, such
outline may to some extent be modified by the accidental
circumstances which surround the embryo during its earlier
growth and development. A lanceolate form may become
linear, elliptical, or even somewhat oval, by the pressure of
surrounding cells; and acute ends may be transformed into
obtuse or rounded extremities.

Those who understand the process of self-division will see
here a sufficient reason for the occurrence of multitudes of
frustules, deviating from the normal form, or even for the
existence of myriads, at one spot, all having a form different
from the type, the single embryo from which they haye all
sprung by self-division (which process stereotypes the shape
with which it commences), having from some accidental cir-
cumstances become modified in its outline.

It follows then, from these considerations, that neither size
nor outline are sufficient to enable the observer to determine
the species of a Diatomaceous frustule. If he has the means
of comparing specimens in sufficient numbers, and from
various localities, he may fix with tolerable certainty upon
the magnitude and form which may be regarded as the
average and type of the species; but without such oppor-
tunities, a reliance upon such characters will inevitably lead
to the undue multiplication of species, and to a confused and
erroneous nomenclature.

There are three circumstances which seem to me to be of
essential importance as regards the specific character of the
diatom: first, the structure of the valve ; second, the habitat ;
and third, the arrangement of the endochrome in the living
frustule. I have placed the structure of the valve first in
order, because this is a feature which can be ascertained in

SPECIES IN THE DIATOMACE. 133

every condition under which these forms present themselves,
whether in a living, dried, or fossil state; and also because it
appears to me to be the most constant and obvious character
of such organisms. These varieties of structure arise from
the modes in which the silex combines with the cellulose of
the epiderm, and this combination seems to follow certain
and invariable laws which are subject to no derangement from
the external circumstances in which the growth of the embryo
may take place. The structure of the valve reveals itself in
the striation, in the character of the striation, may there:
fore be found a good specific distinction. Whether the striz
are costate or moniliform, parallel or radiate, reach the
median line, or are absent from a greater or lesser portion of
the valvular surface, and numerous other features which may
exist, separately or in combination,—these appear to me to be
circumstances which the observer who wishes to discriminate
and determine the species should most carefully regard. The
relative distances of the striz, and their greater or less dis-
tinctness, (which are not, by-the-bye, always identical cha-
racteristics,) are also features which may be safely and
properly recorded; but | am not certain that these features
may not, to a slight extent, be modified by localities and age,
and am disposed to believe that they are certain guides only
when we have made allowance for these conditions ; and that,
while they are constant in frustules originally from the same
embryo, they may slightly vary in those which owe their birth
to different embryonic cells.

In describing a species, we should therefore carefully note
the character of the striation, and state as nearly as possible
the average number of the striae. The dry valve will frequently
aid in such determinations, the presence and extent of the
striation being usually indicated by the colour of the valvular
surface, even when the power employed fails to detect the
striae themselves; the differences in colour not unfrequently
answering to the relative distances, or distinctness of the
markings.

Next to the striation of the valve I have placed locality,
as a means of arriving at a specific distinction. Where forms
are closely allied, this circumstance will often aid in their dis-
crimination ; for not only do I regard it as established that no
fresh-water species will live in a marine habitat, nor a marine
species flourish under the predominating influences of springs
and rivers; but I believe that certain species are far more
special in their tastes, some selecting mountain torrents, others
clear and still waters ; some rejoicing in the deltas of rivers,
and others fixing their habitations in boggy pools, or alpine

134 SMITH, ON THE DETERMINATION OF

lakes; some being littoral, and others only found in the
deeper parts of the ocean. When structural differences are
not obvious, such circumstances as these will not unfrequently
assist the inquirer to resolve his doubts, and assign to a form,
a position and a name.

And lastly, the arrangement of the endochrome, in the living
frustule, will be found to confer a specific character, one far
more certain than habitat; but from its being less easily, or
less frequently within the observer’s notice, not so practical
in its application.

Those who have the means of examining the living cell are
well aware that there is in every species a distinct feature
conferred by the position of the cell contents; in one the en-
dochrome is closely applied to the inner surface of the valve ;
in another aggregated in the centre of the frustule ; somietinnies
sparingly diffused throughout the interior; or again exhibit-
ing a radiate or stellate arrangement ; at all times having one
or several oily globules, wiich occupy in different species
different positions, but are constant in number and situation
in the same species.

These characters are not always within reach of the ordi-
nary microscopist, who contents himself with an examination
of the silicious valve in a dried or prepared condition ; but
the systematist, who desires to define and discriminate, will
not neglect these features, and will hesitate to decide between
closely allied forms until he has the means of scrutinizing the
living frustules, and noting the differences which exist in the
position and arrangement of their cell contents.

It will be apparent from these remarks, that the determina-
tion of species in the Diatomacez is at all times a task of
difficulty, and that this difficulty is much enhanced when the
observer does not enjoy the opportunity of examining these
organisms in their living state, or has only prepared or fossil
specimens, within the reach of his observations.

In such a case the student is disposed to rely too much
upon the obvious characteristics of size and form; now it
often requires a careful examination of specimens edllectedla in
various localities, and in every condition of growth, to enable
the observer to fix upon the size which may be regarded as
an average, or upon the outline which ought to be accepted
as typical of the species.

To adopt as specific a shape or size that occurs in but
one gathering, whether the individuals therein be more or
less numerous, is, I feel persuaded, a most fallacious method
of procedure. And although the striation is at all times an
important guide, it often happens that this feature is so nearly

SPECIES IN THE DIATOMACE. 135

alike in allied species of the simpler forms, such as Cocconema,
Cymbella and Navicula, that our determination must be in-
fluenced by less important considerations, and the habitat,
outline, and arrangement of the cell-contents, all require to be
brought under review before we should feel justified in con-
stituting a species.

It may be said that, to describe and figure every variety
that presents itself to our notice, will aid future observers in
the study and determination of these forms. If practicable,
this course might be a desirable one; but this is no more
possible in Diatoms than the representation of every leaf,
which varies however slightly in form and size from another,
would be possible in our description of a forest-tree ; and the
elevating of such diversities into specific distinctions, and the
conferring a distinct name upon each aberrant individual, seems
to me a course more likely to confuse and to embarrass than
to lead to a clear arrangement or satisfactory system. Besides,
it overloads a scientific arrangement with a cumbrous nomen-
clature, which unduly taxes the time and patience of future
observers to simplify or remove.

It is, therefore, far better to expend our labour in endea-
vouring to combine, unite and harmonize the interminable
varieties of nature, and thus in a few brief and simple
terms to embrace a number of seemingly different, but truly
identical, specific forms, than to encumber science with a
phraseology which alarms the general inquirer, and enhances
the labour of the more studious observer.

( 136 )

TRANSLATIONS.

On the SrructurE and Systematic Position of the Rotirera.
(Abstract of Dr. F. Leydig’s observations.)

In the ‘ Zeitschrift f. Wissenschaftliche Zoologie’ of Siebold
and Kolliker, Vol. VI. Part 1, is a valuable Memoir by Dr.
F. Leydig, upon the structure and systematic position of the
Rotifera; illustrated with four plates of most elaborate and
beautiful figures, displaying the structure of, or other parti-
culars relative to Stephanoceros Eichhornit, Floscularia appen-
diculata, Tubicolaria najas, Pterodina patina, Polyarthra
platyptera, Scaridium longicaudum, Notommata Sieboldit, N.
centrura, Eosphora najas, N. aurita, N. tardigrada, Euchlanis
triquetra, Stephanops lamellaris, Ascomorpha germanica, No-
tommata myrmeleo, Euchlanis triquetra, Noteus quadricornis,
Brachionus Bakeri, B. rubens, Euchlanis unisetata, &ce.

The first part of the paper embraces descriptions of the
various species observed by the author, as occurring in the
neighbourhood of Wiirzburg ; to which succeeds an exposition
of the condition of organization of the class in general; and
the last part of the essay is devoted to a determination of the
systematic position of the Rotifera.

The new species described by the author are—

Floscularia appendiculata.
Notommata Sieboldii.

an tardigrada.
Ascophora germanica.

The second part of the paper, or that embracing the descrip-
tion of the structure of the Rotifera in general, though too
long for insertion in this Journal, is a most valuable contri-
bution to our knowledge of the structure, both histological
and general, of those creatures; and must, of necessity, be
studied by all who pay attention to the subject.

Though not agreeing with Dr. Leydig in his views respect-
ing the alliance of the Rotifera with the Crustacea, believing
with Mr. Huxley that they are more closely related to the
Annelids, we have thought that the Chapter on the Systematic
position of the Rotifera might be interesting to those who
wish to see both sides of the question ; and the more especially
as it contains many interesting and important observations on
the subject to which it is devoted.

ON THE STRUCTURE OF THE ROTIFERA. 137

We have also appended the author’s Systematic arrangement
of the Rotifera.

ON THE SYSTEMATIC POSITION OF THE ROTIFERA.

Formerly placed among the Infusoria, of which they formed the second
class in the classification of Ehrenberg, it has been latterly admitted by
all systematic writers, that the RorirEra possess nothing in common
with the animals truly belonging to that class, or the polygastrica of the
Berlin Professor: but that, in respect of their complex structure, they
represent a higher type of organization. Opinions, however, are still
divided on the question, whether the Rotifera, as Burmeister believes,
belong to the Crustacea, or should be referred to the Annelids, in accord-
ance with the opinion of Wiegmann, Wagner, Milne-Edwards, Berthold,
V. Siebold, and others.

If the truth were always with the majority, we should undoubtedly be
obliged to place the Rotifera in the class of Annelida; but I believe,
nevertheless, that Burmeister is in the right, though opposed to all the
other observers above named. J also conceive that the Rotifera are much
more closely allied to the Crustacea than to the worms ; and, by comparing
the conditions of organization of the two classes, shall venture to support
this view in the following observations.

It may first be mentioned, that so far back as 1824 Nitzsch asserted,
that the Rotifera resembled the Entromostraca ; and, what certainly
deserves attention, Ehrenberg himself, though placing them with the
Infusoria, frequently remarks upon their resemblance to the Crustacea
and Entomostraca ; thus, in his great work, p. 410, he says, that the
““ spicules, beards, and setz’’ of many species might be compared with the
arms of the Daphnic ; and in p. 411 he remarks, that many Rotifera carry
about their eggs attached to them, ‘like the Crustacea ;” and speaks to
the same effect in many other places. Dujardin also notices similar resem-
blances with Cyclops, Cypris, &c.; as, for instance, at pp. 574 and 575
of his work.

If the systematic position of the Rotifera were to be determined mainly
from their external figure, the result would certainly be more in favour of
the Crustacean than of the Annelid’type. No annelid has articulated motile
organs, whilst, on the contrary, the possession of such organs in a per-
fectly symmetrical form is a fundamental character of the Arthropoda.
The majority of the Rotifera are not furnished, it is true, with a pair of
feet, although they have a single annulated, or jointed foot, containing no
part of the viscera, but which is applied solely to the purpose of loco-
motion. Furthermore, if the rest of the conformation of the body he
regarded, it is obvious at once that a Huchlanis, Salpina, and, in short,
all whose cuticle has acquired the hardness of a lorica, are more closely
approximated to a crustacean than toa worm. For in the whole vermi-
form division I am unacquainted with any form whose cuticle is indurated
to the same extent.

The muscular structure also approximates, in many Rotifera, more
nearly to the Arthropoda than to the Annelids. In no animal of the
latter class have genuine transversely striped muscles hitherto been seen ;
that is to say, muscles whose contents are divided into minute quadran-
gular particles, like those of the muscles of vertebrate animals.

That the motions of the body of many species recall in a striking
manner those of the Crustaceans has already been noticed.

If the nervous system be considered, its similarity with that of the

138 ON THE STRUCTURE AND

lowest Crustaceans cannot escape recognition. In the Rotifera it consists
simply of a cerebral ganglion, with branches radiating from it; there is
no abdominal chord, nor any chain of ganglia. But is the nervous system
of the Lophyropoda more developed? In the Daphnia, even, we are
acquainted only with a cerebral ganglion and nerves proceeding from it;
and, consequently, know of no grounds upon which to establish the law,
that a central nervous system, consisting of a ganglionic ring surrounding
the pharynx, and of a chain of abdominal ganglia proceeding from it,
belongs to the Crustacea as a fundamental character.

Moreover, the manner in which the sensitive nerves terminate peripher-
ally in the Rotifera corresponds precisely with what I have described,
regarding this point, in the Crustacea and Insecta; and nothing like which
is at present known to exist in the class ‘‘ Vermes.” Lastly, I shall not
repeat at length, but merely remark, that the eye-spots apparent on the
nervous centre of the Rotifera approximate most closely to the similar
structures of the Crustacea, as Ehrenberg has not failed to indicate.

The disposition and texture of the alimentary canal, in an inquiry into
the systematic position of the Rotifera, afford no decisive evidence in
favour of one view or the other, since many Annelids also have a complex
horny masticatory apparatus ; still, with respect to this 1 would remark,
that the masticatory apparatus of young Daphnice (1 have examined, for
this object, the deep yellow-red young of a very large species, Daphnia
maxima ?) presents a pretty close similarity with that of many Rotifers,
inasmuch as the two opposed jaws expand into a plate, which is toothed
with numerous transverse ridges, exactly like the corresponding plate in
Lacinularia.

The glandular lobate appendages placed upon the stomach in the Cirri-
peds, which have been explained as “ salivary glands,” might, perhaps, be
regarded as analogues of the ventricular glands of the Rotifera. Similar
organs, however, also exist in many of the dorsibranchiate Annelids ;
many Annelids also, like many of the lower Crustaceans, are alike in the
circumstance that the liver is represented simply by large cells, with
peculiar contents, situated in the wall of the stomach or intestine. Should
any one find an objection to the arthropodous type in the deficiency of an
intestine in some Rotifers (Notommata anglica, N. Sieboldii, &c.), he may
recall the neuropterous larva of Myrmeleon, in which, as is well known,
the faeces are also discharged by the mouth ; the rectwm being transformed
into a spinning organ. But with respect to the intestinal tract of many
Rotifers (as Huchlanis, Stephanoceros, &c.), what especially recalls the
condition of that part in the lower Crustacea, is its peculiar bell-like
movement, which is precisely similar to that with which we are acquainted
in the intestine of certain parasitic Crustaceans (Achthenes, Tracheliastes,
&c.)

As to the substance which I have pronounced to be a wrinary secretion,
the close relations which obtain, with respect to it, between the Rotifers
and the larva of Cyclops, cannot fail to be recognised; whilst anything
allied to it is wholly wanting in the Annelids.

Lastly, the anatomical and physiological phenomena relating to the
sexual life speak loudly enough in favour of the proposition that the Roti-
fers should be ranked with the Crustacea. I would not lay much stress
upon the circumstance that they produce two kinds of ova,—the so-termed
“summer” and ‘ winter-eggs” (the latter in 7riarthra, in the structure
of their shell present much similarity with the ephippian eggs of Daphnia),
or that many species carry their ova about with them ; for, as regards
these particulars, the genus Clepsine among the Annelids might be named
as one in which the same thing takes place. The coloured oil-globules

SYSTEMATIC POSITION OF THE ROTIFERA. 139

also, met with in the vitellus of many Rotifers, and indicative of a Crus-
tacean type, may be left out of consideration. But of greater importance,
perhaps, is the striking analogy existing between the male Rotifers—
which in a certain sense may be said to be aborted—and those of many
Crustaceans. Who will not remember the diminutive, male parasitic
Crustaceans, which Nordmann discovered on the female individuals of
Achtheres, Brachiella, Chondracanthus, and Anchorella, and Kroyer in
other Lernzopoda and Lernez ?

And the reason that we are only just beginning to become acquainted
with separate males of Rotifers is probably due to the same circumstances,
—appearance at a certain time of year, diversity of figure from that of the
female—as those owing to which we have not yet discovered the males,
for instance, of Ergasilus, Polyphemus, Limnadia, Apus, &c.

If the development also of these creatures be regarded, it will be found
in favour of our view; for, with respect to several species, it has been
shown that the young, at its liberation from the ovwm, has not got the
form of the adult animal, and, consequently, must undergo a metamor-
phosis. And is not the subsequent diminution, and even complete dis-
appearance of the eyes, which exist in the young condition of the animal,
a farther indication of an approach towards certain Crustacean forms ?

Whilst the structural conditions hitherto mentioned more or less power-
fully support the view of the Crustacean nature of the Rotifera, they are,
on the other hand, separated from the Crustaceans by the condition of the
respiratory organs and the presence of vibratile cilia, and approximated to
the Annelids; but in both these respects they equally approach the
Echinodermata ; for, as has been said above, the proper vibratile organs of
Synapta digitata appear to me to be structures equivalent to the ‘ vibra-
tile organ” of the Rotifer.

But in the determination of the systematic position of an animal, the
question must depend, as it seems to me, upon the fact, whether the sum
of the resemblances is greater than that of the differences, as respects the
animal groups with which the animal might be supposed to be associated.
In applying this law to the subject under discussion, we find that the
number of conditions allying the Rotifers with the Crustaceans far exceeds
that of the properties possessed by them no¢ in common with the Crus-
tacea. I consequently regard it as fully justifiable to rank the Rotifera
as a special order of Crustacea, and propose, from the distinctive character
exhibited in them, to denominate them ‘‘ ciliated Crustaceans” (Wimper-
krabse). They necessarily stand at the commencement of the Crustacean
class ; since, in the structure of their respiratory organs, they continue to
be allied with the Annelids. Huxley (1. c.) has regarded them as Annelids
possessing permanently the form of the Echinoderm-larva, and has ex-
pressed this comparison in diagrammatic figures (1. c., Plate III.), in
which he places Lacinularia opposite an Annelid larva, Melicerta opposite
to that of Asterias, Philodina to that of Holothuria, Brachionus to the
larva of Stpunculus, and, lastly, Stephanoceros to the larva of Hchinus.
Although the ingenuity of this attempt must be admitted, still I am
unable to adopt the view of the English observer, but am compelled, from
the considerations above detailed, to declare myself an adherent to Bur-
meister’s view, as the only one agreeing with my own.

CLASSIFICATION OF THE CILIOCRUSTACEA.

It is obvious that the arrangement of the Ciliocrustaceans, or Rotifers,
as proposed by Ehrenberg, must be changed, inasmuch as the principle

140 ON THE STRUCTURE AND

upon which it is founded rests upon an erroneous basis. Polytrocha
and Zygotrocha do not exist, nor is it at all admissible, that in many
species the gelatinous envelope should be termed a Jorica, whilst in others
the hardened cuticle should be understood under the same term. Similar
criticisms upon Khrenberg’s system have before been made from other
quarters, although no one, except Dujardin, has proposed a new arrange-
ment. The latter naturalist has endeavoured to arrange the Rotifers by
taking the mode in which the movements are effected as the basis of his
system ; in accordance with which he has erected the following orders :—

Ordre I.—Systolides fixés par un pedicule.
1. Famille. Flosculariens.
2. Famille. Melicertiens.

Ordre II.—Systolides nageurs.
3. Famille. Brachioniens.
4, Famille. FPurculariens.
5. Famille. Albertiens.

Ordre III.—Systolides alternativement rampants et nageants.
6. Famille. Rotiferes.

Ordre IV.—Systolides marcheurs.
7. Famille. Tardigrades.

With the exception of the Tardigrada, I decidedly prefer Dujardin’s
system to that of Ehrenberg, founded as it is upon a correct principle of
arrangement, and recommended by its simplicity.

Probably, however, the Rotifera may be arranged according to their
forms ; whether they are cylindrico-conical, or sacciform, or compressed,
together with which, as further characters, the condition, presence, or
absence of the foot, may be employed. Proceeding upon this idea, I
would venture to propose something like the following arrangement.

CILIOCRUSTACEA.

Animals with a jointed body and a ciliary apparatus at the cephalic
extremity. The nervous system consisting of a cerebral ganglion, and
filaments radiating from it. Digestive and respiratory systems much
developed. No heart or blood-vessels. Sexes separate. The female pro-
duces ‘‘ Summer” and *‘ Winter-ova.” Many undergoing metamorphosis.

A. FIGURE BETWEEN CLAVATE AND CYLINDRICAL,
I. With elongated, transversely-ringed, attached foot.

1. Fuoscunaria proboscidea, Ehrenberg ; ornata, Ehr.; appen-
diculata, i. s.

STEPHANOCEROS Hichhornii, Ehyr.; glacialis, Perty.

(icisres erystallinus, Ehr.

ConocuiLus volvox, Khr.

LACINULARIA socialis, Khr.

. Limntas ceratophylli, Schrank.

. TUBICOLARIA najas, Ehr.

. MELICERTA ringens, Schrank.

The genera Ptygura and Glenophora, Ehr., which, according to their
forms, would also belong to this division, do not appear to me to be fully-
grown animals at all, but undeveloped forms; and it is not improbable,
as Ehrenberg himself was at one time disposed to believe, that Ptygura is
the young of Melicerta ringens.

GO I o> OTHE go be

SYSTEMATIC POSITION OF THE ROTIFERA. 141

The genus Cyphonantes, instituted by Ehrenberg upon two animalcules
found in water from the Baltic, is certainly not a Cilio-crustacean at all.
From the figure alone, and still more from the description, it is obvious
that this creature has no alliance whatever with a Rotifer, except in the
ciliary movement. It is probably the Jarva of some marine animal, and
I should suppose that of an acephalous mollusc.

Il. With elongated, jointed foot, retractile, like a telescope.

. CALLIDINA elegans, Ehr.; var. rosea, Perty ; cornuta, Perty.
. Hyvrias cornigera, Ehr.

. TYPHLINA viridis, Ehr.

Rovirer vulgaris, citrinus, erythreeus, macrurus, tardus, Ehr.
. AcTrnuRus neptunius, Ehr.

. Monouasis conica, Ehr.

. PutLopina erythrophthalma, roseola, macrostyla, citrina, acu-
leata, meygalotrocha, Ehr.

AONB e doe

III. With elongated, jointed, non-retractile foot.

1. Scaripium longicaudum, Ebr.
2. Drvocnaris Pocillum, tetractis, paupera, Khr.

IV. With a short foot and long pedal forceps.
1. Norommata (?) tigris, longiseta, Ehr.
2. Monocerca rattus, bicornis, valga, Ehr.
8. Furcunartia gibba, Forficula, gracilis, Ehr.
4, Micropon clavus, Ehr.

The genus Microdon, which I have never seen, would appear, from the
observations respecting it communicated by Ehrenberg and Perty, to be
worth attention. I imagine it may represent a male Cilio-crustacean.

V. With short foot and pedal forceps, which are of equal length with, or
somewhat shorter or longer than the foot.

1. Hypatina senta, brachydactyla, Ehr.

2. PuevrotrocHa gibba, constricta, leptura, Ehr.

3. Furcuuaria Rheinhartii, Ehr. (probably not a Furcularia,
but a Notommata).

4, NorommMatTa tuba, petromyzon, saccigera, copeus, centrura,
brachyota, collaris, najas, aurita, gibba, ausata, decipiens,
felis, parasita, tripus, Ehr. ; tardigrada, n. sp. ; vermicu-
laris, Duj. ; roseola, onisciformis, Perty.

5. Linpra torulosa, Duj.

6. SyncHzTA pectinata, baltica, oblonga, tremula, Khr.

7. Diauena grandis, forcipata, aurita, catellina, conara, capi-
tata, caudata, Ehr.

8. Ratrratus lwnaris, Ehr.

9. DistemMaA forficula, setigerum, marinum, forcipatum, Khr.

10. TRIOPHTHALMUS dorsualis, Ehr.

11. Eospora najas, digitata, elongata, Ehr.
12. CycLogENna lupus, elegans, Ehr.

13. THEorus vernalis, uncinatus, hy.

Ehrenberg’s genus, Enteroplea hydatina, is the male of Hydatina senta ;
and his Notommata granwaris stands in the same relation to Notommata
brachionus, which latter genus, however, is placed far more correctly
under the genus Brachionus than under Notommata. Diylena granularis,
Weisse, lastly, is the male of D. catellina, Ehr.

142 ON THE STRUCTURE OF THE ROTIFERA.

The genus Lindia, Duj., is said to be without cilia on the head, which
I much doubt.

VI. Without foot.

1, ALBERTIA.

Includes the A, vermiculus, found by Dujardin in the abdominal cavity
of the Earthworm, and in the intestine of the Limacina; and A. erystal-
lina, discovered by Schultze in the intestine of Nais littoralis.

I have long ago noticed a similar Albertia in the intestine of Nais elin-
guis. On comparing the drawings I then made with the figures given by
Schultze, I perceive the closest correspondence with his fig. 13. (Beitrage
zur Naturgesch d. Turbellarien, Taf VII. &c.) So that it may probably
be the same species.

B. Figure sAccirorm.
T. Foot short.

1. Norommata clavalata, myrmeleo, syrinaz, Ehr.
2. DiauENA lacustris, Ehr.

TI. Foot absent.

1. Notommata anglica, Dalrymple ; Steboldiz, n. sp.
2. PotyarTuRa platyptera, Khr.

3. TRIaRTHRA longiseta, mystacina, Khr.

4, AscomorPHA helvetica, Perty ; germanica, u. sp.

C, FIGURE COMPRESSED.

a. Depressed from above downwards.
I. With a foot.

1. Eucnuants triquetra, Hornemanni, luna, macrura, dilatata,
lynceus, Ehr.; wnisetata, n. sp.; bicarinata, n. sp. (E.
bicarinata, Perty, I consider a Salpina).

2. LEPADELLA ovalis, emarginata, salpina, Ehr.

3. Monostyia cornuta, quadridentata, lunaris, carinata, Ehr.

. Meroprrpia lepadella, acuminata, triptera, Ehr.

. STEPHANOPS lamellaris, muticus, cirratus, Ehr. (Dujardin

declares that S#. muticus is Lepadella ovalis).

. SQUAMELLA bractea, oblonga, Ehr.

. Noroconta Hhrenbergii, Perty.

. Noreus quadricornis, Ehr.

. Bracuionus pala, amphiceros, urceolaris, rubeus, Miilleri,

brevispinis, Bakeri, polyacanthus, militaris, Ehr.

10. Preropina patina, elliptica, clypeata, Khr.

II. Foot absent.

1, AnuREA quadridentata, squamula, falculata, eurvicornis, bi-
remis, striata, inermis, acuminata, foliacea, stipitata, tes-
tudo, serrulata, aculeata, valya, Ehr.

OOND CP

8. Laterally compressed.
1. SALPINA mucronata, spinigera, ventralis, redunca, brevispina,
bicarinata, Ehr.
2. MasticocErca carinata, Ehr.
3. Monura colurus, dulcis, Ehr.
4, CoLURUS uncinatus, bicuspidatus, caudatus, deflecus, Ehr.

er143

REVIEWS,

UEBER DEN ORGANISMUS DER POLYTHALAMIEN (FORAMINIFEREN), nebst
Bemerkungen tber die RuizopopEN in Allgemeinen. Von Max Sic-
MUND SCHULTZE, Griefswald. Mit vii. color, Kupperft. (On the Organi-
zation of the Polythalamia (Foraminifera), together with Remarks on
the Rhizopoda in general.) Leipzig, 1854: pp. 68; with 7 coloured
Plates.

Naturalists in general, but especially those whose attention
is more particularly given to microscopic research, will at
length be gratified with the appearance of a satisfactory work
upon the Rhizopoda. And the more so as it would appear
to be but the precursor of further labours in the same field
by the author, who has already proved himself a most able,
assiduous and conscientious observer, by his valuable memoir
on the Turbellariz, published in the Wurzburg Transactions,
and by other papers, in Miiller’s Archiv. and elsewhere, on
different subjects of natural history.

He intends apparently to devote himself particularly to the
study of the Rhizopoda, and has made large collections of
recent and fossil forms for this purpose. From this source,
therefore, in addition to the promised work on British Fora-
minifera to be published by the Ray Society, and upon which
Drs. Carpenter and Williamson are, we believe, now at work,
we may expect very great additions to our knowledge of this,
as yet, obscure and confusing class of creatures ; the study of
whose remains, however, is of the utmost importance, par-
ticularly in a geological point of view, from their vast range
in both time and space throughout nearly all geological for-
mations. And their importance appears to be much enhanced
by the consideration of the astounding fact recorded by Pro-
fessor Bailey, and noticed in the last number of this Journal
(p. 89), with respect to deep soundings in the Atlantic, which,
it is believed, are the deepest ever submitted to microscopic
investigation. The results of this examination go to prove
that the bottom of the North Atlantic Ocean, from a depth of
60 fathoms to that of more than two miles, is literally nothing
but a mass of microscopic shells; which it is shown must
have lived at the depth where they are found, and not in the
superincumbent water—these shells are almost all those of
Foraminifera.

The present work of Dr. Schultze, which, as we have ob-

144 DR. SCHULTZE, ON THE RHIZOPODA.

served, is only the commencement of his labours in this de-
partment, is limited to the object of communicating faithful
observations with respect to the structure and vital phenomena
of the testaceous marine Rhizopoda, and to bring our know-
ledge of them, so far as possible, aw niveau with the rapid
advances which have of late years~been made in that of the
other Protozoa.

One obstacle experienced by all who have addressed them-
selves to the study of the soft part of the Rhizopoda, and
which has probably altogether deterred many from it, has arisen
from the difficulty of procuring those creatures in the living or
well preserved state. Professor Schultze mentions, as an en-
couragement to the study, that he found no difficulty in
bringing numbers of Polystomella strigilata, several Gromie,
Rotalia, and Miliolide, from Venice and Ancona to Griefs-
wald ; nor in keeping them alive for more than twelve months,
in as useful a condition for observation as on the first day.
He had, moreover, partially changed the sea-water but once
during the whole time. The water, however, contained living
Ulve. He has also found that specimens from abroad, pre-
served in spirits of wine, served extremely well for the purpose
of studying the soft parts.

Owing to the general similarity which exists apparently
throughout the rhizopodous class in the intimate structure of
the soft part, their systematic arrangement can only be founded
upon the shells, which exhibit an astonishing diversity of
form. Outof these forms it would appear, that the labours of
various naturalists in the last 100 years have made known
nearly 2,000 species of recent and fossil Foraminifera ; and
although the observations of Dr. Carpenter tend to show the
probability that very many of these supposed species are
merely varieties, still the number is sufficiently great to prove
the importance and interesting nature of the subject. Dr.
Schultze remarks upon the difficulties attending the study of
the Rhizopoda, and insists very properly upon the necessity
of viewing them in all positions, and under different modes of
illumination and of preparation, in order to arrive at a due
conception of their conformation.

The work commences with a copious literature of the sub-
ject, and then, after a short historical introduction, pro-
ceeds to general considerations on the structure and vital
phenomena of the Rhizopoda, commencing with a description
of the hard part, or shell, followed by that of the soft tissue
contained therein. An account is then given of their nutrition,
reproduction (confessedly imperfect), and growth; to which
succeed observations on the nature of the Polythalamia, as

DR. SCHULTZE, ON THE RHIZOPODA. 145

individuals or as colonies, and on the occurrence and the col-
lecting of living marine Rhizopoda.

To this part of the work are added remarks upon the classi-
fication of the Rhizopoda, including a tabulated view of the
families and genera, and the description, with beautiful
figures, of the species observed by the author in the living
state, of which we subjoin a list :—

Gromia. Rotalia. Textilaria.
Lagynis. Rosalina. Polystomella.
Squamulina. Polymorphina, Acervulina.
Miliola.

Dr. Schultze commences his description of the structure
and vital phenomena of the Rhizopoda by referring to the
well-known protozoon Ameba, Ehr. (Proteus, O. Miiller) ;
which may be thus briefly described :—Its body consists of a
transparent, colourless, contractile substance, whose individual
life is manifested by various changes of form, bearing the
character of voluntary movement. ‘This contractile substance
has the property of throwing out from any part of it a
rounded or pointed, longer or shorter process, in consequence
of which this simplest of animal forms presents the utmost
diversity of shape. No distinction can be perceived of mem-
brane and contents, and no cilia are ever observable. The
utmost powers of the microscope disclose merely a homo-
geneous, occasionally fine-granular, transparent (protein-) sub-
stance, with irregularly scattered molecular granules, with
sharp contours and of strongly refractive properties, imbedded
in it, together with some larger, clear, pale vesicles. The
former are either fat-drops, soluble in ether, or corpuscles,
soluble in a solution of caustic potass, but not so in ether or
acetic acid ; and the latter often resemble simple vacuities in
the substance, having no walls and filled with a homogeneous
fluid. The homogeneous matrix, as well as the imbedded
granules and ‘ vacuoles”—as the cavities above described
have been termed—are in a continual kind of flowing motion.
The substance appears to be throughout equally capable of
movement and equally sensitive; and any part of it appears
also to be equally capable of assuming the function of a mouth
or vent.*

In the Adriatic Sea, Dr. Schultze met with an Ameba,
differing from the known species belonging to fresh and salt
water by the extraordinary extensibility and active motion of
the contractile substance of the body. He terms this species

* Vide Description of Actinophrys Sol, by Kolliker, in ‘ Quarterly
Journal of Microscopical Science,’ Vol. i., p. 25; and Siebold’s Observa-
tions on Unicellular Plants and Animals. (Ib., p. 111.)

VOL. III. L

146 DR. SCHULTZE, ON THE RHIZOPODA.

A. porrecta, and gives a figure of it (Plate VIII. fig. 18). In
this form filamentary processes are sent out from all parts of
the colourless body. These processes are of some width at
their commencement, and soon subdivide into branches. Their
length is sometimes eight or ten times that of the body, and
they ultimately become so fine that their terminations can
only be distinctly seen with a magnifying power of 400
diameters. The form and extension of the body changes
every moment, according as the diffluent substance is thrown
out into these processes. If two of the processes come in
contact with each other they coalesce, forming broadish plates
or reticular meshes, which, the change of figure never ceasing,
are either retracted into the common mass of the body or are
enlarged by additional protrusion of its substance. A con-
tinued current of the granules imbedded in the contractile
substance accompanies all these phenomena ; and in the pro-
cesses this current follows two directions. On one side the
globules may be seen advancing towards the end of the pro-
cess, where they turn round, and are carried with a compara-
tively more rapid motion again towards the base of the fila-
ment, where they are lost in the substance of the body, unless
they may happen to meet another stream, by which they are
reconveyed through the same circuit.*

This creature, which resembles in many respects, as will at
once be obvious, the well-known Actinophrys, may be taken
to represent the type of the Rhizopoda ; and the soft part, or
animal as it may be termed, of all the numerous forms in-
cluded in this class, is constituted in accordance with it. The
only essential difference, so far as is at present known, con-
sists in the nature and form of the more or less hard test or
shell. Where this test exists, it follows, as a matter of course,
that the body itself of the animal cannot change its form, but
the shell is always furnished with an opening, or with open-
ings, through which motile processes, exactly like those above
described, are protruded and moved. Thus, in the Arcelle
and Difflugie, abounding in fresh water, finger-shaped pro-

* The same apparent circulation of granules is observable in the reti-
cular filaments in the body of Noctiluca miliaris, first pointed out by M.
de Quatrefages ; but the reality of which, in the uninjured condition of.
the animal, Mr. Huxley (‘ Quarterly Journal of Microscopical Science,’
Vol. iii., p. 51) seems inclined to dispute. Our own observations, how-
ever (though not very numerous), would lead us to imagine that M. de
Quatrefages’ account is correct. If so, the remarkable similarity of the
movement in those filaments in Noctiluca with that observed in the
Rhizopods should not be lost sight of, nor the apparent correspondence of
the motions of the particles in or on them, with that which may be wit-

nessed in the nuclear currents, or mucous strings, in the cyc/os’s in certain
vegetable cells ; as, for stance, in the hairs of Tradescantia.

DR. SCHULTZE, ON THE RHIZOPODA. 147

cesses are protruded through a large opening in the mem-
branous, chitinous test. In Arcella this test is soft and
flexible, and in Difflugia it is impregnated with silex (in the
form of arenaceous particles, Diatomacee); whilst in other
forms, apparently living only in the sea, the body is enclosed
in a calcareous shell, though the filamentary processes exhibit
exactly the same phenomena as those described in Ameba
porrecta. ‘These filaments are protruded either from a single
large or from numerous minute openings, and are characterised
by the active stream of minute globules. Their length is occa-
sionally twelve times the diameter of the body; they branch
repeatedly in their course, and are united by delicate bridges
and plates. The network of sarcode-substance thus produced
not unfrequently covers an area of several lines in diameter, in
the midst of which is seated the body of the animal enclosed in
its saccular flexible test, or in a delicate chambered shell,
like a spider in the centre of its web. These forms constitute
the testaceous Rhizopoda, and are the subject of the present
work. On account of their nautilus-like and chambered shell,
they were formerly arranged with the Cephalopoda, but were
placed in a distinct class by D’Orbigny, under the name of
Foraminifera. From Breyn (1732) and Soldani (1789-98)
they received the name of Polythalamia, under which desig-
nation they were described by Ehrenberg as a sub-order of
the Bryozoa. But neither of these appellations, strictly inter-
preted, is applicable to the entire protozoan class of Rhizo-
poda; inasmuch as they are unsuitable to the naked forms,
which, as we have seen, must be included in that class.
Either, however, might be used to designate that subdivision
of the class in which the soft animal is included, in a fora-
minated or chambered shell.

Owing to the opacity of the shell in many of the Forami-
nifera, and the strong refractive power of the earthy con-
stituent, it is but rarely that satisfactory observations have
been possible in uninjured individuals. It is requisite, there-
fore, either by breaking the shell, or, what is better, by the
careful removal of separate portions of it, to expose the body
of the animal. And the same end may also be attained by
the careful application of diluted acid. By these three
methods it is not difficult to obtain a satisfactory view. It
need scarcely be remarked, that the parts external to the shell
can be observed without any extraneous aids of the above
kind, and that the observation should be made in the living
creature.

The shell with which the soft substance is closely invested
is either flexible, or rigid, being rendered so by the deposition

ED

148 DR. SCHULTZE, ON THE RHIZOPODA.

of calcareous salts. The only two marine genera in which the
shell is flexible are Gromia and Lagynis, in which it would
seem to resemble that of Arcella, Euglypha, and Trinema. In
chemical constitution it approaches chitin. The flexible shell
of these genera and of their fresh-water allies have but one
opening, and are not furnished with the minute pores which
are found so generally in the calcareous-shelled Rhizopods.
All the other Foraminifera are characterised by having a rigid
calcareous shell; though there seems to be, at any rate, one
exception to this, in a new species described by Dr. Schultze,
under the name of Polymorphina silicea, in which the shell is
constituted of minute granules and angular tables of szlex, and
which might, therefore, be compared with that of Difflugia.

When recent Foraminifera are dissolved in dilute acid, an
organic basis is always left after the removal of the calcareous
matter, accurately retaining the form of the shell, with all its
openings and pores. The earthy constituent is mainly car-
bonate of lime ; but Dr. Schultze has satisfied himself of the
presence of a minute amount of phosphate of lime in the
shells of recent Orbiculina adunca from the Antilles, and of
Polystomella strigilata from the Adriatic.

As respects the intimate structure of the shell, the calca-
reous Foraminifera may be arranged in two series; in one of
which the shell is perforated by numerous minute openings or
canals, and in the other appears to be solid and homogeneous.
In the latter the animal communicates with the external world,
either through a single large opening, or, instead of that, there
may be several smaller openings grouped together.

Dr. Schultze has never been able to detect any trace of an
organic envelope on the surface of the shell, as described by
Carter in Operculina arabica.

The chambers of the shell communicate by similar pores
and canals through the dissepiments ; but of the “ interseptal
spaces” described by Carter in Operculina arabica, and by
Williamson in a species of Faujasina (neither of which forms
had come under his observation), Dr. Schultze has never
seen any appearance in other Polythalamia belonging to nu-
merous genera,

With respect to the classification of the Polythalamia, Dr.
Schultze takes the mode of disposition of the chambers as the
basis of his arrangement, Three principal types are in this
way afforded, according as the chambers are disposed in a
straight (or slightly curved) line; or in a spiral direction ; or
in confused heaps. The first corresponding with the Stichoste-
giens of D’Orbigny; the second with his Stelicostegiens,
Entomostegiens, Erallostegiens, and Agathistegiens ; and the

DR. SCHULTZE, ON THE RHIZOPODA. 149

third including a small number of species hitherto over-
looked, and united by Dr. Schultze in the genus Acervulina.
In Dr. Schultze’s arrangement these three divisions constitute
as many groups, under the names of Ruasporwea, HELIcorDEA,
and SoroIpEA.

The Monothalamia he subdivides into three families. The
first embracing all the forms having a sacciform, solid, cal-
careous, or membranous test, with a single large opening.
The second is constituted of the single genus Orbulina, D’ Orb.
(Mitiola, Ehr.), and is distinguished from the preceding by
the globose, calcareous test, having no large opening, and per-
forated all round by fine pores. The third family, lastly, in-
cludes the genus Cornuspira (Schultze), having a monothala-
mous, calcareous shell, convoluted like that of a Planorbis,
and furnished with a large opening.

The following tabular arrangement of the Rhizopoda is given
by Dr. Schultze, with which we must conclude this notice
of his most valuable work.

RHIZOPODA.

A. NUDA.
Gen. Ameba (Noctiluca ?)

B. TESTACEA.

I. MonoTHALAMIA.
Test one-chambered ; animal undivided.

1. Fam. Lacynipa.—A sacciform, calcareous, or membranous, non-porous
test, with a large opening.
Gen. Arcella, Difflugia, Trinema, Kuglypha, Gromia, Lagynis,
Ovulina, Fissurina, Squamulina, &c.

2. Fam. OrpuLisipa.—A globose, calcareous test, without a large open-
ing, and finely porous throughout.
Gen. Orbulina.

3. Fam. CornuspiripaA.—A calcareous test, convoluted like the shell of a
Planorbis, with a large opening.
Gen. Cornuspira.

II. PoLyYTHALAMIA.

Shell polythalamous ; the animal constituted of segments, connected by
slender processes.

1. Group HELIcomDEa.
The chambers disposed in a spiral.

4, Fam, Minioripa.—Each chamber occupies a half-spiral ; the spires
developed either in one plane or in various planes.
The shell has only one large opening at the
extremity of the last spiral. No pores.
Gen. Uniloculina, Biloculina, Miliola, Spiroloculina, Articu-
lina, Spheroidina, Adelosina, Fabularia.

150 DR. SCHULTZE, ON THE RHIZOPODA.

5. Fam. Turpinorpa.—The spiral formed by the chambers resembles

1. Subfam.

Gen

2. Subfam.

that of the shell of Helix or Turbo. The spiral
is only visible on one side of the shell. Some
are so much drawn out that the chambers are
disposed alternately, as it were, in two con-
tiguous rows. The shell has a large opening
in the last chamber, and the surface is almost
always finely perforate.

Rotalida.—Shell depressed or conical ; chambers not

embracing each other; shell glassy, trans-
parent; finely perforate.

. Rotalia, Rosalina, Truncatulina, Anomalina, Planorbu-
lina, &e.
Uvellida.—Shell in the form of a longer or shorter raceme.

The chambers frequently almost completely
embracing. Shell usually thick and coarsely
perforate, or solid.

Gen, Globigerina, Bulimina, Uvigerina, Guttulina, Candeina,

3. Subfam.

Globulina, Chrysalidina, Pyrulina, Clavulina, Poly-
morphina, &c.
Textilarida.—Spire so much produced that the chambers

lie alternately in two contiguous rows.

Gen. Gaudryna, Textilaria, Virgulina, Vulvulina, Sagrina,

4. Subfam.

Bigenerina, &c.
Cassidulinida.—Textilaridans, curved once in a direction

perpendicular to the original spiral.

Gen. Ehrenbergina, Cassidulina.
6. Fam. Nautitorpa.—The spiral formed by the chambers has a general

resemblance to the shell of an Ammonite or
Nautilus. The spire is visible on each side of
the shell, or not visible on either side. The
anterior wall of the last chamber is furnished
with one larger or several smaller openings ;
the remainder of the shell is usually finely
perforate.

1. Subfam. Cristellarida.—Shell thick, finely perforate, colourless,

transparent ; chambers embracing, with
a large opening at the upper angle of
the anterior wall of the last chamber,
to which the communicating openings
between the separate chambers corre-
spond in position.

Gen. Cristellaria, Rotalina, Marginulina, Flabellina.
2. Subfam. Nonionida.—Shell thick or thin, colourless, transparent,

finely perforate ; chambers either em-
bracing or not. ‘The opening in the
anterior wall of the first chamber at the
side looking towards the penultimate
spiral; the communicating openings of
the separate chambers in the correspond-
ing position.

Gen. Nonionina, Haverina, Orbignyna, Fusulina, Nummulina,

Assilina, Siderolina, Amphistegina, &c.

3. Subfam. Peneroplida.—Usually thin, always brown, transparent

shells, with or without fine pores; the

DR. SCHULTZE, ON THE RHIZOPODA. iy |

chambers very narrow, embracing or
not. Numerous openings, scattered over
the whole of the anterior wall of the
last chamber; or, instead of these, a
large opening produced by the coales-
cence of numerous smaller ones.

Gen. Peneroplis, Dendritina, Vertebralina, Coscinospira, Spi-

rolina, Lituola, Orbiculina.

4. Subfam. Polystomellida.—Shell tolerably thick, colourless, trans-
parent, finely porous ; chambers em-
bracing ; the anterior wall of the
last chamber, besides the fine pores,
has either no larger opening at all, or
a few very minute, irregular fissures,
on the side towards the penultimate
whorl. On the surface of all the
chambers, rows of fissure-like, often
perforating depressions, running at
right angles to the direction of the
dissepiment.

Gen. Polystomella.

7. Fam, ALVEOLINIDA.—Globose, ovoid, or cucumber-shaped shells, com-
posed of spiral tubes, each resembling a Cor-
nuspira, and furnished with a special open-
ing at the end of the whorl. The tubes all
communicate by connecting openings, and
besides this, are all subdivided by incomplete
dissepiments, in the same manner as in the
Nonionina. The situation of these dissepi-
ments, which are but few in number, and of
the connecting openings, is indicated by me-
ridional lines, which are seen on the surface
of the shell.

Gen. Alveolina.

8. Fam. Sorrrmpa.—Discoid, multicellular shells, exhibiting only in the
centre an indication of a helicoid spiral, otherwise
cycloid ; that is, growing uniformly at the whole
border of the disc. The brown, transparent,
finely porous shell, is formed of minute chambers,
connected together in the direction of straight or
curved radii, and at the border of the disc, each
presenting a large opening.

Gen. Sorites, Amphisorus, Orbitulites (Orbitoides, Orbitulina,
Phaculina, Marginopora), Cyclolina (chambers _per-
fectly annular, with numerous openings on the border
of the disc).

2. Group RHABDOIDEA,

The chambers arching one over the other, in a straight or slightly curved
line, in a single series,

9. Fam. NoposaripA.—Rod-shaped shells, whose chambers are super-
imposed one upon another in a series, and
communicate with each other by a large open-
ing; a similar opening in the last chamber.
(Except in the genus Conulina, where there

152 DR. KEBER, ON THE POROSITY OF BODIES.

are numerous openings instead.) The shell
usually thick, perhaps always perforated by
fine pore-canals.

Gen. Glandulina, Nodosaria, Orthocerina, Dentalina, Frondi-
cularia, Lingulina, Rimulina, Vaginulina, Webbina,
Conulina.

3. Group SoROIDEA.
Chambers grouped in irregular masses.

10. Fam, AcERVULINIDA.—Chambers usually globose, disposed very irre-
cularly one upon another, and of pretty
uniform dimensions ; shell finely perforate,
and with a few larger openings at indeter-
minate places.

Gen. Acervulina.

MIKroskoPIscHE UNTERSUCHUNGEN UEBER DIE PorosITaT DER KORPER.
Nebst &c. F. Keper. (Microscopical Researches on the Porosity of
Bodies. Together with a Memoir on the entrance of the Spermatic
Cells into the Ovum. By F. Keber.)

WE shall, on the present occasion, confine our remarks to the
former of the subjects treated on by Dr. Keber, an abstract
of whose Memoir on the Porosity of Bodies, furnished by the
Author and translated by Dr. Barry, appears in the ‘ Philoso-
phical Magazine’ for October and November, 1854. Dr.
Barry has also appended to it what he terms ‘ Confirmations’
of Dr. Keber’s views.

Dr. Keber states, that after many fruitless attempts, he has
been so fortunate as to discover in the substance of all
organic bodies already formed (though what that means is
not very obvious), microscopic spaces from 1-12000th to
1-48000th of an inch in diameter ; and generally, in all bodies
which he has examined, to recognize signs of an optically de-
monstrable and measurable microscopic porosity.

It must be understood, however, before going further,
that this porosity is not to be confounded with the spaces
between the fibres or other constituent elements of organic
tissues. The porosity of Dr. Keber is of a much finer kind
than this, and is to be sought for in the substance of which
the fibres, &c., themselves are composed. 'To observe sucha
condition as this, it is obviously requisite that the substance
to be examined should be divided into infinitely small por-
tions. Several methods of proceeding are indicated by which
particles sufficiently small may be obtained for examination.

1. A very successful method, according to Dr. Keber,
consists in the examination of the dusty particles which settle
upon glass when left uncovered ; though this mode would

DR. KEBER, ON THE POROSITY OF BODIES. 153

seem to be open to the objection that the observer cannot
possibly tell what he is looking at.

2. The surface of the body to be examined may be scraped
very gently with a knife.

3. As some bodies are too hard for this purpose, the minute
particles required are procured by the attrition of two por-
tions of the same substance against each other.

4. The particles may be procured simply by gentle but
continued tappings upon the glass with the body to be ex-
amined. ‘This method, it is true, the author observes,
‘takes more time than the others, but is very sure and easy of
application.’

5. With bodies that are fresh, and still moist, the mode of
proceeding consists in passing the knife most gently over their
surface, and laying the detritus upon glass, which must be
examined without the addition of water, and without a
covering of glass. And it is to be observed that the particles
of dry substances are also to be examined in the dry state, but
that they should be covered with thin glass.

Among the organic and inorganic bodies examined in this
way by Dr. Keber, he mentions :—

The shell and membranes of the egg; the epidermis and
cutis of man and many animals; horny substances ; hair; the
cell-membrane ; the mucous and vascular membranes ; the
walls of capillaries, lymphatics, blood-corpuscles ; serous
membranes, ligaments, bones and teeth. All parts of plants,
and most definitely in the roots! Charcoal, pitcoal, and brown
coal; gold, tin, silver, lead, iron, granite, many crystals,
&c. ‘The pores of granite (which constituent ?) measure in
diameter 1-14400th inch; those of iron, 1-24000th to
1-36000th inch; those of steel, which however are very
difficult of demonstration, appear to be still smaller. The
average size of the pores in all vegetable formations may be
taken at 1-18000th inch, among which there occur individual
variations of from 1-12000th to 1-24000th inch. The pores in
animal formations are about the same _ size as those of
plants. In the membranes of the ovum of man and the rabbit
they measure 1-14400th to 1-19200th inch, and the same in
the human cuticle and skin.

The evidence upon which Dr. Keber relies in support of
his assertion of the existence of pores of the above kind in all
bodies, is this: that in the most minute particles of any kind
he perceived, on close examination, what he supposes to be
exceedingly minute spaces and clefts, varying in diameter
from 1-14000th to 1-18000th inch, the colour of which, but
principally with bright illumination, mostly exhibited a

154 DR. KEBER, ON THE POROSITY OF BODIES.

reddish or greenish tinge. Upon long examination he also
noticed that the borders of the dust-particles, as well as their
finer indentations and inlets, frequently presented exactly the
same reddish and greenish edges. This accordance in the
colouring of the borders, with that of the apparent spaces in
the substance of the dust-particles, could not, in the Author’s
opinion, do otherwise than serve as a confirmation of his belief
that he had before him real spaces and minute orifices. More-
over, with the alternate elevation and lowering of the object,
and with alternately increased and diminished illumination, he
distinctly saw the light flash through them. To the above, which
really includes the whole of Dr. Keber’s discoveries, we would
merely add that his observations were usually made with a
magnifying power of 200 diameters and with an aplanatic
eyepiece, and with full transmitted light. With this power he
was able to perceive in all bodies whatsoever examined by
him—including metals, minerals, &c.—the following parti-
culars: 1. As it would seem, that they are composed of
scales, all of which are constituted of a delicate net-and-
lattice-work of variously interlaced fibres, with lamelle more
or less covering one another, which however, partly between
them, partly in their substance itself, present a multitude of
minute, irregularly-shaped roundish, elongated, indented and
angular orifices, spaces or rifts which are sometimes dendriti-
cally branched, and form a system of communicating hollow
interstices or passages. All to be seen and measured with a
linear magnifying power of 200 diameters, and with an object-
glass, by Dr. Keber’s confession, very far from corrected for
chromatic aberration ; as we have reason to believe is the case
with many object-glasses used by German observers !

The absurdity of these assertions, and of the pretended
discoveries of Dr. Keber, will be so glaringly manifest to any
one who has had the slightest experience with the microscope,
that we should not have occupied a page of the Journal with
them had it not been for their appearance in a periodical of
such high scientific repute as the ‘ Philosophical Magazine,’
and under the auspices of one who, with all his obstinacy in
the retention of exploded views, deserves the greatest respect
from every physiologist and microscopical observer. We are
sorry to say, however, that Dr. Barry’s reputation as an
observer will not be enhanced by his fostering of Dr. Keber’s
extravagant notions; nor do we perceive either that that
imaginative microscopist has much to thank Dr, Barry for,
in- what the latter terms his ‘ Confirmations’ of the dis-
coveries. For, according to the ‘Confirmations,’ the German
observer’s pores are not pores at all, but the nucleoli of a flat

MANUAL OF PATHOLOGICAL ANATOMY. 155

or discoid nucleus, that has divided into many still adherent
parts, each part being itself a nucleus, and having its single
nucleolus. It would seem, therefore, that bodies are not porous
at all, but solid; and moreover, that gold, tin, silver, lead,
iron, granite, and many crystals, are composed of scales, each
of which is a flat or discoid nucleus, divided into many still
adherent parts, &c. !

Dr. Keber’s views on the porosity of bodies, and his mode of
demonstrating it, require nocomment. Any one, with a mode-
rately good object-glass, can of course at once satisfy himself of
their fallacy ; and we would merely request him, should he ever
see our pages, to notice that the old Florentine experiment
by no means proves the porosity of gold any more than does
the translucency of gold leaf, and that though the irregular
fragments of bodies which he has examined with a defective
instrument may exhibit the colours and appearances he
describes, and though some of them may present actual
openings of the size he mentions, it is absurd to deduce from
that that all bodies are pervaded by pores, in general not less
than 1-24000th of an inch in diameter, The mere inspection
of such an object as a scale of Pleurosigma angulatum, for
instance, in which dots of infinitely less size than that can be
seen and measured, and yet in which no pores of any kind are
perceptible, is sufficient to demonstrate that all bodies are not
necessarily porous. Dr. Keber should also remember that
although some stones may imbibe water when immersed in it,
all do not do so any more than do metals ; though according to
him all are equally furnished with pores and passages of pretty
nearly uniform size.

A Manvat or ParnonogicAL ANATOMY. By C. HaANnpFI£LD JoNEs,
M.D., and Epwarp H. Stevexina, M.D. London. Churchill.

Tuts will be a very acceptable volume to the medical pro-
fession, because we have no work embracing, in a compressed
form, the results of recent researches in the science of
pathology. Within a few years, also, the character of much
of our pathological anatomy has been rendered much more
accurate and comprehensive by the use of the microscope.
The authors had thus presented them a very wide field ; and if
we find defects in this volume, we must rather put it down to
the magnitude of the subject, and the necessity of bringing out
the work speedily, than to any want of industry and capability
onthe part of the authors. We have to thank them that they
have done so much. Although the whole work is a joint pro-

156 SHORT NOTICES.

duction, the authors have taken separately their various especial ~
parts of the work. Thus Dr. Jones has written the department
of General Pathological Anatomy with that of the Alimentary
Canal and other viscera; whilst Dr. Sieveking has given the
Pathology of the Nervous, Circulating, Respiratory and Osse-
ous systems. We think the work would be improved by extend-
ing the general department so as to make it embrace all patho-
logical conditions, without the necessity of repeating under the
head of each system much of what has been previously stated.
This would reduce the bulk of the special department, and give
the authors the opportunity of going into greater detail in their
account of microscopical pathological conditions. The chapter
on parasites, for instance, might thus be greatly extended,
especially the portion devoted to their vegetable forms, and
the results of such researches as those in Robin’s volume on
‘Vegetaux Parasites’ given.

The volume forms one of Mr. Churchill’s medical manuals,
and is illustrated with a large series of well-executed wood-
cuts,

A PopruLaR History or British Mossres. By Ropert M. Strack.
Reeve. London.

TuerE are few departments of vegetable anatomy that offer a
less trodden field for the microscope than the family of Mosses.
As yet we are very imperfectly acquainted with the history of
their development and the mode of their reproduction. They
afford an interest, not only on account of their present distri-
bution on the earth’s surface, but also on account of their
previous history in connection with the extinct vegetation
presented to us in the coal and other strata. This little book
does not profess to give an account of the microscopic struc-
ture of British mosses; but all those who are studying this
subject will find it of great assistance in furnishing the names
of particular mosses, and enabling them to identify their spe-
cimens. This work is one of the best of the series to which
it belongs, and is a very useful addition to the literature of
our native botany.

EruDEs PHYSIOLOGIQUES sUR LES ANIMALCULES DES INFUSIORES VEGE-
TATES. Par Paunt Laurent. Tomel, Nancy. 1854.

M. Laurent is known for his microscopical researches ; but,
unfortunately, the author has adopted theories which evidently
interfere with his power of making accurate researches. In
the first place, he maintains that there is no distinction be-

SHORT NOTICES. 157

tween the animal and yegetable kingdoms, and then proceeds
to demonstrate the fact by showing that infusory animalcules
are produced from the tissues of plants. His observations are
undoubtedly curious, but from his having a preconceived notion
to establish, they must all be taken with considerable caution.
One of the great objects of the work is to show that the ordi-
nary cells of the cellular tissue of plants become converted
into true infusory animalcules. Not only does M. Laurent
attempt to demonstrate this fact, but having thus procured
his animalcules, he proceeds to give a detailed history of their
habits and functions, very different, indeed, from any that
has hitherto appeared. The work is illustrated with twenty-
two quarto plates, giving coarse though graphic views of all
sorts of animalcules; but in these the experienced microsco-
pist will meet with many forms that are familiar enough in
ordinary vegetable infusions, whilst in others he will not fail
to observe the workings of an imagination bent on supporting
a particular view of the facts presented.

( 158 )

NOTES AND CORRESPONDENCE.

@n a mode of washing and concentrating Diatomaceous Earths
and Clays.—The following method which I have adopted, with
tolerable success, consists in making the deposits fall through
a constant depth of water, in various periods of time; thus
dividing the diatomes, according to their sizes, into portions
of several different gravities.

Rule.—Take about a cubic inch of the clay to be examined,
digest it for about four hours in strong nitric acid at a mode-
rate temperature ; now add gradually an equal quantity of
hydrochloric acid, effervescence takes place, a further action
on the clay ensues; keep boiling for about three hours more,
occasionally stirring, and then allow the mixture to cool and
settle down, which it will do in about an hour ; pour off the
superfluous acid and wash the residue repeatedly with water,
so as to get rid of the remaining acid.

The next operation is to divide the sediment into portions of
various specific gravities; for this purpose it is necessary to
have several beakers, about 3 or 4 inches in height, and about
14 to 2 inches in diameter; also one very large beaker, about 6 to
9 inches in diameter: we will call the large beaker A. Now
transfer the sediment into one of the small beakers, and pour
in water till there is just 2 inches depth of water in the glass.
Stir and let stand half-a-minute by the watch, and then pour
off carefully into the large beaker A ; repeat this about half-
a-dozen times, each time pouring off into A all that does not
fall through the 2 inches of water in the half-minute, and at
last the small beaker will contain only what falls through
2 inches of water in half-a-minute. Now let A stand about
half-an-hour, pour off carefully, and transfer the sediment in
A to another small beaker; put 2 inches of water with it,
stir and let stand for 2 minutes, then pour off into A. Re-
peat this about six times, and there will now be another small
beaker containing all that falls through 2 inches of water in

+ minutes; while in A is all that does nof fall through that
distance in that period. Let A stand half-an-hour, pour off
and transfer the sediment to another small beaker, stir and let
it stand five minutes, pour off into A as before, and repeat
this as before about six times. There is now another beaker,
containing all that falls through 2 inches of water in 5
minutes, After this I do not divide them any further, but

| MEMORANDA. 159

call the last remainder, or what remains in A after it has
stood its half-hour, ‘‘ Not in five minutes.” Thus we have
four different glasses, containing diatomes and clay mixed, of
four different densities: thus 0 to 4; 4 to 22; 22 to 53 not
in 5. There is now a method of concentrating the coarsest of
these sediments, namely, the 0 to 4, the to 24, and some-
times the 23 to 5. It consists in taking the beaker containing
the sediment and pouring about an inch of water on it. Let
it settle about 5 minutes and then place the glass on a table,
and impart a whirling motion to the whole by moving it
round and round, fier the greatest portion of the diatomes
will rise up in a sort of eddy, while the particles of mud or
sand will remain at the bottom, even though they are of the
same specific gravity as the diatomes, and have fallen through
the same distance of water in the same time. This is because
the diatomes are mostly flat and thin, while the particles of
sand and mud are round; in the same way, if we take a round
pebble and an oyster shell both of the same weight and throw
both horizontally into the water, the pebble will reach the
bottom sooner than the oyster shell. So when the whirling
motion is imparted to the glass, the thin flat shells of the
diatomes will rise up in a cloud, while the round particles of
mud and sand will remain behind ; when the cloud rises up,
pour it off quickly and dexterously into another glass, and, if
necessary, repeat the process, and a little practice will enable
the operator to separate all the diatomes most effectually. I
have said before that this process will only apply to the
0 to 4,3 to 24, and sometimes the 23 to 5 sediment, but not at
any finer one; practice may soon teach this. The “not in 5”
cannot be concentrated, it is too fine, and the whole rises
together on imparting the whirling motion to it.

It is not necessary to abide invariably by the divisions of
time which I have given here.

These must be varied, of course, according to the nature of
the clay to be examined. For instance, in a clay I have re-
cently tried from 34 feet below the bed of the river at Cardiff,
nearly the whole of what was left after the 0 to 4 fell in the
4 to 24. I, therefore, divided it thus: 0 to 3, 4 to 13, and
14 to 24; a little practice will soon teach this.

The advantages of the plan are, I think, obvious. In the
first or coarsest sediments we get all the larger and finer
Diatomes by themselves, unmixed with and consequently un-
obscured by the innumerable smaller ones, and the fine
particles of mud and sand; while if any of them, such as the
Eupodisci or Campylodisci are rare, they are sure to be found
in either the first or second division of densities, and by their

zr
ah
2

160 MEMORANDA.

being concentrated and brought as it were into a small com-
pass the detection of them is easy and certain.

In the next division, or the 23 to 5, we shall find the
moderate-sized diatomes ; and lastly, in the “not in 5,” we
get a mass of the remaining and smaller diatomes, all of
which small ones are themselves the more readily seen and
identified when separated from their larger brethren.

I would venture to add, moreover, that I think the exami-
nation of these deposits for the various species is much faci-
litated, as the slides containing the 0 to 14 sediment may be
examined with the inch objective; the + inch will do to
examine the 1} to 24, and 24 to 5; while the } inch need
not be used till we come to the ‘not in 5,” whereas were
they all mixed the 4 inch would be required to examine the
whole.

I should add, that what is poured off the large beaker A,
after it has stood the half-hour each time, may be flung away
and the sediment only transferred to the small beakers, as
from the large size of it there will rarely be more than
2 inches depth of water in it, and half-an-hour is ample time
to ensure every diatomaceous particle atom falling to the
bottom and being preserved and detected in one or the other
of the divisions.—F. OxkepEn, C.E.

Aperture of Object-glasses.— As my friend Mr. Sollitt consi-
ders the principle that I have proposed, for measuring the
angle of aperture of object-glasses, is both complex and
erroneous, I may briefly remark, that he himself supports me,
with the most substantial evidence possible, of his own per-
fect conviction of its utility. Simply, because the very
method that he has proposed as a substitute, both in its
action and use, is absolutely identical with my own; which
is, “‘ to use the object-glass of the microscope as the objective
of a diminishing telescope.” ‘This I accomplished by placing
a biconvex lens over the eye-piece.

The next point in question is, with respect to the angle of
aperture being reduced upon an object, immersed in balsam ;
wherein Mr. Sollitt is of opinion, that both the results of
Professor Robinson and myself are erroneous.

The methods of measuring apertures under the latter con-
ditions must, of necessity, be altogether different, and form a
distinct branch: at present I know of no principle that will
serve the purpose so well as that proposed by Professor
Robinson. The experiments that Mr. Sollitt has brought
forward to prove that it is an error to suppose, that the angle
of aperture is reduced in balsam, amounts to no proof at all,

MEMORANDA. 161

merely because they form no representative of the conditions
of an object, mounted in the substance of a refracting medium.

Mr. Sollitt.imagines that the theory, as I have explained it,
is tantamount to this,—that when a parallel plate of a refract-
ing body is interposed between the object-glass to be mea-
sured and the candle, it should reduce the aperture. How
he could interpret my meaning thus I am at a loss to conjec-
ture, when I stated distinctly, in my paper in the ‘ Micro-
scopical Journal,’ page 213 :—‘* That a parallel plate of glass,
over an object mounted dry, has no effect in reducing the
aperture, for the rays, after being deflected by the first sur-
face, emerge again from the second one, parallel to their
original direction, and all converge to a point, at the same
angle as at first ; consequently, the object is seen through the
glass, with an angle of aperture the same as if it was not
interposed.” ‘I'his is also the case, if several parallel plates
of substances of different refractive powers be interposed.

That the candles which Mr. Sollitt made use of exactly
represented objects mounted dry, there can be no question ;
and his results are as they should be, But if each candle
had been a body contained in the substance of a solid block
of glass, extending from the object-glass; then a very different
indication, or a diminished aperture, would have been ob-
tained.

I imagined that my explanation would have been very
easily understood, considering that it strictly depended upon
the first law of refraction, contained in any elementary work
upon optics. The annexed cut may serve as a particular
illustration of the method of measuring the loss of aperture
on objects in transparent media. In diagram 1, let aa repre-
sent a parallel plate of glass, or other medium, Suppose an
object to be immersed just within its substance at 6, to be
viewed with an object-glass, whose aperture is cc. Now,
according to the laws of refraction, the aperture, or angle of
rays, collected from the object must be represented by the
lines taken from } to the points of incidence of the exterior
rays of the object-glass, at the upper surface of aa. This is
the theoretical explanation of the loss of aperture on an object
thus mounted.

The practical method of obtaining the actual measurement
of the refracted and reduced angle of aperture is demonstrated
by diagram 2. Let cc again represent the aperture of the
object-glass, which is focussed exactly on to the upper surface
of aa; the rays, cc, will be refracted to dd, forming an angle
exactly similar to that at diagram 1, but inverted. It is
therefore evident, that if we measure the base or diameter

VOL. III. M

162 MEMORANDA.

of the cone of light, at the under surface at dd, the apex
being taken from the upper side of aa, it will truly represent
the loss of aperture caused by the first refraction of the one
surface of the medium.

we.

The section of the cone of light at dd may be rendered
visible by breathing on the under surface of aa; but for
accuracy | have used a thin film of bees’-wax, as this allows
the diameter to be marked with a needle-point with great
nicety.

In giving this additional explanation I do not, in the
remotest degree, intend to insinuate, that Mr. Sollitt is not
perfectly familiar with the theoretical facts upon which this
method of measuring apertures is based; but I entirely blame
the want of perspicuity, which prevented me from making
myself understood in the first instance.

There is a remark contained in my paper, which subsequent
observation has induced me to recall, or at least to modify,
the very general interpretation to which it is liable. The
expression that I allude to was this:—‘‘I have invariably
found, that when very difficult tests are mounted in balsam I
cannot discover the markings.” In contradiction to this, I have
lately succeeded, in many instances, in bringing out the striz
on some, of what may be termed very difficult tests when in
balsam; but I do not see that this is to overturn the fact, that
we are actually seeing such objects with a diminished aper-
ture. But, however, the subject requires an investigation
that I have not yet had time to devote to it. I have thought
this notice due from me, as I asserted that the statement made
by Professor Bailey, of his employing no other than balsam
mounted tests, required some further explanation I may here
mention, that it is my opinion, that if an aperture of 125° is
reduced to 71° on an object in balsam, it will still have a

MEMORANDA. 1638

great advantage over a clear aperture of 71° on the same
object mounted dry ; because, if it is really as I have stated,
that the visibility of the markings depends upon their opacity,
we shall, in the former case, not only obtain more light
through the object itself, but there will also be no appreciable
loss from the reflection of the containing glass surfaces, as
there is in a dry mounting.

To those who may still doubt the question of the loss of
aperture, on objects immersed in refractive media, I will
recommend a trial of the following simple and instructive
experiment, bearing reference to the point in question.

Spread some moistened Diatomacee on a glass slip, and
when dry cover the deposit with a piece of thin glass; place
the slide under the microscope, and with an eighth object-
glass, select a specimen that may be considered as a test,
adjust and focus carefully, and so let it remain. Next, take
a drop of oil, or thin Canada balsam, at the end of a wire,
and drop it on to the edge of the thin glass cover. If the slide
is warm this will rapidly insinuate itself between the glasses,
Look through the microscope, and wait for its passage across
the field of view; directly that it has passed, it will be found
that everything that was visible on the slide, the moment
before, has vanished from sight; because the oil, or balsam,
has caused a different refraction of the rays from the object-
glass, the focus of which has, in fact, become lengthened ;
for, in order to bring the object again into view, the objective
must be brought back a farther distance from the test ; it will
then be found, if this was at all difficult, that the striew are
now totally invisible, under the same conditions of light, and
it will require a different arrangement of illumination to bring
them out again, together with an alteration in the adjustment
of the object-glass. It may be supposed that these effects are
analogous to those which would be produced by the interpo-
sition of an extra thickness of glass; but just the same phe-
nomena are observed if the objects are adherent to the thin
cover itself,

With this example I conclude my remarks, I consider
that the main point, that balsam or fluid mounting does
create a diminished aperture, still remains an untouched fact.

The inquiry is one of considerable interest ; and, as it may
end in an application of much utility, should be prosecuted
farther.— F. H. Wenuam.

On the Measurement of the Aperture of Objectives;— [ny your
last number I see that Mr. Sollitt proposes a new method
for measuring the apertures of objectives, in discussing which

mM 2

164 MEMORANDA.

he controverts some opinions expressed by Mr. Wenham
and me. On both these I wish to make a few remarks. _

I have stated in the paper to which Mr. Sollitt refers that if
rays nearly parallel be sent through the eye-piece of a micro-
scope down its axis, their extreme divergence, after passing
through the objective, will equal its angle of aperture, which
therefore is correctly ascertained by measuring that divergence.
The only methods, as far as I know, which do this are the two
which | have proposed,* all others depending on the dis-
appearance of a light seen obliquely. Of these Mr. Lister’s
(Mr. Wenham’s, Se similar, I have not tried) is alone
correct in principle, but it fails practically in extreme cases.
In Mr. Sollitt’s, and all of the same type, the process is by no
means so certain ; on the contrary, they are liable to two serious
objections: firstly, that when a pencil of light is inclined at a
considerable angle to the axis of an objective, its ultimate
angle of divergence is less than the aperture ; and secondly,
that this angle is not bisected by the ray which is parallel to
the original “direction, These are obvious from the theory of
oblique pencils, and it follows, as a necessary consequence,
that we thus measure, not the true aperture, but twice an angle
which is greater than the half of an angle which is less than the
aperture. Up to 45° there is no difficulty in seeing that these
two errors nearly compensate each other; but it would be no
easy problem to determine their effect at 80° or 85°. To this
I may add, that in Mr. Sollitt’s method he obtains not the
aperture of the objective which he tries, but the sum of it, and
that of the lens which he uses as an eye-piece,

I expressed a belief that objectives of large apertures receive
less light from an object in balsam than from one which is dry,
and 1 do not see how it can be avoided without also denying
the elementary principles of optics. A valve of a diatome
(for example) in air disperses light in every direction, as is
proved by illuminating it in a dark room with a narrow pencil
of sunlight transmitted perpendicularly through it. It is
perfectly seen out of the direct beam till its markings disappear
by foreshortening, but continues brilliantly visible till the eye
comes almost to the very plane of the glass on which it is
placed. Now, of this light, so dispersed, all (except what is
lost by the reflection of the cover) can come through it to the

* In measuring an objective of 176°, made by Spence, for my friend,
T. F. Bergin, Esq., the diameter of the cone’s section was so great that
I was obliged to modify the method, by receiving the light on a screen
made to travel in a cylindric surface concentric with the focal point,
This is a decided improvement, but requires the use of a graduated circle.
The result must, of course, be corrected for penumbra, &c.

MEMORANDA. 165

objective, even with 180° of divergence. In balsam there
must be the same dispersion of light; but beyond a certain
obliquity, it cannot emerge. ‘The refractive index of Canada
balsam is | 540, and that of such flint glass as I use for
covers 1*550; with these Mr. Sollitt will find that the limit is
40° 30' from the perpendicular, and that below this all the
rays must be reflected back and be absorbed or escape at the
edges of the slide. How much is thus lost cannot be assigned
without knowing how the intensity of this dispersed light
varies at different obliquities; but if it be uniform, then the
balsam unquestionably cuts off a portion of it whose quantity
is measured by the difference between a hemisphere and a
segment whose amplitude is 81°, or 0:76 of the whole. In
air the light will pass almost to 90°.

The first argument by which Mr. Sollitt endeavours to
overthrow this inference is, that he finds his measures of
aperture the same, whether he interposes in the course of the
light a plain slide or one with balsam. This must be the
case ; for every one knows that a ray incident on any system
of media, bounded by parallel surfaces, emerges parallel to its
original direction,* ‘But though it will pass the media, even
up to 90°, its course in themis always within the angle of total
reflection, and the light whose loss I have described comes not
by direct transmission, but by dispersion. How that disper-
sion is produced I do not now inquire ; but its existence is a
fact.

His second argument is, that test objects are as well seen in
balsam as when dry. This is not in accordance with my
experience, and I believe is not generally admitted. It is
true that a body of irregular surface and high refractive power
is (especially as to its internal structure) best seen in balsam ;
but this is a special case, and does not apply to one which,
like the valve of a Pleurosigma, is thin and flat. Indeed,
besides the point in question, this medium may be expected
to injure vision by weakening the dispersion and reflection of
the light. The refractive index is nearly that of quartz for the
ordinary ray, which is probably the same as that of silica, as it
exists in these valves, having no active or polarized light sf at
it were exactly the same, neither the valve nor its markings
could be seen at all, and as it is, its action makes the latter

* It is shifted a little sideways, which is the reason that we can use
these large apertures with covers of a certain thickness, but this can
make no change in the measure.

+ In this respect they contrast strongly with undoubted vegetable pro-
ductions, such as the siliceous integuments of grasses and Equiseta, the
hairs of Deutzia, &c.

166 MEMORANDA,

finer and fainter. If Mr. Sollitt will repeat one of my ex-
periments, select a single valve, whose details are barely
visible when dry (the objective may be of moderate aperture },
successively introduce under its cover, water, alcohol, and
balsam, and use very deep eye-pieces, which are the sure tests
of deficient light, he will probably find reason to change his
present opinion as to the effect of dense media.

It may be of use to some of your readers to know that I have
ascertained the nature of the irregularity which injured
the circumference of the objective described in my paper as
No. 4. (Quarterly Journal of Microscopical Science, vol. 11.
p- 296.) I sent it to a distinguished optician, Mr. Grubb, of
Dublin, to have a graduation put to its compensation, who, on
taking it asunder, found that a little of the cement which
unites the lenses was visible round the edge of one: this he
very cautiously removed I was struck with the improved
performance of the objective, but referred it to the superior
action of a new microscope which he had made for me, till I
happened to use it for the purpose of shewing the nature of
this defect to a friend. To my surprise it was gone, and the
disc of light was unbroken to the edge, giving 129° instead of
102°, which had been the really effective part of the aperture.
I do not pretend to say that the same occurred in the others
which I examined (in No. 6 the case was certainly different) ;
but it is, at least, desirable that when such a defect is found,
this probability should be kept in mind.* ~ J. R. Rowrinson,
D. D., Armagh.

On an improved Finder for the Wicroscope. —The accompanying
plan for a finder, | have used for some time, and as I have
found it to work very well, and as it has moreover been seen
and approved of by two or three veteran microscopists, I have
ventured to send a description of it to your Journal.

The drawing I send is a view of Ross’s stage to his best
microscope, which is the instrument I use, and to which I
have adapted the finder.

* This microscope deserves to be known: among other valuable im-
provements it has anticipated, and in a better form, one proposed in your
last number, as ‘‘ a new achromatic condenser.” Mr. Grubb’s illuminator
is a prism whose aberrations are corrected for a lamp placed at a given
distance in the plane of the stage. It travels on a graduated are of 120°,
and through this range its focus continues on the object, sufficiently bright
for the highest powers. I have used it at 50° with 3200, and find the
power of examining tissues at various obliquities very useful. If raised
above the stage it gives at once a capital illumination for opaque objects ;
it acts well with Lieberkuhn and Nicol’s prism, and trifling additions
make it equally effective with Mr. Bergin’s parallel illuminator, which
shows some objects with peculiar distinctness.

MEMORANDA. 167

This consists of two scales; one of them, the vertical, A,
is attached to the main bed-plate of the stage; the other,

or horizontal one, B, is attached to the arm carrying the
pinion which works the vertical stage. These scales are
made on thin paper, and on examining a Ross’s microscope,
it will be found that there is ample room for each stage to
work over its respective scale. The horizontal scale B is
carried on a little way, and fixed on the plate of the vertical
stage, as well as to the arm before mentioned.

‘The only thing else required is a small brass stop, fixed on
the sliding plate at G. This is for the slides always to
abut against ; and also two little pegs, or stops, at DD; these
are fixed into the revolving plate, and are for the sliding plate
to abut against. These three stops are removable at pleasure.

The mode of using the finder is obvious :—If, for instance,
I am about to examine a slide of any deposit, for diatomes,
I place it on the stage, close up to the stop G, and bring the
sliding plate down on the stops DD, and set the revolving

168 MEMORANDA.

plate square to the axis of the microscope; on sweeping
through the slide, if any particular form occur worthy of
note, its position is at once read off on the two scales, and
noted thus, “ Triceratium favus 45; the upper numbers
referring always to the horizontal scale, and the lower num-
bers to the vertical.

If I wish at any time to find 7. favus, I have merely to
bring the horizontal stage over 40 on its scale, and the vertical
stage over 20 on its scale, when T. favus must appear. Thus
the whole contents of a slide may be speedily catalogued and
registered, and as speedily found again when required. A
small arrow scratched upon each slide serves to show the
direction in which it is laid, for registry or reference. The
divisions | use are 1-5ths of an inch; each is again divided
into 10 parts: each of these may be divided by the eye into
half, so that when the stages do not come exactly over a divi-
sion, I register them thus: JT. favus 3. It is obvious, that
when working at night these scales will be in the dark; |
then use a small silvered reflector, about two inches square,
which fits into a handle, and throws ample light upon either
of the scales, with a little management.

In the study of diatomaceous deposits this method of
registering is especially serviceable, as the whole contents
of a cabinet may be registered in a book, and any specimen
referred to in a moment, without the least trouble or loss of
time.

I am indebted to my esteemed friend, B. Brodie, Esq., for
the suggestion of the above contrivance.—F. Oxepen, C.E.

@n the presence of Starch in the blood of an Epileptic Patient.—
During the latter part of last year (1853) a gentleman, re-
siding in Toronto, troubled with epilepsy, stated to me that
he was desirous of having his blood examined by means of
the microscope, hoping thereby that something might be dis-
covered in it which might explain the cause of his complaint.
Being fully aware of the great influence which the delayed
excretions of the system exercise when retained in the blood,
I readily acceded to the request, thinking it possible that I
might find some changes in the blood corpuscles, or in the
deportment of the fluids, that might assist in the investigation
or serve to explain the nature of the affection. Having ob-
tained some blood by puncturing the finger with a lancet,
I took a drop and placed it in the field of the microscope
—my microscope is a Nachet’s, magnifying from 450 to 500
diameters. To the drop of bloed I added some pure well-
water, the red corpuscles rapidly absorbed the fluid, and soon

MEMORANDA. 169

broke up; after a short time I found left under the micro-
scope many white corpuscles, and a number of cellaform
bodies which I compared to starch corpuscles ; these bodies
were of irregular size, with a minute nucleus, presented an
apparent lamination, were generally ovate, flattened and some
what irregular in their outline, and bore all the appearance of
these vegetable corpuscles. Fancying that they might be
some foreign matters obtained from the water, which had been
mixed with the blood, I requested a fresh supply of water in
perfectly clean utensils, and used every precaution to obviate
any accidental introduction of starch. Still upon placing
some more blood under the field of the microscope I observed
these bodies. One fact was evident, that if I put some of
the blood under the microscope without the addition of water,
the blood corpuscles ran together and broke up, without
showing any of the bodies I imagined to be starch corpuscles.
When developed to their ordinary size, they were about
1-500th of an inch in diameter, which would make them too
large to pass the generality of capillary vessels; after some
water had been added to the blood these corpuscles, not at
first remarkable, after a time became very conspicuous, and
were evidently fully developed by the water they had absorbed.
The dense medium in which these bodies previously existed
was certainly not favourable to their increase of size, but, as
soon as a finer fluid had been added, they quickly enlarged
and eventually assumed the appearance which attracted my
notice.

Greatly surprised, I mentioned the fact to my patient,
telling him that I must be deceived by some unaccountable
accident, and that the introduction of the starch into the blood
must depend upon some fortuitous circumstances, as I had
never before heard of such a case, and did not believe that a
vegetable product like starch could exist in the blood of man.
So convinced was I that the product observable in the field
of the microscope was starch, that [ obtained some fleur and
placed it under similar circumstances in the field of the
microscope, its apparent identity was sufficiently manifest ;
still fearing that there must be some mistake, I did not ven-
ture to imagine that there could be any reality in my discovery
of starch in the blood of man, and consequently passed the
matter over without further observation. At a subsequent
period I discovered with my friend, Dr. Barrett, similar bodies
during our microscopic observations of the matter contained
in the eye of a boy, which had been removed in consequence
of fungus hematodes, and | have continually observed similar
corpuscles in specimens of urine submitted to the same test.

170 MEMORANDA.

Having lately observed (15th June, 1854) that Rudolph
Virchow had published in Virchow’s Archiv. Bd. VI., H. 1,
page 135 (Sept. 4, 1852), an account of his discovery of a sub-
stance presenting the chemical reaction of cellulose found in
the brain and spinal cord of man, I mentioned the fact to my
patient, told him that it was possible that the discovery which
I had made of starch in his blood might be a reality, and
consequently I thought it would be well to make another ob-
servation of the matters contained in his blood. Upon placing
a drop of the patient’s blood under the microscope it exhibited
the same corpuscles, and I now resolved to test them with
iodine ; accordingly I made a watery solution of iodine, and
applied it to the drop of blood instead of the water previously
employed, and found that every one of the bodies I fancied
to be starch-corpuscles became blue—some were of a light
purplish-blue tint, while others became opaque, and of a per-
fectly blue colour. To satisfy myself as to the precise
character of these bodies, I now took some flour and mixed
it with the weak watery solution of iodine, and precisely
similar results were produced, therefore I consider that I am
warranted in believing that the bodies I observed under the
microscope, in the bloed of the patient afflicted with epilepsy,
were corpuscles of starch ; and that under ordinary circum-
stances, while floating in blood of the usual consistency, these
bodies are scarcely more than granules, and continue as such
so long as they remain in the circulating system ; but when
they have been removed from the blood, or submitted to a less
dense fluid, that they then rapidly take up fluid, and are
readily developed into full-sized starch-corpuscles, and may
be shown as such in the field of the microscope.

While adverting to this singular fact, I will not presume
myself to offer any reasons as to the physiological or patho-
logical value of the conclusions that may be drawn from the
circumstance, save that it seems to confirm the opinion
advanced by Virchow, when he states that ‘ In the brain of
the child I have as yet sought for it (the cellulose) in vain, so
that like the brain-sand it appears to arise in a later stage of
development, and probably may have a certain pathological
import.” Is not this evidenced by the starch-corpuscles
occurring in the blood of a patient subject to epileptic
attacks? It is not impossible that the starch corpuscles
found in the brain, and other abnormal structures of the body,
may have been derived from the blood, and have been depo-
sited in the diseased structures, as one of the products of
inflammatory action ; at that period they were scarcely more
than nuclei, but after they had been removed from the circu-

MEMORANDA. TV

lating system, and obtain a thin serous fluid for their nourish-
ment, they then become so far developed that they may be
readily diagnosed in the animal structures as corpuscles of
starch.—S. J. Srratrorp, M.R.C.S., England ; Editor of the
‘Upper Canada Medical Journal,’ Toronto, Canada West.

Siructure of Closterium.— A paper in the last number of the
* Microscopical Journal,’ by the Hon. and Rev.. G. Osborne,
on the Economy of Clostertum Lunula, induces me to offer a
few remarks on the same topic, as, though my observations
have been trifling compared with the labour which Mr. Osborne
has devoted to those beautifully interesting objects, some draw-
ings and jottings in my note-book entirely coincide with his
illustrations, and afford one or two additional details.

In February 1853, I first noticed around the margin of a
C. Lunula the appearance of a double circulation passing in
opposite directions through canals or vessels, one of which
was, probably from refraction, of a bright pink colour, the
other a pale green. The motion of the currents was nearly
uniform, but occasionally intermittent ; and sometimes for a
few moments the direction of the currents would appear to be
reversed. The circulating liquid carried with it minute
granules by which its course and velocity were apparent ; and
on carefully observing these, it was evident that the marginal
vessels poured their contents into a diffused cavity, free from
endochrome, surrounding the hyaline vesicle with its per-
plexingly active group of moving bodies. These vary in number
from sixteen to twenty or thirty at each extremity of the frond ;
and a supplementary vesicle is sometimes added, containing a
single granule in equally brisk activity. ‘The transparent
membrane of this terminal cavity of the frond appears covered
with cilia, which I have also distinctly seen fringing the inner
margin of the crescent, and less clearly also on its outer edge.

The appearance of a marginal circulation, which passes
uninterruptedly across the central band of the Clostertum; may
or may not be due to ciliary motion, or currents thereby in-
duced. But besides this (apparent) circulation in marginal
vessels, there is a frequent irregular movement of granules of
endochrome more resembling imperfect cyclosis; and a de-
tached granule is occasionally seen to stray into the marginal
current, and to be carried by it to the terminal cavity, where it
appears to have lost its way and to seek in vain for a resting
place.

Another point to which I would ask attention is the occur-
rence of remarkable circular marks or apertures, which are
observed more or less distinctly on many specimens of Clos-

172 MEMORANDA.

tertum. They are alluded to by Mr. Osborne, and are depicted
in several of Ralf’s figures, particularly in C. Ralfsii, and
were even more definitely displayed in several fronds of
C. didymotocum, sent to me among some mud from near Beau-
maris, of one of which I took an outline with the camera in
my note-book, in July 1853, resembling the sketch enclosed.

x 300

This frond seemed nearly, or quite dead ; it was partly trans-
parent, the endochrome contracted, and some portion had
escaped, Several apertures penetrated both layers of the
investing membrane at irregular intervals, the inner circle of
the aperture being the more distant from the eye in all save
one (marked x ), in which the larger orifice seemed in the
opposite direction. All around the apertures and over the
entire space not occupied by endochrome, were crowded
myriads of excessively minute atoms in active motion. Are
these perforations accidental or belonging to the economy of
the Closterium ; and have they any affinity with the mysterious
hyaline globule at its extremity? I have noticed groups of
busy granules in apparently hyaline vesicles on the dark
surface of the frond, though I could not identify them with
the spots here designated as apertures.

The application of iodine was merely a repetition of Mr.
Dalrymple and others’ experiments, and, like his early attempts,
failed to denote the presence of starch in the endochrome.
And yet the Clostertum seemed a fuily mature specimen.

I have not had leisure to watch the process of division
observed by Mr. Osborne, but have noticed the motion of the
Closterium from side to side, recorded by him, a movement
which appeared to me perfectly spontaneous; and, indeed,
without some means of spontaneous motion it is difficult to
conceive how the frond (I had almost said the animalcule)
becomes removed from the bottom to the sides of a glass, a
fact [ have especially noticed in some of the kindred species,
Docidium.

The above observations were made chiefly by the light of a
camphine lamp, or of a sperm candle intensified by a Ross’
condenser, and with one of Ross’ 1-8th of an inch objectives,
of 150° angle of aperture. I have not yet used the direct
sunlight recommended by recent observers, but shall certainly
adopt it when the return of spring gives further opportunities
for the re-investigation of these very beautiful and interesting

objects.—F. G. Wrieut, M. D., Wakefield.

MEMORANDA. 173

Prevention of Glare from Artificial Light—The following very
simple plan for correcting the painful glare of artificial light,
particularly gas light, in microscopical investigations with
low powers may have been adopted by others, but as none of
my microscopical friends are aware of it, and as [ can find no
allusion to it in any works on the microscope with which I
am acquainted, a short note on the subject may not be out of
place amongst your ‘ Memoranda.’ I have had slips of bluish-
grey glass of various shades cut to the size of an ordinary
glass slide three inches by one. One of these blue slips I
place upon the stage under the glass slide bearing the object,
or, if more convenient, place the object to be examined upon
the blue glass itself. This little contrivance renders the
observer quite independent of a blue chimney-glass to his
lamp, and enables him readily to change the tint of the light
and adapt it to the particular object he is examining at the
moment. By this plan the yellow light of common gas is
converted into a pure and white light, approaching very closely
to that of daylight. The blue glass may be obtained from
any working optician, being the glass used in the manufacture
of blue spectacles, and I am confident the observer will derive
real comfort from its use in the manner indicated.—FERGuUSON

Branson, M.D., Sheffield.

Magnetic Stage——I send you a drawing and description of
a magnetic object-holder, not liable to an objection incidental
to the otherwise excellent arrangement described by Mr.

Busk, in the July number of the ‘ Micro-
scopical Journal, inasmuch as it is ap-
plicable to the stage of any microscope,
whether simple or not, and also requires
no new live-boxes or object-holders, being applicable to those

174 MEMORANDA.

already made. The arrangements requires the upper edge of
the aperture in the brass plate of the stage to be turned down
(in a lathe) so as to form a cell 1-8th of an inch or more broad,
and of sufficient depth to allow of a slight shoulder on the
lower edge of the plate. Into the cell thus made a soft iron
ring, cut or turned out of sheet iron, is firmly pressed, being
so made as to fit tightly. If required, small adjusting screws
may be introduced beneath to regulate the requisite projection
of the soft iron ring above the surface of the stage. The
magnets are attached tu the live-box or object-holder, and as the
surfaces of adhesion are by this plan large, they may be much
reduced in weight and more easily made, being punched or
cut out of soft sheet cast steel 1-16th inch thick, and after-
wards hardened in the usual way. The subjoined drawing
shows the mode of attachment to the under surface of the
brass live-box or object-holder, and which may be effected either
by screws or solder, taking care that the opposing and dissi-
milar poles of the magnets are brought as near as possible
without contact. As magnets always lose power by frequent
breaking contact, this arrangement allows them to be remag-
netized without any disturbance of the stage of the microscope.
Both magnets and soft iron ring require to be ground flat.—

J. B. Spencer, 9, Kidbrooke Terrace, Blackheath.

Curious effect of moisture on the markings of the Pleurosigma.—
In the Introduction to the ‘Micrographic Dictionary,’ now
publishing by Van Voorst, and of which Dr. Griffith and
Mr. Henfrey are the authors, it is stated, page xxxiii, ‘ In the
valves of the more delicate Diatomacee (Gyrosigma, &c.),
the point is important that the line of fracture of the broken
valves passes through the rows of dots on the dark lines cor-
responding to them, showing that they are thinner and weaker
than the rest of the substance; had these dots represented
elevations, the valves would have been stronger at these parts.”
This appears very conclusive, but a phenomenon has recently
come under my notice which, to my mind, is easily explicable
on the supposition that the dots are elevations ; not so, how-
ever, on the hypothesis that they are depressions. On a slide
containing the Pleurosigma hippocampus, mounted dry by the
late Poulton (whose recent loss many microscopists will I am
sure deplore), there is one specimen of a Pleurostgma which I
am unable to identify with any in the Rev. W. Smith’s
Synopsis. Some moisture has gradually insinuated itself
between the thin glasses of the slide, and has almost entirely
obscured the markings which I used formerly to see most
beautifully as dots all over the surface of the shell. However,

MEMORANDA, P75

on submitting the slide to a gentle heat, I found that the
moisture slowly retreated, leaving patches of the shell dry,
and with the markings as distinct as before. But what I
particularly desire to draw attention to is, that ] have observed
the dry part of the shell is uniformly bounded by straight
lines, which are parallel to the two directions of least dis-
tance of the dots. This will, perhaps, be better understood
on referring to the figure, which is an enlarged diagram of a
portion of half the shell, and in which the portion in dots is a
careful copy of a dry part of the
shell, where the markings are
clearly seen; whilst the shaded
remainder of the figure is intended
to represent the parts obscured
by the damp, in which only a
very slight trace of the markings
is visible. In the figure it is
evident that there are two lines,
AB and AC, in the directions of
which the dots are at a minimum
distance, and I find that the
straight lines of demarcation be
tween the moist and the dry portions are almost universally
parallel to these two directions.*

Now upon the supposition of these little dots being eleva-
tions, the phenomenon appears to me easily explicable, on the
principles of capillary attraction. We can readily conceive
the moisture clinging from one dot to another, and it would
always have a tendency to arrange itself in lines parallel to
the directions of least distance. I am, however, quite at a
loss to imagine how the same principle would apply on the
hypothesis that the dots are depressions; nor, on that hypo-
thesis, do [see upon what principle the phenomenon is expli-
cable. The examination has been made throughout with one
of Ross’s recent 1-8ths (1854), and a carefully centered achro-
matic condenser, with stop to cut off the central rays. Ll always
observe that when I have the most distinct vision of the dots,
if I very slowly turn the fine adjustment so as to depress the
object-glass, the dots suddenly become white on a black
ground, and under these circumstances I have sometimes
thought I could see the white dots having an hexagonal form ;
but even with the third eye-piece, I have not command of

* From geometrical considerations it is evident, that if the angle BAC
be greater than 120°, the straight lines parallel to the straight line AD are
in the directions of the minimum distance of the dots, but by a careful
drawing with the camera lucida. I have found that the angle BAC is less

than 120°.

176 PROCEEDINGS OF SOCIETIES.

sufficient power to be assured on this point. The fact of these
delicate markings being almost entirely obscured by moisture
appears to me remarkable, and calculated, if investigated by
experienced microscopists, to throw much light on a subject
still I presume involved in obscurity, namely, the precise
nature of these markings. I may observe that I have
another slide of the Pleurosigma angulatum, in which, from
the same cause, the phenomenon is very visible.—G. Hunr,
Birmingham.

Notes to Wir. Currey’s Paper on the Threads of Trichia.— The
following misprints occur in this paper. At p. 20, the word
“accurate” is printed instead of ‘ arcuate,” which renders
the sentence unintelligible. In two places Trichia is printed,
where the word should be Trichie, and in one place Arcyria
is printed instead of Arcyrie¢.—FrEpERICK CurREY.

PROCEEDINGS OF SOCIETIES.

Microscorican Society. June 28th, 1854.
Dr. Carpenter, President, in the Chair.

T. H. Huxley, Esq., Joseph Payne, Esq., E. B. Pitchford, Esq.,
and F. Spurrell, Esq., were elected Members.

Dr. Lankester made some remarks on the circulation in Closterium
Lunula, and read portions of a communication to the Microscopical
Journal, from the Rev. S. G. Osborne, on the subject.

A paper on the Parasitic Borings in Fossil [ish-scales, from
C. B. Rose, Esq., was read (Transactions, vol. iii., p. 7).

Mr. Quarles Harris made a communication on the disease affect-
ing the Vine.

October 28th, 1854.
The President in the Chair.

Three separate papers from Professor Gregory, of Edinburgh,

on Diatomacez, were read (Transactions, vol. lii., p. 10).

November 22nd, 1854.
The President in the Chair.
H. Rutt, Esq., and Fitzmaurice Okeden, Esq., were elected
Members.
A paper was read from Mr. Wenham, entitled, “‘ Some Remarks
on obtaining Photographs of Microscopic Objects,” &e. (Transac-
tions, vol. iii., p. 1).

GILT),

ORIGINAL COMMUNICATIONS.

On the OccURRENCE among the Inrusorta of peculiar ORGANS
resembling THREAD-CELLS. By GrorceE J. ALLMAN, M.D.,
F.R.S. (With a Plate.)

(Read at the Meeting of the British Association at Liverpool, Sept. 1854.)

In an important monograph by Cohn on the Paramecium
Bursaria,* this author maintains that the cilia with which the
whole surface of the animalcule is covered are in reality much
longer than their appearance in the living animal would lead
one to believe. He founds this opinion on the fact, that
when the animal is allowed to dry on the glass object-holder
it is seen to bristle with long rigid filaments, which he be-
lieves to be the cilia, really unaltered in length, though then
for the first time become visible in their entire course; and,
in accordance with this view, he figures the Paramecium
covered with cilia very much longer than the inspection of
the living animal alone would justify.

Stein, in his remarkable work on the development of the
Infusoria,t refers to this opinion of Cohn, whom, however, he
considers in error, in supposing the long bristle-like pro-
cesses of the dead animalcule to represent the natural length
of the cilia in the living. He maintains on the contrary that
these processes are the cilia abnormally lengthened under ex-
ternal influences; and he states that he has witnessed the
same phenomenon in many other Infusorta in which he has
always been able to induce it by the application of strong
acetic acid, when the cilia suddenly extend themselves to
three or four times their original length.

While recently engaged in examining the structure of a
nearly allied animalcule, the Bursaria leucas, Ehr.—a green
variety of which was developed during the present autumn in
great profusion in a small pond in the county of Essex—I
witnessed an appearance exactly similar to that described by
Cohn and Stein; but it soon became clear to me that the
German naturalists had erred in their explanations of it; and
I am now satisfied that the filaments in question have nothing
whatever to do with the cilia, but are peculiar and very re-
markable organs, hitherto undescribed in the Infusoria.

When this animalcule is examined under a sufliciently

* Siebold u. Kolliker Zeitschrift. Bund III. 260.

+ Die Infusionsthiere auf ihre Entwickelungs geschichte. (‘ Quarterly
Journal of Microscopical Science,’ Vol. ii., p. 272.

VOL. IIT. N

178 ON SOME PECULIAR ORGANS OF THE INFUSORIA.

high power, minute fusiform bodies may be detected thickly
imbedded in its walls. (Figs. 11 and 12 and 14h, Plate X.)
These bodies are perfectly colourless and transparent; they
are about the 1-2500th of an inch long, and may easily, even
without any manipulation, be witnessed at the margin, where
they are seen to be arranged perpendicularly to the outline
of the animalcule, while on the surface turned towards the
observer their extreme transparency and want of colour render
them invisible against the opaque back-ground, and it becomes
necessary to crush the animalcule beneath the covering-glass
so as to press out the green globules which it contains, in
order to bring the fusiform bodies into view. ‘To these bodies
I propose to give the name of trichocysts.

As long as the animalcule continues free from annoyance,
the trichocysts undergo no change, but when subjected to ex-
ternal irritation, as occurs during the drying away of the sur-
rounding water, or the application of acetic acid or other
chemical irritant, or the too forcible action of the compressor,
they become suddenly transformed into long filaments, which
are projected from all parts of the surface of the animalcule
(fig. 13); and it is these filaments which, being mistaken for
cilia by Cohn and Stein, gave rise to the erroneous views just
mentioned,

The rapidity with which this remarkable change is effected,
joined with the great minuteness and transparency of the ob-
ject, renders it extremely difficult to follow it, and for a long
time I could only satisfy myself of the fact that the fusiform
bodies were suddenly replaced by the projected filaments.
After continued observation, however, I at last succeeded in
witnessing the principal steps in the evolution of the fila-
ment.

It is not difficult, by rapidly crushing the animalcule, to
force out some of the trichocysts im an unchanged state.
(Fig. 15.) If the eye be now fixed on one of the isolated tri-
chocysts, it will most probably be seen after the lapse of a
few seconds to become all at once changed with a peculiar
jerk, as if by the sudden release of some previous state of
tension, into a little spherical body. (Fig. 16.) In this con-
dition it will probably remain for two or three seconds longer,
and then a spiral filament will become rapidly evolved from
the sphere, apparently by the rupture of a membrane which
had previously confined it, the filament unrolling itself so
quickly that the eye can scarcely follow it (fig. 17), until it
ultimately lies straight and rigid on the field of the micro-
scope, looking like a very fine and long acicular crystal.

(Fig. 18.)

GLAISHER, ON SNOW CRYSTALS. 179

This remarkable body when completely evolved (fig. 18 /.)
consists of two portions—a rigid spiculum-like portion acutely
pointed at one end, and continuous at the opposite end with
the second portion, which is in the form of an excessively fine
filiform appendage less than half the length of the spiculum :
this second portion is generally seen to be bent at an angle on
the first, and is frequently more or less curved at the free end.
The form of the evolved trichocysts is best observed in such
as have floated away towards the margin of the drop of water,
and are there left dry by the evaporated fluid. In many of
them the filiform appendage was not visible, and they then
merely presented the appearance of a simple, long fusiform
spiculum. (Fig. 18k.)

The resemblance of the organs now described to the well-
known thread-cells of the Polypes, and of certain other lower
members of the animal kingdom, is obvious. That they are
entirely homologous, however, with these bodies we can
scarcely yet assert. Their origin, at least, appears to be
different; for if we admit the unicellular structure of the
Infusoria, we have the trichocysts apparently developed in the
substance of the cell-wall, instead of being produced in
special cells, as we know to be the case with the thread-cells

of the Polypes.

Snow Crysrats in 1855. By J. Guatsuer, Esq., F.RS.
(Read before the Greenwich Natural History Society.)

THE many snow crystals which fell during the late severe
weather, attracted such general attention, that I ventured to
announce a paper on the subject for the present evening.
Never do I recollect such an infinity of crystals as have lately
fallen beneath my observation. Generally speaking, they fall
at rare intervals and very sparingly, in cold and calm weather,
and frequently at the commencement of a thaw. In the
present year they have fallen under all circumstances of wind
or calm, with snow, and alone, during the continuance of the
late severe weather when the temperature varied from a few
degrees above zero to the freezing point, and up to the precise
moment of the thaw, with a temperature of from 34° to 37°. The
size of these beautiful objects was by no means unappreciable,
and might be said to vary from 0:05-inch to 4-10ths of an
inch in diameter. Their forms were so varied, that it seemed
scarcely possible for continuous observations to exhaust them
all. I therefore endeavoured to secure observations of those
which might be considered types of their class, trusting to a

n 2

180 GLAISHER, ON SNOW CRYSTALS.

future opportunity to extend my acquaintance with the
separate varieties which each class included. In accordance
with the law that water crystallizes at an angle of 60’, the
base of every figure was a hexagon of six rays. ‘These rays, in
passing through successive stages of crystallization, become
encrusted with an endless variety of crystalline formations,
some consisting of thin laminz alone, others of solid but trans-
lucent prisms, heaped one upon another, and others gorgeously
combining laminze and prisms in the richest profusion.

At the beginning of the frost, the kind which was most
common, and attracted universal attention, was of simple six-
rayed stars, with a central molecule of snow. These fell in
clusters of several in a group, and in their descent had the
appearance of tolerably large and fleecy snow-flakes. The
ground had for some days been covered with snow ; but where
the soil was visible, they lay like ravellings of fine white
cotton, knotted here and there, an effect produced by the
large white molecule, the centre of each star. I chanced
to be in the neighbourhood of Abbey Wood, when a shower
of these fleecy-looking groups began to fall. The air was
calm, the snow lay upon the ground, and the sky was over-
cast. ‘The surface of the snow was soon covered with clusters
of these figures, beautiful in their simplicity. They were
certainly 4-10ths of an inch in diameter, and could be readily
distinguished. The temperature at this time was at or near
32°. After falling about a quarter of an hour, they became
intermingled with a variety of very complex crystals. Some
of these last exhibited all the rigidity but harmonious pro-
portions of geometric figures; others the fanciful luxuriance
of the fronds of the Lady fern; others, again, exhibited an
arrangement of trefoils, and some there were, with pinne of
unequal size, three being large and fully-developed, of fern-
like character, and three being little more than spicule. The
air, during the continuance of the shower, was considerably
cooled, and was at its coldest when these beautifully-varied
figures were falling. Towards the close of the shower, fleecy
groups of stars were again prevalent, the air was less cold,
and half an hour after, when the shower ceased, the sun was
endeavouring to penetrate the gloom which before prevailed.

I will endeavour briefly to describe the departures from
the ordinary or primitive form.

On February 8, the day of the first heavy and continued
snow, | secured drawings of some of the most remarkable
figures which fell in numbers throughout the day, and accom-
panied the snow. ‘The minimum temperature of the preceding
night had been 29°; at 9 o’clock the thermometer in air was

GLAISHER, ON SNOW CRYSTALS. 181

32°, and the maximum during the day was only 82°. During
the early part of the morning there fell an immense number
of hexagonal plates of ice; some of these were of simple
lamin, but others were marked very beautifully with inner
lines, and resembled in form and character many of those seen
by Scoresby in the Arctic seas. ‘Towards noon, I perceived
several of more complicated figure, of which the hexagon of
the morning formed the nucleus. Figs. 1, 2, 3 (PI. XIII.)
are a few of several that I sketched at tiie ome and were
viewed through a lens of somewhat less power than a Cod-
dington. Fig. 1 exhibits an arrangement of prisms, set upon
rays of which two were longer than the remaining four. I
have only once since met with this arrangement.

Fig. 8 was small and intensely glistening, Fig. 2 is com-
posed of two distinct figures, of which the second or inter-
mediate is the more simple; I met with each singly more than
once during the morning.

Towards the afternoon, this class of figures was exchanged
for others of an arborescent character, the six-sided laminae,
however, still continuing to fall, but more sparingly. At long
past midnight when I went out of doors, the crystals sparkled
in the snow, like mica in a piece of granite, and every cobweb,
every leaf, and knotty projection was laden with countless
myriads of crystals, which seemed to defy every effort to
individualize their character, or group them into classes.

On February 13, | made further observations. Fig. 4 is
the only drawing I have yet completed of the several which
fell on this day. Its diameter was about 0-05-inch. It
glistened brightly, and was highly crystalline. Its general
effect was similar to the drawing, and the clusters of prisms
round the outer boundary of the figure chiefly arrested the
attention ; the nucleus appeared a glistening speck.

February 16 afforded me another opportunity of continuing
my observations. The minimum of the preceding night had
been 23°, at 9 o’clock the temperature in air was 25°, ‘and the
maximum for the day was 33°8°. The arborescent form
chiefly prevailed.

Figs. 5, 6, 7, are well illustrative of their class, of which
they are among the most simple types that could be selected.
In figs. 5 and 7, the nucleii, it will be perceived, are prisms
set around the centre, with great formality of arrangement ;
the spicule are surmounted with leaves; these, for the most
part, are serrated and slightly curved, and are set upon the
main radii, at the same Sele (that is 60°) with that of the
prisms, with which, in figs. @ 7 they are intermingled.

Fig. 6 is well Alineuatine of an intermediate stage of

182 GLAISHER, ON SNOW CRYSTALS.

crystallization ; three of its prisms, it will be perceived, are
in a more advanced stage of formation than the other three.
Sir Edward Belcher informs me that he intends to adopt this
as an example of intermediate crystalline formation in his
appendix to the work he is now preparing on the meteorology
of the Arctic seas.

On February 17, there fell an inconceivable variety of
crystals, at times accompanied with light snow, but, for the
most part, alone. The minimum of the preceding night was
18°, the temperature at 9h. was 22°, and the maximum of the
day was 33°. Figs. 8 to 15 are some among the large
number that I was able to sketch at intervals throughout the
whole of the day. Figs. 8 and 9 were very minute, but
exhibited, as seen through a Coddington, a considerable degree
of solidity, the prisms being either cubes, hexagonal, or cut
with many facets. I sketched nearly twenty varieties on this
day, and was surprised at their similarity ; they were evidently
formations under nearly identical conditions.

On February 21, I was fortunate enough to secure some
good observations of double crystals. I had observed many
previously, but had not before been in a condition to record
them with success. The minimum of the preceding night
was 2() 9°, the temperature at 9h. was 21°, and the maximum
for the day was 30 2°.

I particularly noticed the two specimens, figs. 16 and 17,
which were at least 0:4-inch in diameter, and were composed
of solid prisms grouped around the radii of the crystal. I have
endeavoured to communicate solidity to these figures, which
struck me as being intensely beautiful and rich in point of
effect. I should, perhaps, mention, in the event of the
drawings not sufficiently explaining themselves, that a double
crystal is that in which two crystals are united by an axis
at right angles to the plane of each. The rays of the under
crystal most frequently fell intermediate between, and a little
projected beyond those of the upper.

I have yet to speak of an order of crystals, more complex
and exhibiting a more graceful arrangement than any I have
yet shown to you. I refer to those which combine lamin
and prisms with the leafy or arborescent formation. 1 am
indebted for drawings of two specimens of this class to a lady
of my acquaintance, Mrs. King, who, it will be remembered
by the readers of the ‘ Illustrated London News,’ on a former
occasion, kindly supplied to me the fruit of her observation.
(See fig. 8.)

The first to which I shall refer is as graceful a combination
as can possibly be imagined, and exhibits a nucleus com-

GLAISHER, ON SNOW CRYSTALS. 183

posed of two hexagons, so centred as to present a double
set of angles; from six of these spring the main radii of
the figure, surmounted by crystalline plates or lamine of
(Mrs. King informs me) the greatest transparency. From
these lamine spring leafy tufts, which as it were, crown the
structure. The lower part of the ray, near the nucleus, serves
as an axis for an elongated prism, near the apex of which
spring on either side, leaflets of graceful form. intermediate,
and springing from the angles of the under hexagon, are a
set of shorter rays, the axes of similarly elongated prisms,
surmounted on the top by three others, the one of similar, the
other two of dissimilar figures. It is hardly possible to imagine
a more graceful composition, which is greatly enhanced by
the delicacy and admirable execution of the drawing.

The one to which I now refer, is also drawn by Mrs. King,
and, like the other, was observed under a microscope. It
is composed of leaflets and laminew, and its nucleus is a
single hexagonal star. It is less elaborate, but scarcely less
graceful than the former. The drawing of the figure claims
equal merit with the preceding. I am greatly indebted to
Mrs. King for having two such graceful and elaborate
specimens to add to the several which I have received
from various sources, and which claim no competition with
them, in regard to the grace and intricacy of their structural
details.

The last morning of the frost presented me with the means
of accurately observing a few more facts in connexion with
this most interesting subject. When I commenced observing
at 9h., the temperature was a little above 32°. A fine snow
was then falling, accompanied with thick snowy, ill-defined
figures, such as are frequently to be met with at the com-
mencement of a thaw. | examined several of these with my
Coddington, and found them to consist of an assemblage of
short, half-formed prisms, set on and around a nucleus, at
various angles. The prisms themselves were hardly angular,
were of irregular length, and notched here and there. With
these figures fell innumerable spicule, which, under the glass,
resolved themselves into prisms, with blunted angles, which
had much the character of the icicle, and terminated in a
spike. They fell singly, and were of variable length. To
the naked eye they appeared of snowy consistency, but unde1
the glass of crystalline transparency. The temperature was
rapidly ascending.

After a while, these figures almost entirely disappeared,
but a leaf-like pinna was here and there to be detected: a
remarkable calm and silence pervaded the air. At 11 o’clock,

184 GLAISHER, ON SNOW CRYSTALS.

with a still ascending temperature, the snow was-replete with
simple, stellated forms, chiefly of laminz. Double crystals
were very numerous, and I secured sketches of several which
I have not yet had time to complete. Fig. 18 represents a
double crystal of the prevailing character. | am also again
indebted to Mrs. King for another very beautiful and charac-
teristic figure, which she observed on this morning; the
minute sets of markings around the edge, have reference to a
frosted effect, which communicated additional beauty to the
original, .

Owing to the high temperature, the figure of the crystals
continued rapidly to change; collapsing in the most curious
and kaleidoscope manner possible, the upper groups of prisms
collapsing first, the next in order next, and so on. When I
say collapsing, I mean the sudden dissolving of three or more
prisms into one, a change effected with instantaneous rapidity.
The next stage of dissolution was the rounding of every angle
that remained, and the next stage to that, the thickening and
elongation of spicula, which had served as axes to the prisms,
and which derived accession from the dissolving and half-fluid
matter of the prisms.

In this manner they continued to exchange one simple form
for another still more simple, until the pristine drop of water
occupied the site of the former crystal.

Whilst sketching fig. 18, I saw it undergo a variety of
changes, until the several groups of prisms, of which it was
composed, collapsed into the figure before you, when every
trace of inner markings had disappeared, and the crystal re-
mained of a watery transparency, until it finally dissolved.
Figs. 19 and 20 are specimens in a partially dissolving state.
From fig. 20, the upper prisms have all but disappeared ; and
in fig. 19 midway up the pinnz it will be perceived that some
of the prisms have already dissolved, and given place to an
irregular and serrated spike, which somewhat impairs the
original harmony of the figure.

At noon the snow had all but ceased. The temperature
attained to 37°. Cocks crew as anticipating a change; the
birds, which for six weeks previously had been silent,
answered each other from the trees; icicles two feet in length,
which I had noted for sixteen days previously, were fast
melting away: all nature but the birds seemed motionless,
as waiting the advent of a change; and, what is rarely seen,
the trees were dripping moisture while the snow lay like a
rime upon their branches and bended stems. Half an hour
after, the thermometer rose to 388°, and a complete thaw set in.

At 2 o'clock, the thermometer was 35:°5°, small and fine

ON THE TORBANEHILL MINERAL, ETC. 185

snow was falling, water was dripping everywhere, the birds
were singing joyously, and a dead calm prevailed.

I am not prepared at the present time to enter into any
discussion respecting the circumstances of these formations.
They involve, I have reason to believe, very compound con-
ditions. As anything that I could say at the present time
would require the confirmation of repeated observations and
experiment, I am prepared to follow out the iavestigation as
far as possible, and to defer all conclusions for the present.

An INVESTIGATION into the STRUCTURE of the TORBANEHILL
Mineral, and of various kinds of Coat. By Joun HuGuHes
Bennett, M.D., F.R.S.E., Professor of the Institutes of
Medicine in the University of Edinburgh. (From the
Transactions of the Royal Society at Edinburgh.)

THE investigation, of which I am now about to give an ac-
count, was undertaken with the view of determining whether
the structure of the Torbanehill mineral was similar to or
unlike that of coal. I was aware that the subject would
be brought before a court of law, and that many scientific
persons of great eminence had already spent much time in the
inquiry. With the understanding, therefore, that my evidence,
should it be required, was to be limited to the structure of
coal and of the mineral in question, | gave directions to Mr.
Bryson, the optician, of this city, to make thin sections of
attested specimens of various coals and of the mineral, con-
ceiving that a careful examination of them would easily deter-
mine the point. It was soon apparent, however, that a far
more extended series of researches was necessary than I at first
anticipated ; but as it was also evident, from the marked
structural differences which were observed in the sections, that
the investigation would not be destitute of positive results, I
determined on pursuing it to a conclusion.

The plan adopted was, in the first instance, to make myself
familiar with the structure of the ordinary household coals
used in this city, of which those called the Zetland and the
Dalkeith or Buccleuch coals may be considered as the types.
I then examined the structure of the Wallsend, Newcastle,
and various other kinds of household coal, in every case ob-
serving, with magnifying powers of various diameters, thin
sections made horizontally and longitudinally with the line of
stratification. I next examined similarly-made thin sections
of the Torbanehill mineral, and was struck with the remark-
able dissimilarity which existed between them. I now had

186 DR. BENNETT, ON THE STRUCTURE OF

numerous sections prepared of various cannel coals, and having
previously determined the appearances presented by true coal
and by the mineral, I was readily enabled to distinguish the
various shades of differences between them. I saw _ that
although the cannel coals, and especially one of them, the
Brown Methil, approached in structural character to that of
the Torbanehill mineral, it could still be distinguished from
it by a practised eye; and that although gradations existed
between these different substances, there was at least one
element which served readily to characterize all the different
kinds of coal I had hitherto examined, and which was not
present in the mineral. I now went over the sections of coal
in the rich collection of Mr. Alexander Bryson of this city,
and subsequently carefully examined the numerous sections
made by Dr. Adams of Glasgow. Before the trial of Gillespie
versus Russel came on, Dr Adams, Mr, Quekett, and myself,
spent nearly an entire day together, examining each other’s
specimens, and carefully reinvestigating the whole subject.
It was then that the character of the ashes in the various sub-
stances we had examined was pointed out tome by Dr. Adams,
who, in my opinion, is entitled to the greatest credit for the
laborious, skilful, and successful efforts he has made in deter-
mining the structure of numerous coals, and pointing out the
differences they exhibited, when compared with the Torbane-
hill mineral. At this meeting, also, we compared the structure
of coal with various kinds of recent woods ; we incinerated the
mineral and certain coals, and carefully examined the ashes ;
and there was established, as the result of this conjoined in-
vestigation, as well as from the independent researches made
by Dr. Adams in Glasgow, by Mr. Quekett in London, and
by myself in Edinburgh, the most perfect accord with regard
to all the facts which had been elicited during the inquiry.
At the commencement of the present session, I brought the
subject under the notice of the Physiological Society of this
city, who appointed a committee, composed of four gentlemen
in addition to myself, all of ae had long been nebustieee
to the use of the microscope, and were Gatilacee with vegetable
and animal structures. Three of these gentlemen, viz., Dr.
Cobbold, and Messrs. Barlow and Kirk, made farther inquiries
and researches, which served to elicit additional facts, and to
demonstrate, in the language of their report, that “the Tor-
banehill paateall is widely different from every kind of coal.”
Lastly, with a view of meeting certain theoretical objections
which have been advanced, I have carefully examined the
structure of various kinds of peat, as well as the stems of recent
ferns and several fossil plants, which have only served to

THE TORBANEHILL MINERAL, ETC. 187

establish the entire absence of connexion between these sub-
stances and the Torbanehill mineral.

In now endeavouring to place in a condensed form the
results of this extended investigation before the Society, I
propose, in the first place, to describe the facts, as they may
be easily demonstrated in the field of the microscope.
Secondly, to deduce from these facts the structural element
which distinguishes every kind of coal from the Torbanehill
mineral, and explain the cause of the differences which are
recorded in the proceedings of the recent trial. Lastly, to
offer a few speculations as to the nature of this mineral, as dis-
tinguished from various kinds of household and cannel coals.

I. When we examine a piece of undoubted coal, such as of
the Zetland or Buccleuch coals, it presents to the naked eye a
fibrous structure, and has a black shining streak. It has been
found difficult to make thin sections of it, as in the grinding
process it readily crumbles down. But when a tolerably thin
slice, made in the direction of the fibres, is with great pains
obtained, and examined with a magnifying power of 200
diameters linear, it is then also seen to possess a fibrous struc-
ture. These fibres may be observed to be composed of a
reddish-brown coloured substance, in the centre of which is
sometimes a dark streak. Oval and elongated transparent
masses of a light yellow or reddish-brown colour may also be
seen running parallel with the fibres, and here and there are
colourless spaces, which strongly reflect light, and which are
evidently filled with a crystalline mineral substance.

On examining a section horizontal to the former one,
parallel with the plane of stratification, a bistre-brown or
blackish opaque mass is seen, containing a number of rings of
a transparent yellowish or reddish colour, with an opaque
centre. ‘These rings are from the 1000th to the 1500th of an
inch in diameter, and resemble the transverse sections of tubes
running at right angles to the fibres of the coal. ‘Phere may
also be observed larger masses of a reddish-brown transparent
material, varying in size from the {th to the ,},th of an inch
in diameter. There are also visible, circles or rings of a rich
golden yellow matter, much larger, and varying in size from
the 50th to the 6th of an inch, which have been described by
some as seeds or spore cases.

Similar appearances may be observed in the Wallsend,
Newcastle, and all the other household coals I have examined,
although in some of them, especially Newcastle coal, this
structure is more obscured, than in the Scotch coal, by dense
black opaque matter. Here and there, however, in the New-
castle as well as in the Hamilton and some other coals, it may

188 DR. BENNETT, ON THE STRUCTURE OF

be found to present a highly fibrous fracture, minute chips of
which exhibit at their edges distinctly dotted or porous ducts.

On examining the Torbanehill mineral with the naked eye,
it is destitute of a fibrous structure, and presents a homoge-
neous appearance in whatever way it is fractured or cut. It
is tough and hard to break, when compared with coal, has a
dull brown streak, and is readily ground down into thin slices
of any degree of tenuity. Some specimens are of a dark, and
others of a light brown colour. The section of a dark speci-
men seen under a magnifying power of 200 diameters, presents,
first, a number of yellowish and reddish-brown transparent
masses, of a rounded form with an irregular outline, varying
in size from the ;,5;th to the ;},th of an inch in diameter.
These are surrounded by a dark opaque substance, in whick
they appear to be imbedded, and in which no trace of struc-
ture can be detected. These light and dark substances vary
in relative amount in different specimens of the mineral, and
according to the thickness of the section. In some specimens,
the rounded transparent masses are more widely separated by
the opaque substance, but in others, they are often so close,
that a very thin section presents a homogeneous appearance of
yellowish or reddish-yellow matter, resembling bees-wax, with
only a few irregular spots of the black matter. In some sec-
tions, especially of the light-brown specimens, the rounded
masses, as they are ground thinner, may be seen, as it were, to
melt into one another. In such sections, no difference what-
ever can be made out, whether they be made in a longitudinal
or in a horizontal direction.

In some thin sections, these rounded transparent bodies can
be separated from one another, and be distinctly seen to
possess a radiated crystalline appearance, strongly reminding
one of the crystals of carbonate of lime which occur in urine.
At certain angles, also, a few of them refract light, and become
strongly tinted with the orange ray when polarized,—a cir-
cumstance perhaps dependent on the admixture of mineral
matter. When a section of the mineral, presenting both the
substances described, is held over the flame of a lamp, the
yellow matter evaporates in the form of thick smoke, leaving
the black matter unaffected, with large holes or loculi in it. It
must be clear from this experiment that the yellow matter is
some bituminous or resinous substance, easily decomposed by
the heat of a lamp, and that the black matter is an earthy
material, which resists the same amount of heat. We can
have no doubt, therefore, that an easily volatilized and highly
inflammable matter has concreted in the form of rounded
masses, and constitutes the light-coloured portion of the mi-

THE TORBANEHILL MINERAL, ETC. 189

neral formerly described. Whether this be chemically the
same as, or only allied to bitumen, resin, or amber, I leave to
be determined by chemists. But we may at least correctly
denominate it a Bituminoid substance, that is, one which
closely resembles, even should it turn out not to be identical
with bitumen. The matter in which this is imbedded seems
for the most part to be composed of clay, or earthy matter
which leaves a white ash, altogether destitute of structural
traces, and is equally amorphous in whatever direction the
section of the mineral is examined.

Some portion of the Torbanehill mineral, however, has a
tendency to split up into thin lamin, and presents smooth or
irregular depressions, dependent on the presence of Stigmaria
or other fossil plants, which, in these places, come in contact
with, or are imbedded in, the substance of the mineral. Thin
sections of such portions exhibit masses of a rich-brown colour,
composed of scalariform ducts in great numbers, and occasion-
ally the woody fibres and rings of coal. These latter are
most common where the mineral forms a junction with coal,
and where the one is more or less mingled, or alternates with
the other. In these places the great difference in structure
between them is easily recognised both by the naked eye, and
by microscopic demonstration. By the naked eye, the black
shining layers of coal are easily distinguished from the brown
dull appearance of the mineral, and wherever such coal exists,
the streak is dark and lustrous; wherever the Torbanelill mi-
neral is pure, and unmixed with vegetable matter, it exhibits the
dull-brown streak. In such places, the mineral is characte-
rized, under the microscope, by its yellow masses and black
basis ; the coal, by its rich-brown fibrous structure. Occa-
sionally sections at the point of junction, prove that the scala-
riform tissue, like the substance of coal, is very friable and
easily broken down. ‘This fact, which was pointed out to me
by Mr. Kirk, induced him to think that the amorphous basis
might be composed of such tissue disintegrated, a supposition
negatived by the absence of all trace of structure through
the mineral generally.

From what has been said it must be evident, that there is a
wide distinction between all kinds of household coal and the
Torbanehill mineral ; and the correct discrimination between
the fibrous, woody texture of the one, and the granular bitu-
minoid, and earthy substance of the latter, will enable us to
understand the more confused texture presented in certain
cannel coals, which it has been contended are identical in
structure with the mineral.

I have examined a large number of cannel coals, and in

190 DR. BENNETT, ON THE STRUCTURE OF

every case have been enabled to recognise the fibrous structure
of the longitudinal section, and the appearance of rings in the
transverse sections, as they are seen in household coal, They
contain, however, a greater or less number of the bituminoid
masses, identical with those which constitute the principal
substance of the Torbanehill mineral.

The Capeldrae and brown Methil coals are especially rich
in these bituminoid bodies, and in consequence have been
regarded as identical in structure with the mineral. In some
sections of the latter coal, they are almost as numerous as those
in the dark specimens of the Torbanehill mineral; but a
careful examination will show that it also possesses the same
organic structure as coal, and may be at once distinguished by
its reddish fibres, when cut in one direction, and by the distinct
rings, though few in number, observed on a transverse section.

I consider that this proof of structure in the brown Methil
coal, is decisive of the question as to the distinction between
coal and the Torbanehill mineral. Every one allows, that of
all the cannel coals, the brown Methil is the one which most
closely resembles it. It has also been reported that no differ-
ence can be detected between them by the aid of magnifymg
glasses. To this I may reply, that I have always been able
to distinguish them at once; that I have never been deceived
in doing so, although the attempt has often been made; nor
do I believe that any histologist who has made himself ac-
quainted with the structure of coal on the one hand, and of
the Torbanehill mineral on the other, could easily confound
the two together.

There are two other modes of examination which also indi-
cate the broad distinction in structure between coal and the
mineral, These are by reducing them to powder and to an ash.

The powder of household coal contains numerous short
black fibres, separated or aggregated together, mingled with
mineral particles and fragments of cells. That of the Tor-
banehill mineral is composed of transparent yellowish masses,
evidently the same as those seen in section, but more broken
up, and without any trace of an envelope, mingled with frag-
ments and the debris of the dark amorphous mineral matter.
This mode of examination, though distinctive between the
household coals and the mineral, is not so much so, when the
brown Methil coal is chosen as the subject of comparison.

An examination of the ash, however, is still more character-
istic. In the brown or blackish ashes of coals will be found,
Ist, A greater or less number of mineral spicula, evidently
the skeletons of the woody fibre; 2nd, Siliceous masses of
various irregular forms, obtained from the interstices of the

THE TORBANEHILL MINERAL, ETC. 191

organic substance ; 3rd, Black fibres, separated or in masses,
evidently the woody fibre carbonized ; 4th, Flat carbonaceous
plates, presenting round apertures cortespanding im size to
the woody cells which passed through them, and exhibiting at
their margins sections of larger joneles which tloagelec:
bounded ile large resin cells = the recent wood. None of
these appearances are visible in the ash of the Torbanehill
mineral, when care is taken to exclude such portions of it as are
free from the stigmaria or other plants imbedded in it. Indeed
I myself have never seen such appearances in the ash, even
when no such precaution has been taken. Dr. George Wilson
gave me a considerable quantity of it, which everywhere ex-
hibited nothing but an amorphous material, such as might
result from the incineration of clay or other earthy non-organic
substance. In all the cannel coals, traces of these ae
though not so numerous or abundant, can be seen. Mr.
Quekett has even applied this test to Welsh anthracite, in
which substance no rings or fibrous structure can be made out
in sections, yet where, he says, the ash gives unmistakable
evidence of the presence of woody tissue.*

If. Such, then, are the facts which an investigation into the
structure of coals on the one hand, and of the Torbanehill mi-
neral on the other, has elicited. If the account I have given of
them be correct, it must be evident that the differences they
present are marked and distinctive; that the one is essentially
a woody structure, whilst the otheris not. Every kind of coal,
including the brown Methil, may be at once distinguished
from the Torbanehill mineral, by the rings contained in a
well-made transverse section. I further contend that such an
appearance constitutes, in the majority of cases, a practical
and evident test, distinctive of genuine coal, and that by means
of it all kinds of known coal, whether household or cannel,
can at once be distinguished from the Torbanehill mineral.

Now if this be the case, it may well be asked how it hap-
pened that, at the late celebrated trial, so many persons, all of
whom represented themselves as being skilful observers with
the microscope, should have been made to give diametrically
opposite evidence, not only as to matters of opinion, but as to
what appeared to be matters of fact? In endeavouring to
place the remarkable histological controversy which has origis
nated out of the trial of Gillespie versus Russel on its correct
basis, it must be remembered that unquestionable organic
structure is only present in the Torbanehill mineral at certain
places. No one, for instance, can doubt that the scalariform
ducts seen by all parties are of vegetable origin; but it is no-

* ‘Quarterly Journal of Microscopical Science,’ No. VI., p. 43.

192 DR. BENNETT, ON THE STRUCTURE OF

where pretended that these were everywhere present in the
mineral. It is of great importance, therefore, not to confound
the organic plants imbedded in a substance with the substance
itself. The occurrence of Stigmaria or other vegetable remains
in coal, or in the Torbanehill mineral, no more constitute
those substances coal, than they convert sandstone and lime-
stone into coal, in both which rocks they are also found. Nor
do I imagine it can be generally maintained that because
animal substances, such as teeth, jaw-bones, or the skeletons
of fishes and lizards, are occasionally found imbedded in
stone, that therefore they form an essential and necessary
part of the stone itself. At the trial, great amount of
confusion resulted from not keeping this distinction clearly
in view.

Thus when Mr. Quekett stated that all that which may be
supposed like vegetable structure in the Torbanehill mineral
disappears when the structure is thin, he was asked by the
Dean of Faculty, “ When you speak of that which appears as
vegetable structure, you mean those isolated fossil plants?” to
which Mr. Quekett unfortunately answered, ‘ Yes ;” for what
he really meant was, not the isolated imbedded plants, but the
structure of the mineral itself. In consequence, the counsel
for the pursuer and for the defender truly played at cross-
purposes throughout the whole of the structural evidence ;
for, notwithstanding the clearness of Dr. Balfour’s statement,
he was asked, after saying that the mineral consists of a plant,
whether he had seen fossil plants in stone ? to which he an-
swered, Yes. But then being asked whether he considered
that an example of such an appearance, he very correctly, ac-
cording to his views, answered, No.

From the published report of the trial, however, by Mr.
Lyell, it is evident that the eminent gentlemen who contended
that the Torbanehill mineral was a vegetable substance
abounding in cells, did not adopt this idea because various
plants were imbedded in it, but because they believed the
clear rounded masses | have described were themselves vege-
table cells. Unfortunately, the possibility of this theory being
adopted had not been anticipated, nor was it perceived by the
counsel for the pursuer. In consequence, the witnesses on
the one side were made to declare that the Torbanehill mineral
was not vegetable, and on the other that it was, without the
true reason of this discrepancy ever having been made to
appear.

Dr. Balfour stated in court, that he believed the yellow part
of the Torbanehill mineral to consist of vegetable cells; that
it was not the mere impression of a foreign fossil, but the

THE TORBANEHILL MINERAL, ETC. 193

actual structure of the mineral at that place.* In the same
manner Dr. Redfern, when asked,+ ‘ What do you think
these yellow spots indicate ?” replied, ‘“‘ They indicate the
existence of vegetable cells.” The reasons he gave for so
considering them were, ‘That they can be perfectly isolated
—they project upon the edges of all sections of the mineral—
they are rounded—they are as uniform in size as the cells of
other vegetable structures—the general appearance of the sec-
tion is that of a piece of vegetable cellular tissue—the yellow
spots do not act upon polarized light, or act upon it very
feebly.”

Dr. Greville, also, speaking of the same bodies, said,{ that
“he had no more doubt of their being vegetable cells than he
had of his own existence ;” that “in one specimen it was so
unequivocally marked, and so regular, that it might be com-
pared to that of a recent plant;” and that ‘no person accus-
tomed to botanical sections would hesitate in believing it to
be cellular tissue.”

From these quotations it must be evident that both parties
saw the same things, but that while on one side it was con-
tended that they were not vegetable cells, but bituminoid
masses imbedded in clay, on the other it was strongly asseve-
rated, in the language I have quoted, that because they were
vegetable cells, therefore the Torbanehill mineral was a fossil
plant. But in consequence of the reason of this difference in
opinion not having been distinctly brought out in examination,
the greatest confusion seemed to prevail in the minds of judge,
counsel, and jury; and it was thought that the witnesses
for the defender being skilful botanists, were enabled to see
what the witnesses for the pursuers did not see. This result,
as well as the confusion occasioned by the examination of the
witnesses, is evident from the observations made by the learned
Judge to the jury, from which I shall take the liberty of
quoting :—

“One general remark may be made on the microscopic
testimony, and it is, that there are those who see a thing, and
also those who do not see it—those who do see it, cannot see
it unless it is there, and those who cannot see it do not see it
at all. But very skilful persons looking for a thing and not
seeing it, creates a strong presumption that it is not there.
But when other persons do find it, it goes far to displace the
notion that it is not there. But there is another observation
on the microscopic evidence that occurred to me. I do not
know whether I am under any misapprehension, but I think

* Mr. Lyell’s Report, pp. 168-9. T Lbid?,. pel'70.
{ Ibid., pp. 171-2.
VoL. HI. Oo

194 DR. BENNETT, ON THE STRUCTURE OF

that three, certainly two, of those examined by the defenders
are botanists also; and I do not think that any of those ex-
amined for the pursuer, three of them from London, repre-
sented themselves as botanists. Now the defenders’ witnesses
are accustomed to look for plants, and can understand them
when they see them. The gentlemen on the other side, again,
looking for woody fibre or tissue, are not, as I understand,
conversant or skilful in fossil plants.’ *

Now, so far from the botanists seeing what the histologists
did not see, it is nowhere made to appear in their evidence
that they ever observed those rings on a transverse section,
which I have endeavoured to show are distinctive of true coal.
On the contrary, they contended that coal and the Torbanehill
mineral were similar in structure, the elements of the one
existing in the other, both containing vegetable cells; that
the numerous yellow Glens masses bbéervedia in the latter were
in point of fact such cells, and constituted the proof of vege-
table organization.

I think it of great importance to rescue the mode of inves-
tigation by means of the microscope from all reproach in this
case, and to point out that the discrepancy which existed is
not one of fact, but one of inference. I hope then it will be
evident that the true scientifie controversy is altogether con-
nected with the question of whether these yellow masses,
which both parties saw, described, and figured, are or are not
vegetable cells.

Now the view taken up by myself from the first, and whioh
was also taken up by Dr. Adams and Mr. Quekett, indepen-
dently of each other, was that they are not cells, but masses
of a concrete bituminoid or resinoid substance, imbedded in
earthy matter. We could nowhere discover in them any trace
of cell-wall or contents. Their mode of fracture was more
crystalline in its character than anything else; they occurred
confusedly together, and nowhere presented that definite
arrangement to one another, or to ducts and woody tissue,
which exists in plants. Numbers of them present no envelope
or definite boundary, but are scattered through a substance
often more than two feet deep, extending for acres, and it may
be for miles. If these yellow masses be cells, what is their
origin? ‘They cannot come from the woody tissue of the
neighbouring coal, for, as we have endeavoured to show, such
coal is destitute of them. The rings in coal are much smaller
in diameter, are of regular size, ani present the character of a
tube cut transversely, Such rings could never be confounded
with the yellow masses of the Bere: But supposing these

* Mr. Lyell’s Report, pp. 238-9.

THE TORBANEHILL MINERAL, ETC. 195

latter to be cells, could such multitudes of them be derived
from the gigantic ferns of the coal formation, or such as are
imbedded in the mineral? I think not; because the amount
of scalariform and woody tissue is too disproportioned to the
number of the cells to favour such an idea. Besides, what
kind of force or power could have been in operation that would
have separated and collected the delicate cells, and left the
ducts and other tissues of the plants by themselves, and out of
sight throughout such enormous masses. I have carefully
examined the cells in large ferns, and observed the singular
markings of cellular tissue, woody fibre, and scalariform ducts,
many of them present, visible even to the naked eye,—than
which nothing can be more unlike the Torbanehill mineral.
The cells themselves are also larger, of more uniform size, and
contain numerous starch granules; whilst the true resin cells
are exceedingly large and distinct, strongly analogous, indeed,
to what I have described as existing in the woody texture of
coal, but wholly dissimilar to anything observable in the Tor-
banehill mineral. Such a view, indeed, would, it seems to me,
lead to the extraordinary conclusion that this mineral is com-
posed of a vegetable tissue, more cellular than any plant ever
yet met with, recent or fossil, and so rich in cells as to be
wholly dissimilar to what we can even imagine to have existed,
taking its size and bulk into consideration. Such masses of
cells could not have been formed or nourished without ducts
passing through them, in various definite directions, to convey
a nutritive fluid; and yet we find such ducts only to be acci-
dental, and only distinctly connected with plants imbedded
here and there in the general mass.

Whilst, then, the notion of these yellow masses being vege-
table cells, seems to me opposed to every known or conceiv-
able fact yet ascertained to exist in vegetable histology, or
from such as are demonstrable in the Torbanehill mineral, the
theory of their being bituminoid masses imbedded in clay,
appears to be in perfect harmony with all of them, and espe-
cially answers the reasons given by Dr. Redfern.

With a view of determining whether the Torbanehill mineral
could by any possibility be produced by a process similar to
that of the formation of peat, which was described at the last
meeting of the Society by Dr. Fleming,* I have examined
various specimens of peat, and have confirmed his description.
They consist of mosses, especially of the Sphagnum, the spiral
cells of which plant are peculiar, and easily recognised, asso-
ciated with broken-down woody tissue, root-stalks, and

* Proceedings of the Royal Society of Edinburgh. Session 1853-4,
p. 216.

© 2

196 DR. BENNETT, ON THE STRUCTURE OF

bundles of simple ducts, more or less carbonized and con-
densed together. The deeper the peat is taken from the bog,
the more condensed, broken up, and altered these textures
are ; still, however, sufficiently retaining their characters to be
readily distinguishable. The peat of Scotland between this
and Glasgow, and that of the north of Ireland, of which I
have examined numerous specimens, taken from mountain
bog, as well as the flow bog, are identical in structure. One
specimen of peat, however, given to me by Dr. Traill, which
he obtained in Lancashire, andseyiidh answers in description
to what is called Pitch Peat, is blacker in colour, the carbo-
nizing process is more complete, and the vegetable tissues less
distinct. But here and there, in a thin section of this peat,
there exist rounded masses of the same bituminoid character
as are found in the cannel coals and in the Torbanehill mineral.
This fact confirms the theory formerly advanced, that these
bodies are not cells, but a concrete bituminoid substance, pro-
bably derived from the beds of coal in Lancashire, in the
immediate neighbourhood of the peat.

We may therefore conclude that every kind of coal has a
distinctly woody basis, which is easily demonstrated by its
longitudinal and transverse sections; that the cannel coals
have, in addition to this woody structure, a greater or less
number of the bituminoid masses imbedded in it ; and that the
Torbanehill mineral has no such woody texture, but is essen-
tially composed of the bituminoid masses ambeddedi in clay.

Ii]. In the third place, the theory which I am disposed to
put forward as most in harmony with the various facts and
arguments previously stated, is as follows:—Ist, That the
various organic appearances found in the sections and ashes
of coal are explicable by the supposition that coal is wood
chemically altered, and for the most part coniferous wood, or
wood allied to it in structure, because, from a careful compa-
rison of recent fir-wood with the various kinds of coal, I find
the structural appearances of the cellular tissue, resin cells,
and ducts, to be very similar. Further, no fir-wood growing
in this country contains spiral ducts ; and it is remarkable that
no traces of such ducts are to be found in any of the coals I
have examined, Further, the assumption that coal is formed
from fir or allied woods, not only explains its structure, but
accounts for the large amount of bitumen, resin, or inflamma-
ble matter it contains, resin being a well-known abundant
a opy of the coniferous tribe of plants.*

* In the above passage, I have carefully avoided any expression which
oe suggest the notion that in my opinion the wood from which coal is
formed, is exclusively coniferous wood. I believe that, with regard to the

THE TORBANEHILL MINERAL, ETC. 197

2nd, The Torbanehill mineral, although it presents essen-
tially no traces of vegetable structure, is rich in the bituminoid
substance ;—a circumstance, I think, explained by the fact
that it is found in the neighbourhood of coal, so that the bitu-
minoid or resinoid matter formed in the partially-woody struc-
ture of the latter has flowed out, mixed itself with, and
solidified in the essentially earthy substance of the former.
It is easy to conceive how enormous pressure, conjoined with
chemical change and heat, may have effected this, and how
sometimes such fluid bituminoid matter may have run into
neighbouring beds of peat, of clay, or even of sandstone.
Facts, indeed, are not wanting to show that occasionally large
collections of such substance, almost pure, may be formed,
unmixed with either peat or clay, of which the remarkable
specimen I now exhibit to the Society, taken from the Binnie
Quarry, and for which I am indebted to Dr. Christison, is an
example. Fragments of this substance, under the microscope,
closely resemble the yellow masses which exist in the Tor-
banehill mineral.

In conclusion, I would remark that the controversy on this
subject is only an example of a far more extensive one which
is now everywhere taking place throughout the natural sciences,
in reference to the influence which more improved methods
of research in chemistry and histology should exercise on our
thoughts and nomenclature. Those who, with myself, recog-
nise that differences in structure indicate differences in func-
tion, and that these should be studied as the foundation for a
correct classification, will recognise in the question, what is
coal? an analogue to the questions, what is wood or coral ?—
what is bone or tooth ?—what is a fibrous or a cancerous
tumour? The progress of science, and especially of micro-
chemistry, has already answered some of these questions, and
will ultimately determine others; and in doing so, will over-
thr6w the more vague and incorrect views and terms which
previously prevailed. At the trial, indeed, it was very plau-
sibly argued, that, in a bargain between man and man, scien-
tific terms were of no value, and that a whale among whalers
was still a fish.* But in this Society, as no naturalist, con-

varieties and even genera of the plants of the coal-formation, there is still
much to be discovered. But so far as my examinations have gone, the
appearances observed warrant the general inference stated in the text, one
which has also been arrived at by Mr. Quekett. (‘ Mic. Journal,’ No. vi.,
p- 42.) The important fact to be kept in remembrance is, that coal is
fossil or transformed wood, whilst the Torbanehill mineral, and all the
shales which I have examined, are not.
* Mr. Lyell’s Report, p. 231.

198 ON THE TORBANEHILL MINERAL, ETC.

versant with the structure and functions of a whale, would for
a moment suppose it to be a fish, because it inhabits the
water and resembles one; so I contend no histologist, ac-
quainted with the structure and properties of the Torbanebill
mineral, ought to maintain that it is coal, because it is dug
out of the earth and burns in the fire.

( 199 )

TRANSLATIONS.

Osservations on Nocrituca (miliaris?). By Dr. W.
Buscu.*

Tue following observations upon the structure and repro-
duction of a species of Noctiluca were made by Dr. Busch in
the year 1849, and will be found in his work cited below,
which was published in 1851. With respect to the structure
of the animal, they perhaps present nothing in addition to
what has already been made known to our readers in the
Papers by Mr. Huxley and by Dr. Webb, in the present Volume
of the ‘ Journal ;’ but as regards the reproduction and de-
velopment of the Noctiluca, they afford several new points,
and it is for that reason that we have thought it might be
useful here to introduce them, and the more so, as it would
seem these remarks by Dr. Busch had escaped the notice of
Krohn,f as well as of Mr. Huxley t and Dr. Webb.§ The
species noticed by Dr. Busch occurred in great abundance in
the Bay of Malaga, and is regarded by him, but we think,
perhaps, erroneously, as distinct from NN. miliaris. He
terms it NV. punctata, from the circumstance that the integu-
ment was covered with very numerous minute pigment-points ;
but the resemblance of his figure to NV. miliaris is so striking,
and the structure, so far as he describes it, so closely identical
with that of the latter, that no doubt can be entertained as to
the identity of the two forms.

‘* These animals, as is well known, consist of a rounded disc of a gela-
tinous consistence, like that of the Meduse. At the upper part (fig. 1, a,
Pl. X., Mic. Jour.), the borders are curved inwards and downwards, so
that, whilst on the under side the contour is continued uninterruptedly,
a sort of hilus is formed above, from the middle of which a straight, sharp-
bordered rod, 6, extends directly inwards and downwards, being prolonged
into an acute point. At the point where the above-mentioned curved
borders meet is situated a brown, round body, ¢ [nucleus], from which
numerous branched fibres extend towards the periphery. The solitary
motile organ of the animal arises from about the same point. This is a
band-like filament, d, about as long as the diameter of the body of the
creature, and exhibiting numerous transverse lines, which give it a striated
appearance, but never extend across the entire width of the filament. The

* Abstracted from ‘ Beobachtung. tb. Anat. u. Entwickl. einiger wir-
bellosen Seethiere,’ p. 103. Berlin, 1851.

{ Wiegmann’s Archiv., 1852, p. 77.

t ‘ Quarterly Journal of Microscopical Science,’ Vol. iii., p. 49.

§ Ibid., p. 102.

200 DR. BUSCH, ON NOCTILUCA (MILIARIS?).

animal moves this sort of proboscis slowly backwards and forwards.
Opinions are much divided as to whether an opening, or sort of mouth,
exists in this Adlus, or whether the creature is unfurnished with such an
organ.”

Though he has not seen it, the author believes there must
be an entrance.

‘¢ From the few data,” he goes on to say, “afforded by the study of the
development of this curious creature, it may, however, be shown that an
inversion or invagination takes place in this situation, and consequently
that an entrance must exist.

« As regards the interior of the disc; in some individuals it was per-
fectly empty, but in others, several brown bodies existed, as seen in fig. iy,
sometimes of a rounded, sometimes of an oval or hour-glass shape. Occa-
sionally they were in such close apposition with the nucleiform body, that
the latter appeared to be continued into them; but they might also be
noticed perfectly free in the interior. The structure of these bodies is
shown in fig. 8: it represents a cell with homogeneous walls, and contain-
ing a large, coarsely granular nucleus. Among numerous perfect Nocti-
lucce, some were met with composed apparently of nothing but an empty
membrane, and whose true nature could only be recognised from the
presence of the proboscis. In the interior of these sacs were found minute
corpuscles, such as are represented in fig. 2; viz., oval discs, with a
nucleus occupying nearly the whole interior. The colour of these bodies
corresponded with that of the minute globular bodies, which were noticed
in the interior of the old Noctilucce, but from which they were distin-
guished by the homogeneity of the substance of the nucleus. Occasionally,
though more rarely than the above, these sacs contained germs somewhat
farther advanced in their development (fig. 3). The most important
change apparent in these is the existence of a process as yet obtuse.
These bodies occurred more abundantly in the free state, swimming about
among the other Noctilucce, than those contained in the sacewli ; and their
farther development was observed to take place as follows. The obtuse
process becomes pointed, and on its side is formed a minute appendage,
arising from the opaque nucleus, and resembling in structure and relations
the proboscis of the adult animal (fig. 4). It is thence evident that the
nucleus represents the brown nodule in the Ailus of the mature Noctiluca,
and that the motile filament arises from it. It might now be expected
that the round disc simply increased in size, and that the other organs
were developed in its interior ; but it would appear that the entire organism
is subjected to remarkable transformations before this result is attained to.
As the disc increases in size, the pointed process becomes elongated out-
wardly (figs. 5 and 6); and in its interior appears a structure resembling
the ‘rod’ which we have described as existing in the Noctiluca ; but the
direction of the rod at this time is exactly the reverse of that in which
it is placed in the adult animal. For whilst in the latter, starting from
the brown nodular body, it stretches towards the periphery of the disc
farthest from the nucleus, in the former it projects straight out from it.

“At the same time also the border of the disc loses its evenness, and
acquires angular processes of the same colour and consistence as the disc
itself (figs. 5 and 6). Viewing all these figures, it seems most probable
that the form of the large animal is developed out of them in the follow-
ing way. As the disc continues to grow, the ‘rod’ must be reverted on
itself, and the processes of the disc having at the same time become longer
and broader, must close over it and unite. The animal would thus be
perfected; and, upon any other supposition, it is not easy to see how the

DR. BUSCH, ON NOCTILUCA (MILIARIS ?). 201

‘rod’ should come into the proper position ; or what function is performed
by the projecting processes.”

The full elucidation of this very interesting point was pre-
vented by the interference of the highly enlightened port-
officials, who feared that the author’s researches in Marine
Zoology would be injurious to the interests of the Spanish
people.

The fragmentary observations in development made by the
author were too scanty, as he considers, to lead to any de-
finite result. ‘The most important point appears to be
to determine whether the genus found in the empty sacculi
are identical with the brown corpuscles met with in the
interior of the old Noctiluca. From their size, this might
certainly be supposed ; but in that case, the originally granular
contents of their nucleus must be transformed into a homo-
geneous substance. It is probable, therefore, that the brown
bodies, which at first make their appearance on the nodular
mass, may be gemma, which are subsequently detached, and
after remaining for a time in the interior, undergo further
development.” (?)

In fig. 7 is represented an animal apparently referrible to
Noctiluca, and which might readily be imagined to represent
a gemmule fully developed on a perfect Noctiluca, which had
pullulated on the disc itself, and only required to be detached
to become an independent individual. But the author is
rather inclined to believe that it is only an abnormity, a double
monster ; for if a germination of this kind really took place in
this class of animals, it would be very remarkable that only a
single instance of it should be presented, among the innu-
merable multitudes of individuals brought under the author’s
observation.

“ Among the Woctiluce taken during the three days,” in
which he was permitted to continue his researches, ‘“ there
occurred bodies of another kind still (fig. 9), which, like the
Noctiluce, floated on the surface of the water, and were of
exactly the same size and consistence, although they presented
organs of far smaller dimensions. Some specimens also shone
in the dark like the Moctiluce. They were minute gelatinous
discs, nearly perfect spheres, quite transparent, without fibres
or filament ; the greater part of their bulk was entirely homo-
geneous, except that on a very small segment of the upper
surface might be remarked numerous yellowish processes.
Most of these processes were rounded, but some had a very
fine point, into which they were prolonged above, being
attached by a wider base below (fig. 10). The only indica-
tion of structure in them were minute round granules. That

202 DR. COHN, ON THE DEVELOPMENT OF

these bodies were animal existences, is perhaps indubitable,
from their phosphorescence; but in what connexion they
stand with respect to the Noctiluce, associated with which
they occurred in large number, cannot at present be deter-
mined.”

UNTERSUCHUNGEN weber die ENTWICKLUNGS-GESCHICHTE der
MrKRoskKOPISCHEN ALGEN und Pitze. Von Dr. F. Conn.
(Researches on the Development of the Microscopic Alge
and Fungi. By Dr. F. Cohn; pp. 153; 6 Plates. Bonn,
1854.

Tue importance of the study of unicellular organisms, as
leading in the most ready and complete way to a knowledge
of the “ cell,” the foundation of all scientific acquaintance
with the real nature of plant life is so obvious, as to have
attracted a great number of followers.

The fresh-water Algz, especially, afford abundant and
readily attainable materials for this study, and have, conse-
quently, formed the subjects of numerous writings. Amongst
those who have distinguished themselves in this field, the
name of Dr. Cohn will ever be held in deserved honour.
He has, for many years, as he says, devoted himself to this
study; and, especially, to the remarkable propagation of
most of these Algz by means of motile cells (swarm-spores) ;
a mode of reproduction which has been observed in most of
the fresh-water species. [he same phenomenon has also at-
tracted the attention of numerous other observers, and been the
subject of several memoirs. Among the more important of
these, exclusive of Dr. Cohn’s, may be noticed the observations
respecting it contained in Dr. Braun’s remarkable work on
‘ Rejuvenescence in Nature,’ of which a translation by Mr.
Henfrey has lately been published by the Ray Society; and
the ‘ Recherches sur les Zoospores des Algues et les Anthé-
ridies des Cryptogames’ of M. Thuret. The appearance of
these independent memoirs appears to have turned Dr. Cohn
from his original intention of publishing a special treatise on
the ‘Swarm-cells of the Algz,’ and to have decided him
merely to give separate essays on those points appearing to
him to demand further attention ; his former monograph on
the ‘ Development of Chlamydococcus (Protococcus) pluvialis,’
of which an abstract has also been published by the Ray
Society with figures; and his Memoir in Siebold and
Kolliker’s Zeitschrift f. wiss. Zool. ‘ On a new genus from the
family of the Volvocina,’ of which a translation has appeared
in the ‘ Annals of Nat. History,’ 2nd series, Vol. x., p. 321,

MICROSCOPIC ALG AND FUNGI. 203

are the more important of these essays that have yet appeared,
and should be attentively studied by all who are desirous of
becoming acquainted with the matter.

The present work is, in fact, a collection of shorter essays
having more or less direct riecenne to the same subject, and
will Ee found to contain a vast amount of important and
interesting information.

The subjects treated of are—

1. On the relation of the microscopic Fungi to the microscopic Alge.

2. On Chytridiwm, and some allied genera.

3. Observations on Goniwm pectorale, and the Volvocina in general.

4, On the propagation of Hydrodictyon utriculatum, together with
some remarks on ‘‘ swarm-cells ” in general.

On the germination of Zygnema and Anabeena.

Ou

These papers are illustrated by figures of

Anthophysa Miilleri. Zygnema stellinum.
Zoogleea (vibrio) termo. Closterium Lunula.
Spirulina plicatilis (Spirochete, p., | Mougeotia genuflexa ?

Ehr.) Anabeena intricata ?
Spirulina Jenneri. Achlya capitulifera.
Synedra putrida, un. s. Chlamydococcus pluvialis.

Chlamydomonas hyalina (Polytoma | Goniwm pectorale.
uvella, Ebr.) Chlamydomonas pulvisculus.
Chytridium globosum, A. Braun. Hydrodictyon utriculatum.

Peronium aviculare, Cohn. (dogonium capillare.
Achlya prolifera. | Cladophora glomerata (monstrous
Spirogyra nitida, | spores of ),

1. On the relations of the microscopic Fungi to the micro-
scopic Alge.

The result of his study of the lowest forms has led Dr.
Cohn to the conclusion, that no sufficient reasons derived from
morphological and developmental considerations exist for the
separation of the Alga from the Fungi. Though the distinc-
tion between the Thallophytes and Cormophytes of Endlicher
is sufficiently definite, the three classes into which the former
have, since Linnzus, been subdivided, viz., the Alge, Fungi,
and Lichens, are by no means so well defined as, for instance,
the Mosses from the Ferns, or the Equisetacee from the
Lycopodiacee. It would seem as if the multitudinous class
of Thallophytes constituted, organologically, but a single
indivisible kingdom, and shat Mthetlinwe| dined provinces
were characterized merely by the more or less developed, and,
it must be confessed, widely different forms, and in no way
by any intrinsic difference of type in the vegetative or repro-
ductive organization.

The Alge, as usually understood, like most other plants,
are capable of appropriating, by an innate power, the materials

204 DR. COHN, ON THE DEVELOPMENT OF

requisite for the maintenance of their organism, from the
elements carbon, oxygen, hydrogen, and nitrogen, and some
oxides and salts, which are afforded to them in the surround-
ing medium, in the form of carbonic acid, ammonia, and
water ; they do not, therefore, require any organic nutriment,
but are enabled to vegetate in pure water ; they can decompose
the water or the carbonic acid, and evolve oxygen in the
sunlight, acquiring at the same time a green or red colour,
from the development of chlorophyll or some analogous
colouring matter. The Fungi, on the other hand, like
animals and most parasitic plants, have not the power of
spontaneously producing, from inorganic nutriment, the
materials requisite for the maintenance of their vital pro-
cesses—these must be afforded to them in the form of already
organized compounds; they cannot, therefore, flourish where
this nutriment is not afforded to them, either in a living or in
a dead and decaying organism, or at any rate in water in
which a considerable amount of organic matter is not dissolved,
as in an infusion; they evolve no oxygen, and do not become
green in the light. Partly, from the latter circumstance,
Nageli distinguishes the Fungi from the Alga by the want of
chlorophyll, or some analogous colouring matter. But that
the presence or absence of chlorophyll affords no sufficient
character to distinguish the one class from the other, is suffi-
ciently obvious, when we consider the variableness exhibited
in this respect, in several classes of plants, especially in those
of parasitic habits, many of which, it is true, are colourless,
but others, such as the Santalacee, Rhinanthaceze, and Loran-
thacez, have chlorophyll in abundance ; whilst others again,
not of parasitic nature, or not known to be so, as many of the
Orchids, are colourless. The presence also, of chlorophyll in
many of the ‘ Protozoa, as Hydra viridis, Bursaria viridis,
&c., is sufficient to indicate the uncertainty of any character
thence derived. The circumstance of the plants growing in
water, or in the air, has been employed to distinguish the
Alge from the Fungi—it being stated that the former inhabit
water, and that the latter flourish only in the air; but that
this distinction is untenable is at once obvious, when it is
remembered that it often happens that of species even in the
same genus, as Vaucheria, Ulothrix, Protococcus, &c., some
vegetate in water and others in the air.

The difficulties which attend the separation of the lower
Alge and Fungi have led several authors, as Kiitzing, to
propose, for some of them, the erection of a group termed
Mycophycee, under which he includes those Thallophytes
which agree with the rest of the Fungi in their vital con-

MICROSCOPIC ALGAX AND FUNGI. 205

ditions, and consequent want of colour, and are only distin-
guished from them by the unessential circumstance of their
living in water. But a close investigation of the genera
included under the above term, will show, beyond any doubt,
that nearly all the forms of water-fungi are so closely allied
to algan genera, that, with the exception of their wanting
colour, scarcely even a generic distinction can be drawn
between them, and much less one of family.

Thus the only difference between Hygrocrocis, a so-termed
water-fungus, and Leptothrix, consists in the circumstance
that the immotile filaments of the latter contain phycochrom,
whilst in the other the contents are colourless. But whilst
Leptothrix is, perhaps, inseparable from some forms of
Oscillaria, notwithstanding the motility of the latter, so in
the same way do the colourless immotile filaments of the
genus Beggiatoa come under the class of water-fungi, close to
the various forms of Hyyrocrocis. It has already been
remarked by Nageli that the yeast-fungus corresponds in
form and mode of germination with the algan genus Hrococcus,
Sarcina is morphologically identical with Chroococcus, and
that, in its vegetative and reproductive condition, Achlya
corresponds with Valonia or Bryopsis.

With respect to the genus Stereonema, Kutz., Dr. Cohn
proceeds to show that the filamentous growth so named, is
not an Alga or Fungus at all, nor in fact any kind of inde-
pendent organism, but that they are the stems of an infusorium
—the Anthophysa Miilleri, Bory.

The bunches of apparent spores at the extremities of these
filaments are regarded by Dr. Cohn, though apparently not
without hesitation, as identical with the Uvella uva of Ebren-
berg; and, consequently, they are in his view to be looked
upon as belonging to the animal kingdom, for he seems, like
many other German observers, still to adhere to the exclusively
animal nature of many of the Ehrenbergian Monadina.

The loss thus inflicted upon the vegetable kingdom by Dr,
Cohn, is, however, compensated by the addition to it of part
at least of the Vibrionta. The animal nature of these minute
creatures has, hitherto, never been disputed; but Dr. Cohn
sees reason, and affords what appear to be good grounds for
it, to believe that several forms of the Vibrionia may be
certainly shown to belong to the vegetable kingdom.

The form which seems to have constituted the principal
subject of Dr. Cohn’s researches in this respect, is that known
as Vibrio lineola, Ehy., but which was separated from the other
Vibriones by Dujardin, under the name of Bacterium termo.

The result of his investigations is, that the corpuscles of

206 DR. COHN, ON THE DEVELOPMENT OF

Bacterium termo, Duj. (Vibrio lineola, Ehr.), represent the
developmental condition of a plant ; that they are, in fact, the
liberated, self-motile cells (swarm-spores) of a Mycophycean,
closely allied, morphologically, with Palmella and Tetraspora.
He has been unable, however, as yet to discern any motile
cilia in them. He proposes a new name for this form—
Zooglea, with these characters,

Cellule minima, bacilliformes, hyaline, gelatina hyalina in massas
mucosas globosas, uveeformes, mox membranaceas consociate, dein singula
elapse, per aquam vacillantes.

Syn. Palmella Infusionum, Ehr. ; Micraloa teres, V. Flotow ; Bacteriwm
termo, Duj.; Vibrio lineola, Ebr.

The general results of his researches on the subject of the
Vibrionia are thus summed up.

1. The Vibrionia all appear to belong to the vegetable kingdom,
since they exhibit an immediate, close relationship with manifest
Alge.

2. From their want of colour, and their occurrence in putrifying
infusions, they belong to the group of AZycophycece.

3. Bacterium termo is the motile swarming form of a genus (Zoogleew)
closely allied to Palmella and Tetraspora.

4. Spirochete plicatilis belongs to the genus Spirulina.

5. The elongated, motionless vibriones (V. bacillus, &.) are allied to
the more delicate forms of Beggiatoa (Oscillaria).

6. The shorter Vibriones and Spirilli correspond, in form and in
their movement, with the Oscillarice and Spiruline ; but no
definite opinion can be given as to their true nature.

The relationship of the Oscillariz with the Vibrionia was
noticed even by the earliest observers. Thus O. F. Miiller
termed a Spirulina, Vibrio serpens; nor has the analogy
between them been overlooked by Ehrenberg and Perty.

Dr. Cohn goes on to describe the great resemblance between
Ehrenberg’s Monas prodigiosa, the cause of the phenomenon
termed “ blood in bread,” and Bacterium or Zooglea termo.
The main difference between the two consisting in the shape
of the former, which is more spherical or ovoid than bacilli-
form, and its purple-red colour.* Allied with this are the
masses of Vibriones, which, according to Mitscherlich’s
observation, appear on rotten potatoes, as a kind of ferment,
and have the power of dissolving cellulose (Monatsh. d. B.
Ak., March 1850). All these forms appear to be closely
allied to Zooglea termo, if not generically identical with it.

According to Cohn there is not the slightest difference
between Polytoma uvella, Ehr., and Chlamydomonas pulvisculus.

The general summary of his inquiries may be thus stated—
That most of the Mycophycee, agree in family, and even in

* Upon this subject vide Fresenius, ‘ Beitrage zur Mycologie.’ Part I.

MICROSCOPIC ALG AND FUNGI. 207

genus with certain fresh-water Alga. Whence it follows that
that class in general is not a natural group, but an assemblage
of plants of various natural families and genera, joined
together by a single artificial character.

In this way the Cryptococcacee will be arranged under the
Palmellacee ; the Septomitez, under the Oscillariee and
Septotrichee ; the Saprolegniee under the Vaucheriee ; some
genera would be abolished altogether, such as Hygrocrocis,
whose species must be regarded as colourless species of
Leptothriz, and those of Beggiatoa as colourless Oscillarie :
and as Spirochete, which is identical with Spirulina plicatilis ;
Vibrio bacillus would probably be termed Oscvllaria bacillus,
&e,

2. Cohn’s observations on the subject of Chytridium and
some allied genera are of particular interest in several respects,
and especially with reference to the important matter of the
connexion between parasitic Fungi and certain diseased condi-
tions in plants. ‘The extraordinary prevalence, of late years, of
epidemic diseases attacking nearly all cultivated plants, and
many of which have been observed to be accompanied with
the development of Fungi, renders the determination of the
true relations of the one to the other a point of extreme
interest and importance, not only in a scientific, but also in an
economical sense. ‘lo the ancient and well-known pests of
‘rust’ and ‘ smut’ have been added, it may be said, within
a few years, the more destructive potato—and vine—cisease ;
but other important cultivated plants, as the olive—orange—
beet-root, as well as timber-trees, belonging to the Coniferous
family especially, have also suffered in a similar way.

Disease of this kind has been by no means confined to
cultivated plants—these epidemics are not limited to plants
useful to mankind—their ravages may be witnessed among
the useless and noxious members of the vegetable kingdom,
to an almost equal extent with the highly-prized objects of
human cultivation.

A remarkable instance of this is afforded in the present
Memoir of Cohn. And his observations will go very far to
solve any remaining doubts as to the true nature of the
relations between the parasite and the disease. Inasmuch as
the victim and the destroyer are both plants of the simplest
kind—in fact, unicellular alga, in which the whole process of
the invasion and its effects is plainly submitted to the eye.
The main question to be determined is, whether the fungus is
to be regarded as the cause of the disease, or whether the
disease is, as it may be termed, the cause of the fungus. In
the former case, the appearance of the Fungus or its spores

208 DR. COHN, ON THE DEVELOPMENT OF

would be seen to precede the outbreak of any morbid pheno-
menon, and in the latter, the reverse would be observable.
Other influences of a more general, external, chemical,
physical, or it may be, cosmical nature, must, doubtless,
concur, to render the disease, however produced — truly
epidemic—but these are not now the subject of inquiry.

The decision of the question as above stated is obviously
extremely difficult, if not wholly impossible, in the higher
plants, owing to the complexity of their structure, and the
inability we labour under of tracing microscopically the entire
course of the disease, from its first appearance to its termina-
tion.

An observation, therefore, which Cohn states, he made in
the year 1852, of a disease attacking unicellular plants, is of
the greatest interest ; he observed a sort of epidemy to break
out among some Desmidew which he had kept in a flourish-
ing condition for some time. The consequence was, that the
Closteria, especially, were nearly all destroyed with great
rapidity. He discovered that the cause of this remarkable
epidemic was a peculiar microscopic plant, which attached
itself to healthy Closteria, living at their expense, and con-
suming or destroying their living contents, and thus killing
sthem. The unicellular nature of the victim and of its de-
troyer allowed the whole proceeding to be observed through-
out all its stages ; and thus, at any rate, one certain fact was
established with respect to the significance of epiphytes in
epidemic diseases.

The matter is thus described :—“ In the beginning of
April he observed upon the dead Closteria of every species,
spherical vesicles of very various dimensions, the smallest
being scarcely 1-300", and the largest more than 1-50" in
diameter. These vesicles were filled with opaque, fine-gra-
nular but colourless contents. They were seated either
singly, or in larger or smaller numbers upon the cell-wall ;
on some Closteria as many as twenty might be counted.”
The granular contents of the vesicles were seen to become
gradually transformed into motile spores or ‘ swarm-cells,’
which escaped through openings or perhaps ruptures of the
parent vesicle, and moved about very actively in the water by
means of a single cilium. When all had escaped, the vesicle
was left as a colourless, hyaline membrane.

The spores themselves resembled in shape the minute
monades, and equally resembled the ‘swarm-cells’ of Achlya
prolifera, but from which they differed in their very remark-
able motility. From this, and from their correspondence in
form and size, Cohn regards it as probable that these Chytri-

MICROSCOPIC ALG AND FUNGI. 209

dium-spores may be identical with Bodo saltans of Ebren-
berg.

These ‘ swarm-cells’ continued to move about in the water
until they reach a situation suited for their further develop-
ment,—that is to say, until they arrived at a new Closterium.
And, what was especially remarked, they invariably attacked
a perfectly-healthy, brishly-vegetating individual, in which the
green endochrom was in close opposition with the cell-wall.
Having attained to its goal, the spore enters into a new stage
of development—it becomes quiescent, affixes itself, and begins
to germinate ; that is to say, the ciliwm disappears, and the
spore, surrounded with a rigid membrane, assumes the aspect
of a spherical, colourless cell, whose opaque nucleus is still
distinctly recognizable, in close contact with the membrane
of the Closterium.

The ‘swarm-spore’ now rapidly expands into a large
vesicle. The nucleus undergoes a remarkable change ; it
disappears, and is replaced by a highly-refractive drop of
fluid, probably oil, which at first occupies the greater part of
the cell; this drop divides into two, then into several, and
ultimately breaks up into numerous granules or droplets.
When the vesicle has reached a diameter of about 1-100",
its contents are seen to be divided into two portions—a
darker placed on the side at which the vesicle is attached, and
a lighter at the outer periphery. The former, or dark portion,
is produced from the metamorphosis of the nucleus, and con-
sists of numerous larger or smaller granules. This darker or
granular part of the contents gradually increases at the expense
of the other, until at last the whole cell is filled uniformly
with it. When this has taken place, the reproduction com-
mences, the granular contents of the vesicle being broken up
into a vast number of spores, by which the parent cell is
completely filled, as is the case in P2lobolus and other Mu-
corineew. In most of the fresh-water Algz, however, the
development of spores takes place in the protoplasma lining
the wall of the cell.

The parasitic growth thus described, belongs to the genus
Chytridium, instituted by A. Braun in his Work on ‘ Reju-
venescence in Nature.’*

The most important point, however, is with respect to the
influence exerted by the Chytridium, in the course of its
development upon the Closterium.

When the ‘ swarm-spore’ has reached a certain size, the
contents of the Closterium begin to exhibit a morbid change.

* Translated by A. Henfrey, and published by the Ray Society in a
volume of Botanical and Physiological Memoirs, p. 185. A collection of
great value to the microscopical observer.

VOL. IIT. P

210 DR. COHN, ON THE DEVELOPMENT OF

The primordial utricle retreats from the wall and contracts,
expelling the water from its interior. The peculiarly-arranged
Chlorophyll is detached, and begins to be discoloured ; at the
same time, the two vacuoles, filled with granules at each end of
the Closterium, disappear ; ultimately, the cell appears colour-
less and empty, merely some remains of the chlorophyll
being left, in the form of an irregular contracted saccular
mass or masses in the middle of it. That this morbid change
of the cell-contents is due solely and wholly to the influence
of the parasite, may be shown beyond all doubt. For the
contraction of the primordial sac begins at the spot where the
Chytridium spore was attached ; and according as the parasite
has germinated at the middle of the frond, or at one or other of
the ends, it is there that the contents first appear to suffer.

It is clear, therefore, that the Chytridium is nourished at
the expense of the Closterium ; and it may readily be con-
ceived, that a parasite of this kind may produce a most de-
structive epidemy among the millions of inhabitants in a
glass of water, when it is considered that each Chytridium
may contain 4,000 motile spores, each of which is capable of
destroying a Closter‘um, and after a few hours may itself
reproduce the same number of spores.

As regards the mode in which the fatal influence of the
Chytridium is exerted, it would seem to consist not simply in
an endosmotic action through the walls of the two cells, but
by means of a kind of radical fibres which insinuate them-
selves into the Clostertwm, and which may probably be re-
garded as equivalent to the mycelium of a fungus. Dr. A.
Braun (I, c.) expressly describes these radical fibres, as they
appear to have occurred several times to Cohn’s observation,
who has given figures of what he saw. It would thence
seem, that the Chytridium-vesicle is attached to its organic
basis, not simply by adhesion, but by a myceloid tissue,
which penetrates the membrane of the Clostertum, and ramifies
in its interior.

The systematic position of this parasitic fungus, for such it
must obviously be regarded, unless all the Mycophycee are
merged in the Algan order, is clearly in that order, in the
family of the Saprolegniez, itself a section of the Vaucheriee.

With respect to the relations of the ‘swarm-cells’ of the
aquatic fungi to the monades. Just as the green ‘swarm-
cells’ of the true alge so closely resemble certain astomatous
green infusoria, that it is impossible in many cases to deter-
mine whether a doubtful form belong to the animal or to the
vegetable kingdom ; so do the colourless monads in form and
colour precisely correspond with the colourless ‘ swarm-spores’
of the Mycophycee. It is even probable that the number of

MICROSCOPIC ALG AND FUNGI. y Ald

motile cilia is the same in each group; for whilst all green
swarm-spores have at least fwo cilia, the colourless monads
and the swarm-cells of Chytridium certainly have but one ;*
in Achiya also, Pringsheim observed but one, which accords
with Cohn’s own observation, though Thuret and De Bary
assert positively that they have seen two.

To this it may be added, that a great part of the Infusoria,
and in fact not merely of the lowest, but also of those standing
comparatively high in the scale, enter into a quiescent state,
in which they lose all perceptible vestige of movement and
organization, and become invested with a rigid, perfectly-
closed membrane ; apparently in precisely the same way that
vegetable swarm-cells, when germinating, secrete a tough
cellulose-membrane. And in particular, do the true monads
present a condition of encysting, in which they cannot be dis-
tinguished from colourless, quiescent (fungus-) cells. Conse-
quently, since neither the ‘ swarm-cells’ of the aquatic fungi
exhibit any tenable criterion by which they can be distin-
guished from monads, nor the encysted monads any by which
they can be distinguished from the germinating aquatic fung?,
there is no wonder that, in many cases, it is almost impossible
to determine to which category a given organism may belong.

Cohn, however, seems still indisposed to regard all the
Ehrenbergian monads as developmental states of fungi, as he
has convinced himself, he says, of the correctness of Ehren-
berg’s observation, that many, even very minute species, when
kept for some time in coloured water, take up particles of
indigo. This circumstance, Cohn regards as sufficient proof
of the existence of a mouth, and consequently, of the animal
nature of the organism ; in neither of which points, however,
do we coincide with him.

3. The family of the Volvocina affords so many points
of interest and importance, that the study of it may, to a cer-
tain extent, be regarded as a fundamental basis for the know-
ledge of microscopic organisms in general,

The vegetable nature of these organisms, first distinctly
recognised by Siebold, and at present admitted by nearly all
observers, has already been copiously discussed in the pages
of this Journal, and the subject need not here be further
adverted to.

The Volvocina, in general, may be said to consist of two
parts, a colourless hyaline investing cell (Hiillzelle), consist-

ing of cellulose [?|, and of green primordial cells; The
* In Huglena, however, which is deeply coloured, there is but one
cilium.
+ For the explanation of these terms, vide Cohn, Protococcus pluvialis
(‘ Botanical and Physiological Memoirs,’ published by the Ray Society,
1853).

p 2

212 DR. COHN, ON THE DEVELOPMENT OF

latter vary in number, from one to any number in the same
envelope, being single, for instance, in Chlamydococcus ( Proto-
coccus) and Chlamydomonas, eight, as in Stephanosphera, or
innumerable, as in Volvox. In either case, the primordial
cells present the character of simple primordial sacs, which
are not immediately surrounded by any rigid cellulose mem-
brane; consisting merely of a fine-grained protoplasm, co-
loured red or green by chlorophyll, or a peculiar oil, and often
prolonged into mucoid filaments. The primordial cells
themselves are produced peripherally into a colourless point,
from which arise two vibratile filaments, which penetrate the
investing sheath through two openings, and project into the
surrounding water. The reproduction is effected by the divi-
sion of all, or, as in the case of Volvox, of some of the pri-
mordial cells, which, in this case, come eventually to resemble
the parent organism; or the contents of the germinating
primordial cell are more minutely subdivided into motile
zoospores of much smaller size (termed microgonidia), whose
ultimate destination is unknown ; the other or larger form are
termed macrogonidia. The latter, lastly, may assume the

‘ quiescent’ state, each primordial cell within the delicate
‘ investing membrane’ secreting around itself a second, more
dense pailiece membrane, whieh is not perforated by the
motile czlia, but is in close opposition with the primordial cell,
just as in the common plant-cell the cellulose membrane
encloses the primordial sac or utricle. In this, manifestly
vegetative, protococcus-like condition, the cells may remain
torpid and without any movement for almost any length of
time, until their dormant energies are re-awakened by the
addition of water. It would even appear that in many cases,
a previous desiccation is required, to render these winter-
spores capable of germination. (These winter-spores, in dif-
ferent states in Volvox, have been supposed by Mr. Busk to
be represented in the forms termed V. awreus, and V. stedlatus.)

In speaking of Goniwm, a genus referred by Cohn to the
Volvocina, he remarks, that his own observations have led him
to perceive that its structure is somewhat more complex than
it is usually described as being.

In the first place, the entire tablet is surrounded by a
perfectly colourless, transparent envelope, presenting the form
of a flattened spheroid, the axis of rotation being shorter than
the other two, This envelope is not surrounded by any firm
or cellulose coat, and appears to be simply gelatinous or
mucoid; and it is, consequently, not very readily visible.
As in Giher similar cases, it is best brought into view by the
addition of some colouring matter to the water. The green
globules are simple or primordial cells—properly of an

MICROSCOPIC ALG AND FUNGI. 213

octagonal shape, or of a quadrate form with truncated angles ;
and each of the sixteen cells is enclosed in a colourless,
hyaline, delicate, but at the same time rigid membrane.
Cohn, however, has hitherto been unable to determine
whether this tunic contain cellulose or not. The polygonal
gonium-cells, thus surrounded by a rigid membrane, are in
contact with each other at the angles formed by the trans-
parent, colourless wall, and these conjunctures have been
variously understood by different writers. Such as ‘ brides
blanches muquenses contractiles,” of Turpin, and _ the
‘“‘ hand-formed, tendril-like connecting tubes,” of Ehrenberg.
In other respects, the gonium-spores resemble the usual
‘ swarm-spores,’ like which, they contain chlorophyll vesicles,
starch, &c. They also present a variable number of spaces
or vacuoles, filled with water, which are sometimes so
numerous as to give the contents a frothy, vesicular aspect.
With these variable vacuoles, however, must not be con-
founded one, two, or three constant, sharply-defined vesicular
spaces, situated close to the origin of the vibratile cilia. The
reproduction is effected in the usual way by the division,
several times repeated, of the contents of the cells. Into the
particulars of which, resulting as it does in Gonium in the
production of sixteen cells, Cohn enters at considerable
length. He then proceeds to discuss the relation of Gonium
to other Volvocine, and shows, notwithstanding some dis-
crepancies, that it may properly be there placed.

After this, he returns to the subject of the vacuoles in
the Gonium-cells, and carefully distinguishes the vacuoles,
formed apparently by watery secretions in the protoplasma,
such as may be observed in all plant-cells, especially
when young, from others of a particular kind. In Gonium,
he observed two or three vacuoles which disappeared and
reappeared periodically or rhythmically at short intervals—
and which he thence terms contractile vacuoles. He states
that these vacuoles are always placed near the point of
insertion of the vibratile cilia, and that they contract
alternately at regular intervals of so many seconds. Con-
tractile vesicles of precisely-similar kind have been observed
in numerous znfusoria, and were even seen by Ehrenberg long
ago, in the zoospores of Gonium and of Volvox, who entertained
the extravagant notion that they were seminal vesicles. Re-
ferring to these facts, Dr. Cohn, however, imagines that he was
the first to discover the rhythmical nature of the contractions of
these vacuoles, and enters at very great length, and in great
detail, into an account of his observations. Not beimg aware,
we presume, that he was anticipated by more than a year in

t
914 DEVELOPMENT OF MICROSCOPIC ALG AND FUNGI.

this discovery, by Mr. Busk,* who noticed the fact of the
existence of rhythmical contractions in the single vacuole in
the zoospores of Volvox globator. But the most remarkable
circumstance connected with this is the apparently precise
resemblance of the phenomenon in the two cases. Mr. Busk
states, that in Volvox the contractions occur very regularly at
intervals of 38’ to 41’” ; and Cohn’s observations would show
that where two vacuoles exist in the same cell, the interval
for each vacuole varies between 25'” and 48’; and in a case
where but one existed, as in Volvox, the intervals, by observa-
tion, were 45, 43, 45, 42, 43, 40, 42, 41,41". The suddenness
of the contraction, and the gradual expansion of the vacuole,
are noticed by both observers ; in fact, the observations agree in
every particular, save only in the circumstance of the situation
of the contractile vacuole or vacuoles. Cohn says that he
always found them to be situated at the base, as it were, of
the cilia—whilst Mr. Busk states that, “it may be situated
in any part of the zoospore, or not unfrequently in the base,
or even in the midst of one or other of the bands of proto-
plasm, connecting it with its neighbours.”

This rhythmical contraction is, certainly, a remarkable
phenomenon in the vegetable kingdom, and worthy of attentive
consideration, It does not, as yet, appear to have been
observed, except in the above two instances, but will, doubt-
less, be found to exist in much more numerous cases.

4, The observations on Hydrodictyon do not appear to
contain more than a very good summary of what is known on
that subject, and are illustrated by good figures. We shall
return at a future opportunity to this, perhaps, most interest-
ing of all vegetable productions. Upon which will also be
found very valuable information in A. Braun’s work, above
referred to. At the conclusion of this part of his work, Dr.
Cohn propounds the following axiom :—-That in the lowest
forms (fresh- -water alga) a noite! primordial cell, is at the
same time the seat of germination (swarm-spore), whilst in
the higher cryptogamia, it is the fertilizing organ (swarm-
filament) ; on the other hand, in the Vals a quiescent cell
(spore) is the seat of germination, whilst in the highest
phanerogams, an equivalent cell (pollen-cell) discharges the
function of a fertilizing organ,

5. The observations contained in this part of the book
relate to the germination of Zygnema and Anabaina. They
are of considerable interest, and will, with the preceding,
form the subject of a future notice or abstract.

* Transactions of the Microscopical Society. ‘ Quarterly Journal of
Microscopical Science,’ Vol. i., p. 31.

REVIEWS.

PRINCIPLES OF COMPARATIVE PHYSIOLOGY. By W. B. Carpenter, M.D.,
F.R.S. Fourth Edition. London. Churchill.

AxrnouGH it be an ample apology for the use of the micro-
scope, that he who records a new observation by its aid has
added another fact to science, yet we would fain hope that all
who use this instrument are more or less impressed with the
truth, that by its employment large departments of human
knowledge are being moved on. If we wanted an apology for
the use of the microscope, we could not do better than point
to the works of the learned and laborious President of the
Microscopical Society on the various branches of the great
science of Biology. Let any one compare the manuals of
Physiology that were in use twenty-five years ago with the
last editions of Dr. Carpenter’s beautiful volumes, and they
will see not only how our knowledge of the laws which govern
vital phenomena has advanced, but they will see that it has
been mainly by the aid of the microscope. They will see too
in Dr. Carpenter’s volumes how the labours of the humblest
observers become in time part and parcel of the great body
of special and general facts, which constitute the principles of
science. This should be an encouragement to all to persevere
in a course of observation, and to record what they have ob-
served. Few perhaps know the whole value and significance
of the facts which are presented to their senses ; but if they
record them, they become appropriated by those whose special
and peculiar gift it is to generalise, and thus to give a form
and body to science. Of modern writers and workers few
possess this gift to so great an extent as Dr, Carpenter, and he
may be justly regarded as the most successful exponent of
Physiological science in this country, and one of our most
elegant scientific writers. The volume, whose name stands
at the head of our article, is intended as a companion to two
others, the ‘ Principles of Human Physiology’ and the ‘ Prin-
ciples of General Physiology.’ The latter work, which is not
yet published, together with the present volume, formed the
basis of the author’s ¢ Principles of Physiology, General and
Comparative,’ which will henceforth cease to appear as a
single volume.

In the present volume, which is devoted to the department
of comparative anatomy and physiology, the author has

216 DR. CARPENTER, ON COMPARATIVE PHYSIOLOGY.

evidently taken the greatest pains to bring it up to the
standard of knowledge of the present day. We are glad to
find no indications that the author is inclined to rest on his
wide-spread reputation and the popularity of his works, but
that he has_in every department laboured to give the fairest
possible exposition of his science. The principal additions
and alterations in this volume, as we learn from the author’s
preface, occur in relation to the water-vascular system of
some animals, and the sexuality of Cryptogamic plants. We
subjoin Dr, Carpenter’s account of the water-vascular system,
as its existence and peculiarities have been determined by
the aid of the microscope.

It is among the Vermiform members of the articulated series, that we
find the ‘ water-vascular’ system acquiring its highest development. But
it will be desirable first to study it under the simpler form it presents in
the Rotifera, which have no rudiment of a sanguiferous system, the chyl-
aqueous fluid of the general cavity of the body being the medium alike
for conveying nutriment to the solid tissues, and for effecting respiratory
changes in them. On either side of the body of these animals, there is
usually found a long flexuous tube, which extends from a contractile vesicle
(common to both) that opens into the cloaca, towards the anterior recion
of the body, where it frequently subdivides into branches, one of which
may arch over towards the opposite side, and inosculate with a correspond-
ing branch from its tube. Attached to each of these tubes are a number
of peculiar organs (usually from two to eight on each side) in which a
trembling movement is seen, very like that of a flickering flame ; these
appear to be pear-shaped sacs, attached by hollow stalks to the main tube,
having a long cilium in the interior of each, attached by one extremity to
the interior of the sac, and vibrating with a quick undulatory motion in
its cavity ; and there can be no doubt that their purpose is to keep-up a
continual movement in the contents of the aquiferous tubes.—Similar
lateral vessels, furnished internally with vibratile cilia, and often ramify-
ing more minutely (especially in the head and anterior part of the body)
are found in many of that group of Vermiform animals, clothed over the
whole surface of their bodies with cilia, to which the designation Twrbel-
laria has of late been given. These vessels have been commonly regarded
as sanguéferous ; and it is certain that the fluid which they contain is
sometimes coloured, like the (so-called) blood of Annelida; but it is
certain, also, that they have usually, probably always, external orifices,
these being sometimes numerous. In Nas, instead of actually opening
into the cloaca, one set of them comes into close relation to the rectum,
the interior of which is richly ciliated ; thus reminding us of the parallel
distribution of the tracheal system in the larva of Libellulide. In fact,
it seems not improbable that the ‘ water-vascular’ system of the lower
Articulata (which are all aquatic) is the homologue of the tracheal system
of the air-breathing Myriapods and Insects; and that, where it does not
convey water directly introduced from without, the fluid which it contains
is specially subservient to respiration, establishing a communication be-
tween the aerating surface and the tissues of the body generally. There is
an almost complete absence among the Twrbellarice of any more special
respiratory organs. The whole tegumen of the body, being soft and
clothed with cilia, is probably subservient to this function; but there are

DR. CARPENTER, ON COMPARATIVE PHYSIOLOGY. 217

occasionally to be observed about the head (as in Nemertes) particular
groups of cilia longer and more closely set than the rest, reminding us of
the ‘ wheels’ of the Rotifera.

This ‘ aquiferous’ system of vessels presents its greatest complexity and
most elevated character in the group of Entozoa ; whilst at the same time,
there are certain types even of that class, in which it exists under its most
simple and least doubtful aspect. It is only, in fact, by tracing it through
its principal forms and gradations, that the real import of some parts of this
system can be ascertained. In the Cestoid worms, we find four principal
canals, two on each side (fig. 1, a >), running along the body at or near
the margins of the segments, and connected toge-
ther by transverse branches; these anastomose
with one another freely in the head, those of the
opposite sides being generally connected by an
arched canal; whilst at the opposite extremity
they all terminate in a single contractile sac opening
externally. Besides these trunks (of which the
two larger, a, have been considered as a double
alimentary canal), there is a superficial system
of vessels more minutely distributed, which has
been regarded as sanguiferous ; but these may be
traced into connection with the preceding, and
their parietes are furnished with vibratile cilia,
which keep up a movement of their contents.
There is, then, no true sanguiferous system in
the Cestoid Worms, any more than there is an
alimentary canal; both being replaced by the di-
rect absorption of the nutritious juices from with-
out, in a state ready for assimilation. Yet it is
probable that, as in the cases last cited, the
‘ water-vascular’ system contains some other fluid
than pure water; and it may even serve, as Pro-
fessor Van Beneden has suggested, for a urinary
apparatus. The fluid contents of these vessels, Sexpen biel cer SOEs
whatever their nature may be, are kept in motion loaeadinal trunks; ¢,
partly by ciliary action in theirinterior, and partly ovary; 4, genital orifice.
by the contractility of their walls; the former method seems to prevail in
the smaller trunks, the latter in the large—In the 7rematode Worms, we
find a regular gradation from what is unquestionably a ‘ water-vascular,
system homologous with that of the Cestoidea, to an apparatus which
nearly approaches the reputed sanguiferous system of the Annelida, One
of its most interesting forms is that presented by the Distoma tereticolle ;
in which we find an elongated contractile canal, terminating posteriorly in
an external orifice, giving off two contractile trunks, which pass along the
two sides of the body without any change of dimension, and unite in an
arch above the mouth. The fluid of these vessels is colourless, and
contains some minute corpuscles. But besides these, there are a consider-
able number of smaller trunks, giving-off branches that form a net-work
resembling that shown at fig. 2; these trunks, however, have been dis-
tinctly found by M. Van Beneden to discharge themselves into the two
principal lateral canals, so that they must be considered as forming one
system with them, although the fluid which they contain is coloured.
This system of vessels, therefore, although usually described as sanguiferous,
cannot be properly regarded in that light; and it is obvious, that even
when (as happens in the Echinorhynct, which are closely allied to the 'T're-
matoda) there are no pale, ciliated, non-contractile aquiferous vessels, ter-

Fig. 1.

218 DR. CARPENTER, ON COMPARATIVE PHYSIOLOGY.

minating in an external orifice, but only red, non-ciliated, contractile
vessels, which cannot be traced into connection with the exterior, we must
abstain from regarding the latter as a true ‘sanguiferous’ system, since
they are obviously but an offset (so to speak) from the ‘aquiferous,’
Fig. 2. specially developed in this particular
group of animals.—The nature of the
vascular system in the Nematoid worms
has not yet been made out but there
appears strong ground for the belief that
in this order also, what has been usually
regarded as a sanguiferous system really
belongs to the ‘aquiferous’ type.

An arrangement of a different kind,
but one that seems referrible to the
‘ water-vascular’ system of inferior Ar-
ticulata, is found in the Leech and Earth-
worm, which, with their allies, constitute
the Monecious group of Annelids. In
the medicinal Leech, there is found on
either side of the posterior part of the
body a series of seventeen pairs of sacculi,
lying between the digestive ceca, and
opening by narrow external orifices; al-
though these were long ago considered
as respiratory organs, yet they have been
of late more generally regarded as organs
of secretion, their homological character,
however, as a ‘ water-vascular’ system,
appears to be demonstrated by the exist-
tence of intermediate forms, which con-
nect it with the aquiferous system of
Entozoa. Thus in the Branchiobdella
there are but two pairs of external ori-
fices, one at the anterior and the other at
the posterior extremity of the middle
third of the body; each of these leads
Anatomy of Fasciola’ hepaticum (Dis- to a trunk, which, after dilating into an

toma hepaticum), enlarged, showing ampulla, gives off several tortuous canals,

SCS EaR Ge wale eae Gethe network the lining of which is ciliated. In the

connected with a median trunk. a, the Marthworm, again, there is found in each

mouth. segment, and on either side of the diges-
tive tube, an enteroid vessel which returns upon itself, and which is lined
with cilia; and in other Lumbricide, these vessels have cecal terminations
in the general cavity of the body, furnished, like the water-vessels of Ro-
tifera, with long cilia.—Nothing similar to this has been found among the
branchiferous Annelida; and it would seem as if the water-vascular system
were superseded in them by the apparatus provided for aquatic respiration,
which will be hereafter described.—The close resemblance which seems to
exist between the multiple sacculi of the Leech, and the air-sacs of the
lower Myriapoda, strengthens the reasons already advanced for regarding
the ‘ water-vascular’ system as the real homologue of the tracheal system
of Myriapods and Insects. And if the suggestion already thrown out,
respecting the real nature of the supposed sanguiferous system of Annelida,
should prove well-founded, this also would find its parallel in the closed
tracheal apparatus of certain Insect-larve, which is connected, like it, with
a branchial apparatus ; the difference between the two being that the latter

Pg)

DR. SCHACHT, ON THE MICROSCOPE. 219

contains and distributes air, whilst the former is filled with an aeriferous
fluid, which can scarcely be called blood, the distribution of nutritive ma-
terials being accomplished in both cases by the fluid of the ‘ general cavity
of the body.’

In his account of the sexuality of the Cryptogamia, Dr.
Carpenter has embodied the most recent researches on this
highly-interesting subject. Every lover of natural history,
every student of biology, should be possessed of this new
volume by Dr. Carpenter.

‘THE MIcRoscopE AND ITS APPLICATION TO VEGETABLE ANATOMY AND
Puysrotogy. By Dr. Hermann Scuacut. Edited by FREDERICK
Currey, M.A. Second Edition. Highley. London.

Tue fact of this book having reached a second edition justifies
the good opinion we have expressed of it on two previous
occasions. Mr. Currey has taken the opportunity of adding
some new matter, which has very considerably improved this
edition. Four chapters have been added at the beginning of
the book ; the first of which relates to some elementary prin-
ciples of optics essential to a proper comprehension of the
microscope ; the second contains a description of different
kinds of English microscopes, including as far as is necessary
the details of their different parts; the third contains an
account of the accessory apparatus and chemical reagents
necessary for microscopical investigations in botany ; and the
fourth relates to the preservation of specimens. Besides these
chapters by the editor, Dr. Schacht has furnished a quantity
of new matter in manuscript, being the result of his investi-
gations since the last German edition of his work was pub-
lished in 1852.

The whole of the new matter of this volume will be found
interesting to the vegetable microscopist 5 and we select as
examples of the ane of the added matter, one extract on in-
struments and another on microscopic structure.

Disseciing Micrescope.—There are many different sorts of dissecting
microscopes, which vary according to the fancy of the makers ; but as the
principle of all must be the same, it will be sufficient to refer to the
accompanying fig. 15, which represents one of the best construction by
Mr. Ross. ‘The principal points to be attended to in selecting a dissect-
ing microscope are to see that the stage is of sufficient size and strength,
and that the arrangements for holding the lenses and moving them
in different directions, are convenient. In the instrument in fig. 15,
the arm at the top which carries the lens-holder has a forward motion by

220 DR. SCHACHT, ON THE MICROSCOPE.

rack and pinion, and a traversing motion on a pivot, by which means
the lens can be carried in any direction over the stage. The adjustment
of the focus is effected by the large milled head at the side. This instru-
ment is usually furnished with lenses of 1 inch, 4 inch, ¢ inch, and 1-10th
inch focal lengths, and sometimes with a Wollaston’s doublet. The doub-
let may well be dispensed with, if the observer is possessed of a compound
achromatic microscope. In carrying on delicate dissections with this
microscope, it is advisable to make use of the arm-rests, which will be
described hereafter in the chapter on accessory instruments. Mr. Ross’s
1 inch achromatic object-glass may be used in dissecting with this instru-
ment, and will be found most agreeable.

g.
Fig. 16. folded up with an Indian-rubber band
round it, in a manner which admits of
its being carried in the pocket. The
two wedge-shaped pieces of wood under-
neath unfold and form the legs (see figs.
17 and 18). Fig. 17 shows the internal
arrangement and the manner in which
the mirror, lenses, and lens-holder are
packed away. ‘The straight, flat bar,
on the right in fig. 17, serves to keep
the legs from closing together (see fig.
18), and also as a support for the mirror,
which slides into a piece of brass tubing attached to the flat bar. The
circular hole at the lower end of fig. 17 is another piece of brass tubing,
into which the lens-holder slides. ‘The instrument is furnished with three
lenses, and is to be had at a moderate price.

DR. SCHACHT, ON THE MICROSCOPE. 221:

Amongst the new material in this edition are three chapters
on the embryogeny of the Conifers, taken from Dr. Schacht’s
recent work, entitled ‘“ Beitriige zur Anatomie und Physiologie
der Gewiaichse.” From these chapters we extract the follow-
ing remarks on the pollen of Coniferze :—

Fig. 109 represents a young pollen-grain of Abies pectinata seen in
water, and fig. 110 a somewhat older pollen-grain, also seen in water,
where (a) is the place of the thin spot in the cuticle.

Fig. 111 represents a mother-cell of Abies pectinata with four young
pollen-grains. At the beginning of May the pollen-grains of Picea vul-
garis, if placed in water upon the stage of the microscope, frequently

222 DR. SCHACHT, ON THE MICROSCOPE.

ie i

QUEKETT?T’S TRAVELLING, DISSECTING, AND COMPOUND ACHROMATIC MICROSCOPE.

DR. SCHACHT, ON THE MICROSCOPE. 223

swell up and escape from the mother-cell; when this takes place, cells
called special mother-cells (which exist also in certain other plants, as, for
instance, Lavetera) are found to be present.

Fig. 109. Fig. 111.

Figs 112 and 113 represent mother-cells of Picea vulgaris, which have
become quadrilolucar by the formation of special mother-cells ; the young
pollen-grains having been swollen by water

have escaped from the mother-cells. These Fig. 112. Fig. 113.
special mother-cells, which were first observed fm Se

by Nageli, are nothing more than a primary HOW a Van
layer of cellulose secreted by the primordial heer, AW So
utricle of the pollen-cell, the pollen-cell itself ~/7-( | Ff \
hatin ‘one ABs danas: ae ea Ss \ A Se) Noe
having originated by division of the primordia Ay 1g VY

utricle. This layer of cellulose, like the mother-
cell, is afterwards either absorbed by the pollen-grains themselves, or appro-
priated in some other way to the perfecting of them. When the four young
pollen-cells of Picea escape from their mother-cells, the latter appear, to a
certain extent, to be divided by the special mother-cells into four partitions.
(See fig. 113.) The young pollen-grain is then generally no longer round ;
the two lateral excrescences, which at a subsequent period characterize
the pollen-grain of Picea, Abies, and Larix, are already more or less per-
ceptible.

Fig. 114. Fig. 115.

Figs. 114 and 115 represent young pollen-grains at this period, showing
the commencement of the formation of the two lateral excrescences. Fig.
116 shows a young pollen-grain of Picea vulgaris, somewhat further de-
veloped, seen under water; (x) is the place of egress of the pollen-tube.
A laige nucleus, surrounded by granular matter, lies apparently free in
the middle of each pollen-grain. From this time the lateral protuberances
continue to increase in size, the cuticle, 7. e. the outer membrane of the
pollen-erain, which does not consist of cellulose, becomes stronger and
stronger, and delicate markings, streaks, and lines appear upon it, especially
upon the protuberances.

Figs. 117 and 118 represent respectively ripe pollen-grains of Abies
pectinata and Picea vulgaris which have been soaked for half an hour in
oil of lemons ; in each figure («) is the terminal cell of the cellular body ;
(b) and (c) the pedicel-cells ; in both (c) has the appearance of a fissure, as
is the case in Larix; (a) is the place of egress for the pollen-tube. The
processes going on in the interior of the pollen-grain are at this time con-
cealed, more or less, by the granular contents ; nevertheless, I believe that
in Abies I have seen the formation of a cell-membrane, that is the origin
of a cell, around the central nucleus. When the anther of the above-

224 DR. SCHACHT, ON THE MICROSCOPE.

mentioned Conifers opens, which takes place about the end of May or the
beginning of June, every perfect pollen-grain of Larix Europea, Abies

Fig. 117.

pectinata, Picea vulgaris, and Pinus sylvestris, exhibits the cellular body
mentioned by Meyer ; there may also be seen the fissure between the outer
and the inner membrane, 7. e., between the pollen-cell and the cuticle;
the latter seems to consist of two layers, on which account Meyer speaks of
three pollen-membranes. There is also to be seen above this fissure the small
pedice!-cell, and over this again a larger cell, which encloses a very mani-
fest large nucleus. Fig. 119 represents a ripe pollen-
grain of Larix Europa seen in water; (a) is the
terminal cell of the cellular body ; (0) the larger
pedicel-cell ; (c) and (d) the smaller pedicel-cells,
having the appearance of fissures in the membrane
of the pollen-grain. In Larix the cellular body seems
frequently to be composed of four cells instead of
three. (See figs. 117 and 118.) The above-men-
tioned cellular body lies opposite to either side of
the arcuate space which is found between the two
lateral excrescences, and out of which at a later
period the pollen-tube emerges. At this place there
is to be found in the cuticle of Abies pectinata an
attenuated spot, which is rendered manifest in fa-
vourable positions of the pollen-grain by the use of
sulphuric acid; the same kind of spot probably exists in Picea vulgaris
and Pinus sylvestris, and it may be seen also in the cuticle of the Larch,
in which plant also the cellular body is situated opposite to this place of
egress of the pollen-tube. According to Geleznoff, both the outer mem-
Fig. 120. branes, and therefore the cuticle, are com-
pletely stripped off. Fig. 120 represents a
ripe pollen-grain of Larix Europea under
concentrated sulphuric acid. The contents
of it, as well as the true pollen-cell, have dis-
appeared ; some oily drops (y) are to be seen
in the middle of the cuticle (ct), which is un-
injured, but which has become rose-coloured,
and now exhibits two layers; (#) is the thin
spot in the cuticle intended for the egress of
the pollen-tube. The above-mentioned cel-
lular body may be seen most clearly and
beautifully in the pollen of the Larch, which
is round or nearly so, and in which, as is well
known, the two lateral excrescences are wanting ; but nevertheless I have
derived more information from the study of the pollen-grain of Abies
pectinata, Picea vulgaris, and Pinus sylvestris, for which it is necessary to
make use of acids and volatile oils.

DR. SCHACHT, ON THE MICROSCOPE. 225

By means of the continued action of oil of lemons or oil of turpentine,
the contents of the above-mentioned pollen-grains are rendered so trans-
parent that the construction of both the small pedicel-cell, and of the
larger terminal cell, as well as their attachment to the wall of the pollen-
cell, may be clearly seen. (See figs. 117 and 118.) This mode of observa-
tion, however, affords no information with regard to the fissure underneath
the pedicel-cell. If, however, one or two drops of common sulphuric acid
be applied to the pollen when quite fresh, and a thin glass cover be placed
over it, the immediate appearance of the pollen-cell may be observed at
the spot destined for the egress of the pollen-tube ; it swells and protrudes
itself more or less rapidly, and in a more or less perfect condition, through
the cuticle, and lies exposed before the eyes of the observer.

Fig. 121 represents a ripe pollen-grain of Picea vulgaris under nitric
acid, at the moment when the true pollen-cell (vy) emerges at (a): (ct) is
the cuticle showing two layers. Fig. 122 repre-
sents a similar pollen-grain under concentrated
sulphuric acid; the pollen-cell and its contents
have disappeared, leaving only some drops, pro-
bably of oil, behind in the cuticle. Figs. 123
and 124 represent the pollen-cell of two ripe
pollen-grains forced out of their cuticle by the
operation of nitric acid ; (a), (6), and (¢) are the
cells of the cellular body.

The empty cuticle now exhibits its markings
still more beautifully, It is now seen that, as
well in Abies pectinata as in Picea vulgaris and
Pinus sylvestris, the cuticle is very strongly developed at the two excres-
cences, and still more so between them, opposite to the place of egress of

Fig. 122. Fig. 123. Fig. 124.

the pollen-tube, at the point of attachment of the cellular body. At
the places where the cuticle is thus strongly developed, two layers may
frequently be clearly seen. The fissure between the pollen-cell and the
cuticle has now disappeared ; but three cells (and not two only, as in the
earlier stages) are always to be seen in the emergent pollen-cell, and these
three cells form the cellular body in its interior, (See a, b, and ¢, figs.
118, 128, and 124.) The lowest of these cells (c) is generally the smallest,
and becomes united in its growth to the wall of the pollen-cell ; which fact
is clearly seen by pushing the covering-glass backwards and forwards : it
was this cell which at an earlier period formed the apparent fissure between
the cuticle and the pollen-cell. The contiguous cell (6), which is some-
what larger, and which has been hitherto called the pedicel-cell, supports a
third cell, viz., the terminal cell of the cellular body (a). I have never
seen more than three cells in Abies pectinata, Picea vulgaris, and Pinus
sylvestris ; but I have never failed to see any one of these three cells in
the perfect pollen-grain.

Although I have not been able to trace the development of the cellular

VOLS It. Q

226 DR. SCHACHT, ON THE MICROSCOPE.

body, it may perhaps be assumed that its three cells originate from the
one cell which I have observed in the pollen-grain of Abies pectinata, and
probably by repeated divisions of the primordial utricle.. The two pedicel-
cells, when once formed, do not seem to increase in size, but the terminal-
cell grows visibly : in Pinus sylvestris I have met with instances in which
the latter cell has completely displaced the granular contents of the pollen-
cell, and become distended to such a size as to fill up completely the hollow
of the latter. The true pollen-cell appeared about this time to be much
decayed, and of a gelatinous consistency ; at the apex it was completely
absorbed. I cannot, therefore, at present subscribe to Geleznoff’s opinion,
that the pollen-tube is formed of two membranes.

Fig. 125. Fig. 126.

Fig. 125 represents a ripe pollen-grain of Pinus sylvestris viewed dry :
at («) the place of egress for the pollen-tube, it is folded together. Figs.
126 and 127 represent similar pollen-grains after long soaking in oil of
lemons : («), (2), and (c), are the cells of the cellular body, which has
already displaced the contents of the pollen-cell ; the latter is gelatinous
and distended ; (a) is the place of egress for the pollen-tube.

Figs. 128 and 129 represent the pollen-cells of two ripe pollen-grains of
Pinus sylvestris forced out of the cuticle by nitric acid ; (a), (0), and (c),
are the cells of the cellular body ; (y)
is the swollen wall of the pollen-cell.

I have observed the terminal cell of
Pinus sylvestris, which at a latter
period makes its appearance as a pol-
len-tube, to be in some cases filled
with granular matter, corresponding
- ie chemically to the earlier contents of
a the pollen-cell ; the two pedicel-cells

then appeared to be in a dead or dying
state. In Picea vulgaris, Abies pectinata, and Larix Europea, I have not
been so fortunate as to be able to trace fully the subsequent development
of this terminal cell into the pollen-tube. From the results of prior observ-
ations, it seems to me to be not improbable that in other Conifera: besides
the Larch, the cuticle is completely stripped off by the tubular prolongation
of the pollen-cell. In the Larch this fact has already been observed by
Geleznoff.

In the Autumn of 1853, Encephalartos Altensteini produced two male
blossoms at Hamburgh. I examined the pollen whilst fresh, but did not
discover the above-mentioned cellular body.» The pollen of the Cycadex
is round, and is, like that of the Conifere, furnished with only one place
of egress for the pollen-tube. The pollen of Encephalartos, when dry, is
folded. In that which I examined, I did not meet with the granular
contents which in the Coniferee are coloured yellow by iodine, and which
are made to burst, or become transformed into oil-drops, on the application
of sulphuric acid, This pollen seems to me, therefore, to be abnormal,
and, consequently, I do not attribute any importance to the circumstance
of the non-existence of the cellular body. It remains, therefore, to be
ascertained by further examinations of the pollen of the Coniferee and

Fig. 128.

DR. THOMPSON, ON PULMONARY CONSUMPTION. 227

Cycadex, whether the above-mentioned cellular body in the interior of the
pollen is common to all the plants of these families; and whether the
terminal cell of this body is intended in all cases to serve the same pur-
poses as in Pinus sylvestris. If it be so, a new and important characteristic
of these families will have been obtained. The examination of the pollen
should, however, be made only whilst it is fresh; after it has become
dry, the fissure to which I have referred may still be seen, but not the
cellular body. Geleznofi’s careful observations on the impregnation of the
Larch deserve to be carefully repeated.

If, as may confidently be expected, the appearances which have been
here described are found to occur in all the Conifer and Cycadex, the
reproductive organs and the formation of tne embryo of these plants will
differ from. those of all other phanerogams in the three following essential
particulars,

1. The Conifers and Cycadezw have naked ovules, that is to say, their
ovules originate in an open fruit-scale, whilst in all other (phanerogamous)
plants they make their appearance in the interior of a special organ, that
is in the hollow of the ovary.

2. The embryo-sac of the Conifers and Cycadex produces corpuscula,
which are large cells of the albumen, varying in number, and situated at
the apex of the embryo-sac, into which the pollen-tube enters, in order
that after having extended itself within the corpusculwm, it may form the
first cells of the embryo. In all other plants the corpuscula are wanting,
the pollen-tube simply enters into the embryo-sac, and forms therein the
first cells of the embryo.

3. The pollen-tube of the Conifer: and Cycadez is not (as is the case
in other phanerogams) a prolongation of the inner true pollen-cell, but an
extension of the terminal cell of a small body consisting of several cells,
which body originates in the interior of the pollen-cell, the contents of
which it appropriates to the purposes of its own development.

This work is now more than ever one that we can recom-
mend to the botanical student, as an introduction to the use
of the microscope.

LerrsomMiaAN LECTURES ON PULMONARY ConsuMPTION. By THEOPHILUS
Thompson, M.D., F.R.S. London. Highley.

Tuts work consists of three lectures devoted to the subject of
pulmonary consumption and its treatment. In the first lec-
ture there are some very good remarks on the microscopic
appearances afforded durmg the progress of tuberculous
disease of the lungs. It has oftentimes been denied that the
microscope is of any value in the diagnosis of tubercle ; and
on this subject we subjoin the remarks of Dr. Thompson,
whose opinion no one will doubt is that of a thoroughly
practical man :—
As respects the progress of consumption, the principal appearances of
the expectoration may be described under three divisions :-—
1. Frothy ; characterising irritation, which, however, may be produced
by various causes, besides the presence of tubercular deposit in the

cells.
Q 2

228 DR. THOMPSON, ON PULMONARY CONSUMPTION,

2. Gelatinous. This varievy is transparent, resembling a drop of isin-
glass, not stringy. It is indicative of a chronic form of irritation,
unlike that from bronchitis or pneumonia, and is usually tubercular.

3. The purulent, of which there are three marked varieties :—

(a) Simple purulent.

(b) Flocculent ; characteristic of secretion from a vomica, modified
by absorption of the thinner constituents ; very rarely occurring
from any other cause.

(c) Non-coherent. This is thick, scanty, rather firmer than common
pus ; sometimes brought up without cough ; often accompanied
with slight hemoptysis. It indicates a chronic form of tuber-
cular affection, in which the diseased action is checked.

Can we, by the aid of the microscope, obtain more definite and positive
information regarding these different kinds of expectoration? Micro-
scopical observers have hitherto given us little encouragement in this
attempt. Rainey concludes his paper on the minute structure of the lungs
with the remark, that the expectoration in the phthisical ‘‘ most probably
is not to be distinguished from that in ordinary bronchitis.” He adds,
“Tt will be only during the breaking up of a tubercle that matter truly
tuberculous will be expectorated ; and this, I believe, can be recognised
with certainty by no other character than its containing fragments of the
membrane of the air-cells.” Dr. William Addison, in an interesting
work,* published only five years since, observed— Great attention used
formerly to be paid to the expectoration, with a view to determine whether
it was pus and came from a cavity in the lung, or whether it was only
mueus from the air-tubes. More recently it has been supposed that a
microscopical examination would determine the point. But it is now
known that the inquiry is useless, mucus and pus being only varieties of
the excretion natural to all mucous or granulation fabrics.” Only last
year I published a discouraging opiniont as respects the prospect of de-
tiving any practical advantage from this application of the microscope.
Since that time, however, I have been induced to change that opinion, and
I now hope to show that, with careful attention, the microscope will afford
definite and conclusive information regarding the disease in its progress,
and open views of peculiar interest respecting its origin.

Frothy expectoration contains stringy mucus and the outer layer of
epithelium, cilia being often observable. A gentleman whom I visited a
few weeks since with Dr. Crosse was affected with obstinate cough. There
was some hereditary tendency to consumption ; his aspect was rather un-~
promising, and there was dull percussion in the right subscapular region.
It was doubtful whether this dull percussion depended on tubereular con-
solidation; but the absence of any tubercular element in the purely
bronchial frothy sputum, when microscopically examined, encouraged us
to give a favourable prognosis, which has happily been confirmed by the
successful issue of the case.

The second variety—namely, the gelatinous, is transparent, not stringy,
and resists pressure between the glasses of the microscope. It contains
granules, molecules, not aggregated, cells partly devoid of granules, and
oil globules. (See fig. 3.)

A more advanced stage is seen in fig. 4.

Of the third kind—namely, the purulent—the flocculent is so charac-
teristic of phthisis, that from its external appearances alone we may almost

* On Healthy and Diseased Structure, p. 159.
+ Clinical Lectures on Pulmonary Consumption, p, 49.

DR. THOMPSON, ON PULMONARY CONSUMPTION. 229

od

venture on a diagnosis. Under the microscope the correctness of this
opinion is usually established by the appearance, mixed with pus corpus-

cles, of the unmistakable shrivelled cells, granules, molecules, and oil
globules (see fig. 5), not unfrequently also of the curled elastic tissue
surrounding the pulmonary vesicles.

oO

fy
te
0
|
°
°c

20
ee
7
5)
ry i
apo
47 O JO)
ea
i 1/2
io

a abe ;
=a

Every one must feel, after reading this passage, that how-
ever imperfect the assistance yet obtained by the practical
physician from the use of the microscope, that in the course
of a short time it will form one of his important means of
diagnosis,

* Fig. 6 represents the same after the application of acetic acid.

( 230 )

NOTES AND CORRESPONDENCE.

Feet and Wings of Insects.—In confirmation of the opinion
of Mr. Hepworth and other naturalists, that the use of the
cushions beset with hairs terminating in glands secreting a
glutinous substance, is to attach the foot to what it walks on
by means of such secretion, and not by suction, I would
suggest that the hooks on the feet of flies are intended not to
attach the fly to anything, but to be used as fulcrums (fulcra,
Mr. Editor, “ if you think it better English,” as Lord Plunket
said when corrected for using the word memorandums), or
props which the fly can push against when it wishes to detach
the cushions. Without these hook-shaped props, the fly,
when once stuck fast, must remain so.

Some Hymenoptera, Messrs. Kirby and Spence state, have
hooklets on their wings. ‘These are used to attach one wing
to the adjoining wing during the insect’s flight. My observa-
tion leads me to think that these hooks are a distinguishing
characteristic of all Hymenoptera; but I throw out the sugges-
tion for the investigation of naturalists. The hooks vary
very much in number. In some minute Hymenoptera, we find
but three, while on the wasp I think there are twenty-four,
and on the hornet, twenty-eight. They are invariably on the
smaller wing, and the margin of the other is folded back, and
thickened at the edge to give the hooks a firm hold of it.

So far as my experience goes, these hooks are confined to
the Hymenoptera, with but one exception—the aphis. Every
aphis possesses one or more hooks on the smaller wing for the
same purpose of attachment; but while in the Hymenoptera,
they are arranged separately along the margin of the wing,
in the aphis, on the other hand, the hooks, however numerous,
spring from one point, or at least are placed as closely as
possible together. ‘The number of hooks differs, in the different
varieties of aphis that I have examined, from one to seven.

An aphis found on the Box and on the Hawthorn appeared
at first to have none, but after a careful inspection, the hook
was found of a different shape from what is usual, inserted in
the wing not quite at the edge, and standing out perpendicular
to the plane of the wing. The Box- and the Hawthorn-aphis
have this further peculiarity, that to compensate for the absence
of hooks in their usual position, they have a row of hooks
near the insertion of the wing in the insect’s body, and the
larger wing has a corresponding fold at the same place to re-
ceive them.—Joun TYRRELL, Newcourt.

MEMORANDA. yl

Hooks on the Sycamore-aphis, magnified about 800 diameters.

Fig, 2.

a, Wing of Sycamore-aphis ; b, c, Wings of Box-aphis.
Fig. 3.

Wings of Sycamore-aphis, held together by the hooks.

232 MEMORANDA.

The Markings of the Pleurosigma, &e.—In the ‘ Memoranda’
of the last number of your interesting Journal, a short notice
was inserted on the “curious effect of moisture on the mark-
ings of the Pleurosigma,’ in which I spoke of the subject of
the markings as one, “still, 1 presume, involved in obscurity.”
When this was written, I had not seen the following quotation
from the ‘ Philosophical Magazine’ for January, 1855, which
occurs in an abstract of a paper read before the Royal Society,
«On the Structure of certain Microscopic Test-objects, and
their Action on the Transmitted Rays of Light.” By Charles
Brooke, M.A., F.R.S. The passage is as follows: “ The
‘dots’ have by some been supposed to be depressions ; this
however is clearly not the case, as fracture is invariably ob-
served to take place between the rows of dots, and not through
them, as would naturally occur if the dots were depressions,
and consequently the substance thinner there than elsewhere.”
Now when writing the former notice, and quoting a passage
from the introduction to the ‘ Micrographic Dictionary’ now
publishing, in which a diametrically-opposite view is main-
tained, I was not prepared to find such eminent observers as
the nee of the above-mentioned work, and Mr. Brooke,
taking such wholly irreconcilable views, and each, moreover,
basing his view upon wholly irreconcilable statements of the
same fact, namely, the course of the line of fracture of the
shell. The observation of this fact is, I should think, simple
and easy to an experienced observer who possesses our most
powerful objectives, and I am not without hope that the juxta-
position of two such contradictory statements made by such
experienced observers, will induce some one qualified by ex-
perience, and possessed of sufficient instrumental means, to
bring forward such undeniable evidence of the truth of either
one statement or the other, as may set at rest the question of
the course of the line of fracture ; which will be a step, and an
important step, towards ascertaining the precise nature of the
markings. I may add, that in those species of the genus
Pleurosigma, which have the “ striz transverse and longitu-
dinal,” such as the P. Hippocampus, 1 have observed that
when moisture has insinuated itself between the glasses in
which they are mounted, the boundary line between dryness
and moisture has always a tendency to arrange itself in lines,
either transversely across or along the shell, which in this case
are manifestly parallel to the two directions of least distance
of the dots. Granting that the Diatomacee belong to the
Vegetable Kingdom, the nature of these dots, may, I think,
be added to the list of questiones vexate in vegetable anatomy
adduced by Mr. F. Currey, in his paper in the ninth number
of this Journal, “* On the Spiral Threads of the Genus Trichia,”

MEMORANDA. 233

in which he says, “ the opinions of observers not only differ
from one another, but are so utterly and diametrically at
variance, that if one side be right, the other must be altogether
wrong.” —G. Hunt, Handsworth, Birmingham.

Definition of Delicate Test Objects.— With Powell and Lea-
land’s 1-4th objective, and the A eye-piece, the magnifying
power being 200 diameters, using also their improved achro-
matic condenser, No. 8 aperture, without the stop for the
central rays, I have clearly defined the double set of lines at
the same time of Navicula cuspidata and Pleurosiqgma Fasciola,
also the fine markings of Navicula obscura and P. delicatula,
and the still more difficult ones of Nitzschia sigmoidea.

With the 1-8th objective and the same eye-piece, the mag-
nifying power being 400 diameters, I have brought out the
dots of Pleurosigma obscura and P. delicatula as plain as in
the P. angulata, and also the very delicate markings of the
Amician test, Grammatophora subtilissima, and Navicula
rhomboides and (Pleurosigma?) macrum. In fact the Diato-
macee generally are brought out in a most distinct manner,

The angular aperture of the 1-4th objective is 95°, of the
1-8th, 125°, and of the condenser, 105°.

The microscope is placed at the polarizing angle 56° 45’,
The illumination is that of the small camphine lamp, the base
of the flame being 72 inches from the level of the table, the
flat side of the mirror being uppermost, and nearly: horizontal,
and 2% inches below the base of the flame, and at a distance
from it of about 12 inches. The achromatic condenser is
racked up very near to the object: with this preliminary
arrangement, by a slight movement of the mirror and con-
denser, a small triangle of brilliant light is obtained at the
base of the field; above the bright light is a deep yellow,
filling the space of more than half the remainder of the field,
the remaining portion at the top being very dark ; on the yellow
portion of the field the object is so arranged, that the intense
light from the bright angle may be thrown upon it, and then
the delicate markings immediately appear, This diagram
may explain it more “clearly.

A, the angle of bright light. B, yellow
ground, C, ome ground.

The objects are placed in either position
as placed in the diagram.

The markings of (Pleurosigma ?) macrum,
NN. rhomboides, the Amician test, and Gram-
matophora, are made still more distinct by
placing stop 1 as marked in the portion A of the diagram.

234 MEMORANDA.

Cheap Microscopes—IT he President of the Microscopical
Society in his late address drew attention to the general im-
pression, that in order to make good observations it was
necessary to have a high-priced microscope. He denied this,
and stated his conviction that all the arrangements necessary
for accurate investigation might be obtained at a very much
lower price, than is given for the very perfect and beautiful
apparatus of our first makers. The drawback on purchasing
cheap microscopes is the want of knowledge of the properties
of good glasses on the part of beginners. As the use of the
microscope is now becoming a matter of educational import-
ance, and as in order that it may be used by all, it must be sold
at a price to be attained by all and at the same time a good
instrument insured, the Society of Arts has offered two prizes
for the best microscopes at stated prices. We have much
pleasure in drawing attention to the following announcement
of this Society. ‘The Council has determined to offer special
prizes—

1. For a School Microscope, to be sold to the public at a
price not exceeding 10s. 6d.—Prize— The Society’s Medal.

To be a simple microscope, furnished with powers as low
as those of a pocket-magnifier, for the purpose of observing
flowers, insects, &c., without dissection. The lenses should
range from two inches to 1-8th of an inch; the focal adjust-
ment to be by rack-work, extending sufficiently above the
stage to allow a thick object to be brought under the lowest
power. It should be furnished with plyers, a concave mirror,
and an illuminating lens, also a live box, or, instead of it, two
or three glass cells of different depths, a few slips of common
glass, and a few pieces of thin glass for covers.

Makers are requested to state at what additional price
they will undertake to supply a doublet of 1-16th or 1-20th
of an inch, applicable to any instrument as above described.

2. For a Teacher's or Student’s Microscope, to be sold to
the public at a price not exceeding 3/. 3s.—Prize— The

Society’s Medal.

To be a compound Achromatic Microscope, with two eye-
pieces and two object-glasses, one magnifying 120 diameters
with the lower eye-piece, the other magnifying 25 diameters
with the lower eye-piece. It should be furnished with a dia-
phragm, having various-sized openings, mirror, side illumi-
nator, live box, forceps stage and case.

In the event of the medal being awarded, the Council is
prepared to take 100 of the smaller and 50 of the larger micro-
scopes, at the trade discount.

MEMORANDA. 235

The instruments for which the medals shall have been
awarded will be retained by the Society as standards ; and the
successful competitors must enter into a guarantee to supply
their microscopes at the foregoing prices, and of equal quality
with those retained, and to change them if not found satis-
factory.

The Council, in all cases, expressly reserves the power of
withholding the premium or medal altogether, should the
essays and articles sent in competition not be considered
worthy of reward.

The essays and articles intended for competition must be
delivered, addressed to the Secretary, at the Society’s house,
free of expense, on or before the Ist of May, 1855.

Cilia in Diatomacex.— During my examinations, near the end
of the last summer, of the ciliary motion in the Desmidiee, I
frequently noticed in many of the more commonly met with
forms of the Diatomacee a similar arrangement of cilia. I
have attentively watched Diatomacee moving slowly and
steadily across the field of the microscope, when upon meet-
ing with any obstacle to their progress they have changed
their course, or pushed the obstruction aside, as if conscious
of an impediment. I have repeatedly satisfied myself that
their motive power is derived from cilia, arranged around
openings at either end; in some
around central openings, which
with those cilia at the ends act
as paddles or propellers. This
arrangement is indicated merely
in the very rough sketch I made
at the time, as I then antici-
pated other opportunities for
the purpose of rendering them
more perfect. Before I had
made out the cilia, I thought it very remarkable to see these
little bodies moving along, and steering their course by a
power which they were evidently able to call into action and
restrain at will, I was therefore agreeably surprised to find
this motive power due to cilia. The position assigned to the
cilia, it will be observed, differs much from the ciliary pro-
cesses found in the Desmidiex, and which is only, I believe,
a physical force acting independently of any controlling power ;
on the contrary, with the Diatomacee their cilia appear to
act in obedience to some will, for intervals of rest and motion
are most clearly to be distinguished ; and this knowledge
would naturally induce a doubt, or cause one to inquire once

236 MEMORANDA.

more, whether the Diatomacexe are properly classed in the
vegetable kingdom ?

I would take this opportunity of impressing upon the atten-
tion of those microscopists, who wish to examine for them-
selves the ciliary movements of the lower forms of life, the
necessity of using only very shallow cells for the purpose, say
of from 1-50th to 1-100th of an inch deep, and glass covers of
from 1-150th to 1-250th of an inch thick. The objective
must be 1-4th or 1-8th, with a good eye-piece; the objects
themselves should be carefully illuminated, by using for the
purpose a parabolic reflector, or a Gillett’s condenser, and the
examination be conducted during very bright weather or in
sunlight.—J. Hoee.

New Mode of Eilamination.— Your obliging insertion in the
last number of the ‘Microscopical Journal,’ of my note on
‘ Closterium,* tempts me to send you another Memorandum,
in the hope it may be found worthy of a similar corner in
your next.

Those who, like myself, do not happen to possess either a
Wenham’s or Shadbolt’s parabolic condenser, will find the
following plan an efficient substitute, perhaps even superior
to those instruments for defining certain structures.

With a steady clear lamp-light throw a strong background
illumination, according to the method of the Rey. Mr. Reade,
rendered more intense by using a bull’s-eye lens placed near,
and with its convexity toward the light, and a smaller con-
densing lens (on a separate stand), focusing the bright light
on the object beneath the stage, and at an angle beyond the
range of the angular aperture of the objective. Then let the
rays which have passed through the slide be received above
the stage, on either a side-reflector or a Lieberkuhn, placed
so as to reflect them on the object from the side opposite
to the light. A brilliant illumination on a dark or black
ground is thus produced, which displays many objects with
extreme distinctness and beauty, and, as in all background
illumination, with the great advantage of preserving their
natural form and colour.

Among those best adapted for illustration by this method,
are the coloured spicule of Gorgonia; recent and fossil
Foraminifera; partially-transparent injected preparations ;
palate of Myliobates ; hair of Indian Bat; scales of Lepisma,
of Amathusia Horsfeldii, and of many other butterflies and

* Allow me to correct a mistake of your printer, in inserting the last
paragraph but two at page 172, which was not intended for the press, but
to account for the erasure of some experiments narrated in the original MS.

MEMORANDA. 237

moths, all of which may be beautifully seen under an ordinary
l-inch lens. With a 34-inch of moderate aperture (57°), and
Lieberkuhn, the markings on several Diatomacex, as JN.
Jormosa, elongata, Hippocampus, Baltica, and Stauroneis
Phenicenteron are splendidly shown in distinct ridges; and
by using the draw-tube, a clear definition may be obtained
of P. angulatum. I have, even with the same lens, exhibited
palpable indications of the lines on an (American) Amician

test, P. gracilis.—T. G. Wrieut, M.D., Wakefield.

Auother Finder— The best description of “ Finder” for the
microscopist appears still to be an open question.

It has been made abundantly evident that a strong pre-
dilection exists in favour of the ring, or circle around the
object, although the methods of effecting it have hitherto
been most uncertain in their results, as well as both difficult
to accomplish, and disfiguring in appearance to the slide
when required for the cabinet. To produce this ring by
‘‘ machinery” had occupied my attention long before Mr.
Tyrrell’s description of a ‘ Finder” appeared in your third
number, but, on reading that, a new idea was suggested by
the rectangular scale. ‘The result has been the cross lines
near the edge of the slide, as shown in the accompanying
diagram ; but as it was soon made apparent that, in addition to
these, some definite indication of the precise spot was
absolutely necessary, the original idea was fallen back upon,
and has been put into practice with the most perfect success.

The annexed sketch is the full size of the original, attached
to a “ quarter” of Ross.

A, a brass cap, fitting upon the end
of the object-glass, which it entirely
covers up and _ protects from injury. '
The upper end is thin and slit so as to
move round easily without shaking.

B, a stem soldered to the side of the
cap, with the upper end having two
projecting sides to steady the ends of
C, e, and f, which are firmly screwed to
ri

C, an elastic arm of hammered brass,
which carries at its lower end, D, a
lever of thin brass plate, having a frag-
ment of diamond inserted in its thinner
end, and directly under the centre of
the cap A.

c and f are two springs, pressing upon the shorter end of

238 MEMORANDA.

the lever D, the longer one, f, has a hole, to allow the screw,
h, to pass without touching it. .

g, a screw, holding the two springs and the elastic arm to
the arm of the cap.

h, a milled screw, to adjust the elastic arm C, so as to
bring the diamond point away from the centre, according to
the size of the ring required.

I have one attached to a half-inch, but the quarter is by
far the most useful, as this is the power I generally employ
in searching any new material.

Before commencing the examination of a slide, the latter
should be firmly fixed to the stage, by bringing the slip to
press tightly on its edge. Having now found any particular
specimen and brought it into the centre of the field, and
having been careful to adjust the mirror in a line with the
tube, if not using a condenser, the body of the instrument
may be run up and the cap A slipped on to the end of the
object-glass, with the upright arm, B, either directly in front,
or behind, in a line with the stem. The whole may then be
moved down again till the scratching-point touches the surface
of the cover, which can easily be seen by the movement of
the lever when looking at it horizontally, and applying the
finger to the side of the screw h, the cap may be turned
round on its centre, making a neatly-turned circular scratch
on the cover, with the object perfectly central. By working
the slide upwards or downwards, and making a straight line
at the side, either up to the edge itself, or crossing a longer
line parallel with the edge, and produced by using the other
movement of the stage, any particular circle may always be
found at once, and may also be registered on the end of the
slide. After the circle has been completed, the vertical
motion of the stage will produce a line with a loop at the end,
which is, perhaps, the most ready guide to the object sought
for.

After a number of trials and various alterations, the present
arrangement is the simplest and most effective | have been
able to devise; but being only an amateur workman, it does
not contain so many “ perfections,” perhaps, as any of our
celebrated opticians may be able to add to it should it become
an article of “* manufacture ;” as, for instance, a wheel and
pinion to give the circular motion, and again, by a graduated
scale on the lever D, the size of the circle, which ranges up
to an eighth of an inch, might be determined beforehand with
the greatest nicety. Slides thus marked are by no means
conspicuous, and require to be seen by reflected light to
detect the rings. ‘Their appearance may be judged of by the

MEMORANDA. 239

accompanying duplicates, one of which being mounted dry,
that is, with the cover merely supported by its edge, will
show the delicacy and little risk there is in cracking the thin
glass. In examining a slide, it will, of course, be necessary
to focus for the upper surface of the cover first, until the
circle be found, when, on lowering the object-glass, the
specimen will be seen in the field, if the light in both cases
has been central—W. K. Brineman, Norwich.

On the Aperture of Objeci-giasses.— Having read over the re-
marks in your last number on the Aperture of Object-glasses,
by my friend Mr. Wenham and Dr. Robinson, I should wish
to offer a few remarks ; not that I shall attempt to take up the
valuable pages of your Journal by discussing the matter in
the two papers, but I should wish to call attention to a par-
ticular fact connected with a well-conducted experiment
named in my last communication, and which neither Mr.
Wenham nor Dr. Robinson have noticed. For if it be a fact
in one case that the angle of aperture of an object-glass be re-
duced when brought to bear on an object mounted in balsam,
it must be so 7n every case. The experiment which I refer to
is one which I have again tried with great caution, and with
the same result.

Let aa bea pencil of light falling upon the under-surface
of the anterior lens of a set of wide aperture, say 152°, and
let the central ray of the pencil aa make an angle of about
75° with the axis of the lens b 4; take two sliders, the one con-
taining an object mounted dry, ad the other an object mounted
in balsam, and let them be so selected that the object in both
sliders may be exactly in focus when placed under the ob-
jective, without having occasion to move the adjusting screw.
Now, when the pencil of light makes an angle so great as
above stated, a part of the field of view will not be perfectly
illuminated ; place the slide with the dry object under the
objective, ae it will be found that the fieid is still partly
illuminated as before; then remove this slide and place the
one below containing the object mounted in balsam, the field
is still invariably Haminateds in the same manner eee being
no difference in the illumination, however the rays may have

240 MEMORANDA.

been refracted before they reach the objective, either by the
glass in the first slide or by the glass and balsam combined in
the second: it being thus proved that however the rays may
have been refracted by the different media, and however we may
reason from theory upon those refractions, the actual working
aperture of the objective remains, under all conditions, exactly
the same ; for if it were reduced by any of those refractions,
not one single ray of the pencil aa could ever reach the eye of
the observer at the upper part of the microscope. Indeed, I
have tried this experiment with a set of lenses of 1-12th of an
inch focus and 152° of aperture, and on removing those from
the instrument, and placing on it another set of the same
power, but of 148° of aperture, the field was unilluminated ,
and the effect of the black ground immediately produced, at
once pointing out that if by any refraction the aperture of the
lens had been reduced only 2° on each side of the perpen-
dicular, the effect of each refraction would have been imme-
diately seen. With respect to the markings on the Diato-
macez, and the manner in which they are effected by balsam,
I think Dr. Robinson has forgotten that none of those minute
and beautiful forms are without some portion of colour; and
although balsam makes objects more transparent, and con-
sequently appears to rob them of a part of their colour, it still
leaves sufficient even in the smaller forms of the Diatomacez
to render both them and their markings perfectly visible.
Who would ever contend that the mar kings on the larger
Pinnularia are not much better seen in balsam than when the
object is mounted dry? and, as I stated in my last communi-
cation, I have two slides of the NV. rhomboides (Amician test),
the one mounted dry and the other in balsam, and [ can at all
times see the delicate markings on this object quite as well,
or even better, on the specimens in balsam than on those
which are mounted dry. To an uneducated eye the markings
on the dry objects may appear more striking, on account of
their stronger colour; but to a well-educated eye the superior
sharpness and exquisite beauty of those objects when balsam-
mounted is such as it would be vain to look for when they are
in their natural state. Again, I think it rather an unfair way
of testing the visibility of the markings, either in or out of
balsam, by the use of high eye-pieces; for at the same time
that you reduce the light by the eye-piece, you destroy the
effect of the difference of colour, and therefore, of course, when
this difference is small, as it is in balsam-mounted Diato-
mace, you might as call blot out the object altogether. To
see objects well when they are so very transparent, you want
all the light you can obtain, as the greater the light the

MEMORANDA. 241

greater will be any dissimilarity in colour of the various parts ;
but if you destroy the intensity of the light, by using a high
power eye-piece, you might as well try to see it with the low
power, and a telescopic sun-shade over it. I have a five-feet
achromatic telescope which will show the fifth star in the
trapezium of Orion very well with a power of 100; but with
higher powers you cannot see the small star, because the
telescope bas not sufficient light to show the difference in the
colour of the faint star and the nebula by which it is sur-
rounded. This equally applies to microscopic vision, par-
ticularly where the object is very transparent, and the difference
in colour between the object and the balsam comparatively
small,

With regard to the diminished aperture, as made apparent
by the methods employed by Mr, Wenham and Dr. Robinson,
when applied to balsam-mounted objects, I think it is very
easy to account for the conclusions they have been led to;
for every one conversant with optical instruments knows
that the larger the aperture in proportion to the focus, the
greater will be the aberration of the rays passing through or
from the edge of such aperture, as, in a telescope of large
aperture, one angular inch in the centre will give as much
light as eight or ten angular inches taken in the form of a
ring round the extreme edge of the glass ; no wonder then, that
in the objective of a microscope, where the diameter of the
aperture is seven and a half times that of the focus (which it
is when the aperture is 152°), the aberrations from near the
edges of the glass should be so’ great as to cause the rays not
to be visible after having passed through balsam.

I recollect that the last time [ had the pleasure of seeing
Mr. Wenham he told me he had made a 1-8th, the aperture
of which was somewhere between 170° and 180°, but on
account of the weakness of the rays at the edges, arising from
aberration, he would not undertake to say within 4° or 5° what
the exact aperture really was.

With these observations I shall conclude my remarks, being
fully persuaded that when objects are mounted in balsam that
medium has no effect in reducing the aperture of the objective,
and that no external cause, except a fluid or other medium
in actual contact with the objective, can, consistently with
the known laws of optics, produce such an effect.—J. D.
Sotutr, Hull.

On Washing and Concentrating Diatomacee. Having read in
your last Journal the excellent paper by Mr. Okeden “On a
mode of Washing and Concentrating Diatomaceous Earths,”

VOL, ITI. R

242 MEMORANDA.

and having lately used a similar process with some success, by
allowing the Diatoms to fall through a given length of water,
I beg to forward you the method I have adopted.

I first boil the deposit in strong hydrochloric acid for five
or ten minutes, then allow it to Gqubside; pour off all the
acid, and by a ‘few washings get as much of it away as pos-
sible. Then treat the deposit in the same way with strong
nitric acid, washing the deposit by repeated washings to get
rid of the remaining acid. When this is done, I then separate
the Diatoms according to their different gravities by allowing
them to pass through a column of water in the following
manner :—

I take a long glass tube about four feet long and half an
inch in bore. At the bottom of this tube is fixed a stop-cock
to enable me to let eut any of the Diatoms during any stage
of the process. Having nearly filled this tube with distilled
water, | pour in my deposit washed free from the acids. I
watch the deposit as it falls slowly and gradually down the
tube, and with a Codington lens can easily detect the larger
Diatoms as they are precipitated. In about a quarter of an
hour, many of the larger forms will have descended to the
bottom of the tube. By turning the tap at the bottom of the
tube, I let out a drop of the mixture on a slide, and examine
it with a low power (34-inch) ; and if it be tolerably clear, and
the Diatoms of one character, I then let off five or six inches
of the mixture into a test-tube, and set it aside for re-
examination after the Diatoms have subsided. In a quarter
of an hour more, I again let off into another test-tube six
or eight inches more of the mixture, and place it aside to
settle. In half an hour more [I let off into another test-tube
six or eight inches of the mixture, which will contain the finer
Diatoms by themselves, generally free from all mud and
sand. I then pass each of these washings again through
the long tube of distilled water; and by examining the
mixture during the process of its subsidence, I am enabled
to let out the heavier particles of sand or mud, and to obtain
pretty clean all those Diatoms which are alike in size, or at all
events in specific gravity. Some Diatoms take a longer time
than others in settling to the bottom of the tube, and ‘separat=
ing themselves from ex eee matter, such as the Witzschia
closterium, &c. ; but, bya little patience, and an extra washing
through the tube, these difficulties may, in a great measure,
be overcome. By this method, [ have found the Pleurosigmata,
Pinnularia, Surirella, and Synedre, very well separated, those
of a like character being found together. I have been
stimulated to send you these few remarks on the washing of

MEMORANDA. 243

Diatomacez, on account of the great difficulty I have hitherto
experienced in procuring slides free from mud, sand, and
other extraneous matters—H. Munro, M.D., M.R.C.S., &c.,
Hull.

Campylodiscus clypeus.— On September 6, I found in brackish
water, near Yarmouth, what I took to be Campylodiseus bicos-
tatus, specimens of which so named I distributed amongst
several members of the British Association, at the Liverpool
meeting. I now find it should have been named C. clypeus,
and which I understand is new to Britain—R. WicHam,
Norwich.

Cilia on the surface of Conferve.— Although I am aware that
the existence of cilia on the Oscillatorie has been inferred
from the motion of particles of matter in the water in their
neighbourhood, [ am not certain whether any observer has
distinctly seen them. It may be of interest to some of your
readers to know that by using a dark stop with the achro-
matic condenser, the whole surface of a large species of
Oscillatoria (found in brackish water) may be seen covered
with cilia moving in a circular sweeping wave round the
axis of the organism: this motion is particularly distinct
and beautiful at the sutures of the segments, where the
cilia may be seen en profile, and seem to form a distinct
fringe. At the “smaller end,” which one occasionally finds
on the longer pieces, the motion is very lively, as well as that
peculiar “ vermicular” waving which is so characteristic of the
species. The ciliary movements are only to be made out
clearly (in the specimens which I have examined) whilst they
are in a state of progression, which inclines me to suppose that
that motion at least is produced by their agency.

The object-glass used was a 1-4th, of Mr. Pillischer’s make,
with a large angle of aperture, and the shallow eye-piece.—

G. H. Krnestey, M.D., Glossop Hall, Derbyshire.

On an easy method of wiping Thin Glass Covers.— AS many of
the readers of the ‘Microscopical Journal,’ like myself, may
have found great difficulty in wiping the thin glass covers for
microscopic objects, by the ordinary method of holding them
between the thumb and finger, without occupying considerable
time and frequently breaking them ; may I venture to suggest
that the following method, which I have adopted for some time,
will, I think, be found a much easier, and at the same time
a much safer way of effecting the above object?

After having washed the covers, I take two or three out of

R 2

244 MEMORANDA.

the liquid and lay them on a piece of calico spread out on a
table or other flat surface. I then remove most of the liquid
from one of the pieces by rubbing it on the extended calico.
Having removed most of the moisture in this way, I place the
cover ona piece of buff about 10 inches long and 2 inches
wide, fastened on a flat piece of wood of the same size, and
by means of an old cambric handkerchief or bit of leather
twisted round my fore-finger I rub it towards the other end,
turning it in its course, when it will generally be found to be
quite clean and fit to be put away ready for use at any time.

With a little practice this method will be found to bea
very easy one, and attended with very little risk of breakage.
—WiuuAm Hopeson, 62, York Street, Lambeth.

Metallic impressions of Wicroscopic @bjects.— The transparency
of some microscopic objects frequently renders it a matter of
difficulty to determine satisfactorily the details of their surface
structure, or whether indicated lines, dots, or markings, are
really dependent upon exterior configuration. Many of these
objects, from their translucency, refract and reflect light, in
such various directions, that their superficial formation becomes
almost a matter of conjecture; neither is this doubt always
to be resolved by viewing them as opaque objects, for in this
case also, the same transparency prevents them from intercept-
ing and dispersing a sufficiency of light, to render the question
a conclusive one. ‘

The siliceous valves of the Diatomacee are a class of
objects peculiarly possessed of the above characteristics. It
has long been a point of dispute, whether the markings
which nearly all these objects display are invariably caused
by projections on their surfaces, or by the mechanism of
their internal structure. I have long been of the former
opinion. A careful study of the coarser varieties will
distinctly prove that the markings are raised ribs or promi-
nences on the surfaces; in some instances occupying one
side of the scale only, as seen in the Campylodiscus spiralis,
and others. ‘Though the microscope proves this fact satis-
factorily in the large species, it fails to do so in the most
difficult specimens, chiefly on account of the above-named
deceptive appearances, arising from the irregular refraction
and reflection of light. °

It occurred to me that it might be possible to obtain a
perfect cast or impression of the structure, and by viewing
this as an opaque object, the errors of refraction would be
avoided, and a discovery might be the reward of the experi-
ment. JI have succeeded in effecting this, by means of the

MEMORANDA. 245

electrotype process, which, for many reasons, is to be pre-
ferred, as it does not distort the object, and is so minutely
faithful, that even the mere trace of organic matter left by a
slight finger-mark is perfectly copied. The method that I
have adopted is this—procure a small plate of metal highly
polished (a piece of daguerreotype plate answers extremely
well), and after gently heating it, rub a piece of bees’-wax
over the surface ; while this is still melted, wipe it nearly all
off again with a piece of rag, so as to allow a very thin film
to remain. When the plate is cold, arrange the Diatomacee
or other objects, previously moistened, upon the waxed
surface, heat the plate again to at least 212°, in order to
cement the objects on to it. The wax serves a twofold
purpose—first its interposition prevents the possibility of a
chemical union of the metallic deposit with the plate; and
secondly, the object is securely held thereto by its agency.
The objects are now ready to receive a coating of copper.
If the battery is in good working order, three or four hours
will give a film sufficiently strong to bear removal ; when this
is stripped off, if the process has been properly managed, the
objects will be seen embedded in its surface. Whether they
are siliceous or organic they may be entirely dissolved out,
by boiling the cast in a test-tube, with a strong solution of
caustic potash, and afterwards washing with distilled water ;
the copper film may then be mounted in Canada balsam.

By these means I have obtained distinct impressions of the
markings of some of the more difficult Diatomacea, such as WN.
Balticum, P. Hippocampus, &c.,leaving no doubt of their promi-
nent nature. Care must be taken not to leave too much wax on
the plate, or either a clean deposit will not be obtained, or the
objects will be obscured by it. On the other hand, if too little
is left, the copper will insinuate itself underneath the structure,
and raise it from its place. Upon one occasion,| dried a section
of wood on to a metal plate by heating it. In this state it
appeared to be firmly adherent by its own resinous exudation.
On placing it in connection with the battery over night, in
the morning I found the bare section on the outside of the
metallic deposit, upon which it had left a slight, though by
no means a good impression. Even when a thin film of a
non-conducting substance intervenes, the tendency of the
deposit is to get as near as possible to the conducting plate,
and in its endeavours to do so, it will fill every cavity and
pore, however minute.

There is another method of obtaining metallic casts of minute
objects that gives some curious results, and is, therefore, worthy
of mention: it is done by stamping, or the same process in

246 MEMORANDA.

miniature as that by which the plates of Auers’ “ nature-
printing ” are formed. Take some perfectly clean and bright
tinfoil, three or four times doubled, and lay it upon a smooth
block of metal. On the upper surface of the foil place the
object; hold upon this a short steel punch with a highly-
polished face, and strike it a smart blow with a hammer. In
this way fish-scales, feathers, and sections, may be fairly
impressed in the tin. For delineation of surface this process
is not much to be depended upon; for if contiguous parts of
the object are hard and soft, or more or less elastic, it will
develop markings where they do not really exist. As an
example, when a mouse hair was copied by the electrotype,
it was shown to be nearly smooth, but when stamped into the
foil, all its characteristic pigment-cells were displayed in the
metal in a very beautiful manner. It has often been thought
that these cells are real external cavities ; which appearance is,
doubtless, a deception of refraction. The last operation also
displays some singular peculiarities in other animal hairs. I
think that it would be an improvement to make use of a
fly-press instead of the hammer and punch.—F. H. Wennam.

Note on Dr. Griffiths’ Paper on Angular Aperture.— We have
received a communication from Dr. D’Alquen, containing
“ Further Remarks on Dr. J. W. Griffiths’ Paper, on the
Angular Aperture of Object-glasses, &c.,” im which that
gentleman complains in very strong terms of the way in
which his objections are noticed by Dr. Griffiths in the
Micrographic Dictionary, Art. Diatomacee, p. 203. And in
support of his own views, he states that they had elicited
the spontaneous approval of one of the best authorities on the
subject, who had written to him to the following effect :—

‘“‘ T have, however, to congratulate you upon the plain and
matter-of-fact method by which you refuted Dr. Griffiths’
visionary theory, and which I think he will find it difficult to
answer, even if he should feel so inclined.”— Ep1tors.

ERRATA.

Page 110, line 35, for solid, read sold.
» 119, ,, 36, for Plate IX. read Plate VII.
», 124, ,, 22, for soniferous, read coniferous.

( 247)

PROCEEDINGS OF SOCIETIES.

Microscoricat Society. December 27th, 1854.
Dr. Carpenter, President, in the Chair.
A paper was read by the President, on the Development of the
Embryo of Purpura lapillus (Transactions, vol. iii., p. 16).
J. Shuter, Esq., was balloted for, and elected a Fellow.

January 24th, 1855.
N. B. Ward, Esq., in the Chair.
A paper was read from Mrs. Herbert Thomas, on Cosmarum
margriatiferum, and other Desmidez.
Dr. Herapath, of Bristol, and J. E. Smith, Esq., were balloted
for, and duly elected.

February 28th, 1855. Anniversary Meeting.
Dr. Carpenter in the Chair.

The Report of the Council was read. The President delivered
an address.

F.C. Hills, Esq., Charles L. Leaf, Esq., Dr. F. Degrave, and
R. C. Griffiths, Esq., were balloted for and elected.

The ballot for officers resulted in the re-election of Dr. Carpenter,
President ; N. B. Ward, Esq., Treasurer; and J. Quekett, Esq.,
Secretary.

The following gentlemen were added to the Council:—J. N.
Furze, Esq., H. Perigal, Esq., Jun., Rev. J. B. Reade, and J. B.
Simonds, Esq.

Roya Soctety.

“ Micro-chemical Researches on the Digestion of Starch and Amy-
laceous Foods.” By Purwire Burnarp Ayres, M.D., Lond.
Communicated by Joun Bisuor, Esq., F.R.S. Received Janu-
ary 11, 1855.

Arter some general historical remarks on the methods hitherto
employed in the investigation of the complicated phenomena of the
process of digestion, the comparatively small results obtained by
chemical analysis of the contents of the stomach, intestinal canal, and
of the evacuations, by Tiedemann and Gmelin, Berzelius, and others,
the author proceeded to demonstrate the necessity of a minute ex-
amination of the contents of the alimentary canal by the microscope,
and such chemical tests as we possess for the determination of the
changes of such articles of food as exhibit definite structure.

In order that we may ultimately arrive at a complete exposition
of the phenomena of digestion, he is of opinion that it will be neces-
sary to examine,—first, the structure of particular kinds of food,
then the changes produced in them by cooking, and lastly to trace
the changes they undergo at short intervals, through the alimentary
canal from the stomach to the rectum. The results of a series of

248 PROCEEDINGS OF SOCIETIES.

researches of this character on the changes in starch, and starch-
containing foods, are presented in this memoir.

The method adopted for the examination of the changes in starch
and starch-foods was as follows:—an animal was kept fasting
twenty-four hours, and afterwards confined to a diet consisting of
the starch or amylaceous food, with water, for five or six days, until
the debris of all other kinds of food previously taken were cleared
from the alimentary canal. At a determinate time, after a meal,
the animal was killed, the abdomen laid open as quickly as possible,
and ligatures placed at short intervals on the intestinal canal, from
the pyrolus to the rectum. 'The contents of the stomach and each
portion of the intestinal canal included between the ligatures was
then carefully examined. This mode of examination sufficed to
determine the changes which occur in the food during normal diges-
tion ; but other questions as to the particular secretion or secretions
by which the changes observed were effected.

The fluids poured into the alimentary canal are five in number,—
the saliva, gastric juice, bile, pancreatic juice, and finally, the intes-
tinal mucus.

The influence of the saliva is easily determined, by chewing the
particular food subjected to experiment, and keeping the mixture at
about 98° Fahr. ‘The combined action of the saliva and gastric
juice is seen in the contents of the stomach. ‘To determine the
action of the bile, the common bile-duct was tied, and to ascertain
the action of the intestiual mucus, it was necessary to ligature the
bile and pancreatic ducts. If the digestion of the substance is not
effected in the stomach, it is evident that it cannot be attributed to
the saliva or gastric juice; if the digestion is still effected in the
intestinal canal after ligature of the bile-duct, it cannot be attributed
to the action of the saliva, gastric juice or bile; if it still go on
after ligature of the bile and pancreatic ducts, the digestive power
must of necessity be referred to the action of the intestinal mucus,
provided no change has previously taken place in the stomach ; but
if the food passes unchanged after cutting off the supply of bile and
pancreatic juice, but proceeds after ligature of the bile-duct alone,
the act of digestion must be referred to the pancreatic juice.

The author first briefly describes the structure of the starches and
starch-containing vegetables employed in his experiments; then the
changes produced by cooking, and finally enters on a minute deserip-
tion of the changes observed in the experiments he performed on
normal digestion, and after cutting off the supply of bile and pan-
creatic juice.

The correct appreciation of the structure of the starch-granule is
of considerable importance in relation to these investigations, and
the author believes that he has been able to afford a satisfactory
solution of this vexed question. The changes observed during the
digestion of starch favour the original opinion of Leuwenhoeck, that
the starch-granule consists essentially of an investing membrane or
cell-wall, enclosing an amorphous matter, the true starch, which
strikes an intense blue colour with iodine ; and these changes also
support the opinion of Professor Quekett, that the concentric circles

PROCEEDINGS OF SOCIETIES. 249

seen on the starch-granules of many plants are simple foldings of
the investing membrane, leaving it still doubtful, however, whether
these concentric circles are not in the starches of some plants com-
posed of linear series of dotted elevations or depressions of the in-
vesting membrane.

By these experiments it was determined that the concentric circles
remain after the whole of the starch matter, colourable by iodine,
was removed, and that even then the characteristic cross and colours
were still seen when the granules were viewed by polarized light,
although more feebly than before; this result being probably due
to the lessened power of refracting light, after the removal of the
starch matter,

After describing the structure of the wheat-grain and flour, the
changes occurring in the wheat-starch during the manufacture of
bread are given in detail ; but the most interesting of the changes
produced by cooking are those seen in the boiled or roasted potato
and in the boiled pea.

In each of these the act of cooking effects two purposes :—it
causes great eilargement and physical change of the starch-granules,
and dissolves the intimate adhesion of the starch-cells, which after-
wards appear as ovid or globular. slightly adherent bodies distended
by the swollen starch granules, the outlines of which are indicated
by more or less irregular gyrate lines, produced by the mutual com-
pression of the starch-granules within an inelastic cell-membrane.

The starch-granules of the pea possess a much thicker investing
membrane than those of ihe potato, which causes their outlines to
remain much more distinct after the removal of the true starch sub-
stance during the process of digestion. The other structures seen
in the pea are carefully described ; the most curious among them
being the cells composing the external layer of the testa, which
bear so strong a resemblance to columnar epithelium of the intes-
tine, that they might be mistaken for the latter by an inattentive
observer.

The substances submitted to experiment were,—1, boiled wheat-
starch; 2, wheaten bread; 3, uncooked tous les mois; 4, boiled
tous les mois ; 5, boiled potato ; 6, uncooked peas ; 7, boiled peas ;
8, boiled peas after ligature of the bile-duct; 9, boiled potatoes
after ligature of the bile and pancreatic ducts. Several subsidiary
experiments were made to determine the action of the intestinal
mucus, the saliva, and the substance of the pancreas, on starch.

The conclusions at which the author arrives from the experiments
are,—

1. That the starch-granule is composed of two parts, chemically
and histologically distinet,—a cell-membrane and homogeneous
contents. The markings seen on many varieties of starch are re-
ferred to folds or markings of the investing membrane.

2. No perceptible change occurs in the starch, whether raw or
cooked, during its sojouru in the stomach of quadrupeds or the
ventriculus succenturiatus and gizzard of birds; all the granules
preserve their perfect reaction with iodine and their pristine ap-
pearance.

250 PROCEEDINGS OF SOCIETIES.

3. The conversion of boiled starch into dextrine and glucose is
chiefly effected in the first few inches of the small intestine, but it
continues to take place in a less degree throughout the entire intes-
tinal canal.

4. In the digestion of boiled wheat or other starch, or of wheaten
bread, the bulk of the mass rapidly diminishes in its passage through
the small and large intestines, so that it ultimately yields only a
small quantity of feecal matter. After being deprived of their con-
tents, the membranes of the granules shrink and shrivel up into a
minute granular matter, which constitutes the chief bulk of the
fecal evacuations after an exclusive diet of starch food.

5. The digestion of raw starch food (peas) in the pigeon or other
granivorous birds goes on much more slowly, and progresses pretty
equally throughout the entire intestinal canal. The starch-granules,
whether free or included in cells, become intersected by radiating or
irregular lines or fissures, more or less opaque or granular; they
also gradually lose their characteristic reaction with iodine; and
this important change, commencing at the surface, progresses
towards the centre, until the whole of the starch matter is removed,
leaving the starch-membranes often apparently whole, retaining
their characteristic markings. The fissured and granular condition
of the starch-granules is not due to their trituration in the gizzard,
but to the action of the intestinal fluids, since it was often seen in
granules enclosed in and protected by perfect starch-cells. In the
digestion of raw starch food, a considerable quantity always escapes
change, for many starch-cells and granules in the feces perfectly
retain the characteristic reaction with iodine.

6. As the starch remains unchanged in the stomach, its conver-
sion into glucose cannot be attributed to the saliva or gastric juice,
unless we suppose these fluids to remain inactive in the stomach,
and suddenly to regain their activity in the first part of the small
intestine. ‘The author found that the saliva was capable of effecting
the conversion of starch into glucose, but that the mixture of saliva
and gastric juice in the stomach did not possess that property even
after being rendered alkaline by carbonate of soda. It is probable
that the converting power of the saliva, as it flows from the mouth,
depends not on the true saliva, but on the buccal mucus; for Ma-
gendie found that saliva taken from the parotid duct was wholly in-
active, while the mixed saliva from the mouth effected the conversion
with great facility. Unless, then, the sublingual and submaxilliary
glands secrete a different fluid from the parotids, it is evident that the
activity of the saliva must be attributed to the buccal mucus.

7. The difference between the digestion of boiled and raw starch
in dogs is seen in the experiments on the digestion of boiled wheat-
starch, boiled tous les mois, and bread. In all these, some starch-
granules escape the action of heat and water, and remain in nearly
their pristine condition. These uncooked starch-granules undergo
slow and imperfect changes, being fissured, broken, and more or less
altered, but, in general, retaining their characteristic reaction with
iodine.

8. The conversion of starch into glucose is not effected by the

PROCEEDINGS OF SOCIETIES. 25f

bile, since after ligature of the common bile-duct, the changes occur
to as great an extent as when the bile passes freely into the intes-
tinal canal.

9. It is not due to the pancreatic juice, inasmuch as after ligature
of the bile and pancreatic ducts in the same animal, the digestion of
starch is still effected.

10. The only remaining secretion is the intestinal mucus, which
is especially abundant at the upper part of the intestiral canal; and
a further proof is afforded of the activity of the intestinal mucus
taken from the upper part of the duodenum above the entrance of
the pancreatic duct after ligature of this duct and the common bile-
duct, by its capability of converting a large quantity of fresh-boiled
starch into glucose out of the body.

11. In the cooking of starch-containing vegetables, such as pota-
toes and peas, the adhesion of the starch-cells is dissolved or weak-
ened so as to render them easily separable and amenable to the
action of the intestinal fluids. At the same time the starch-granules
undergo a large increase in bulk, distend the cells, and by their
mutual compression, their outlines present the appearance of gyrate
lines beneath the cell-wall. The cells seldom burst so as to emit
their contents, or present any appreciable opening through which
the intestinal fluids can directly penetrate. The author cannot
positively affirm so much of the starch-membranes, because these
are so extremely delicate that fissures might be invisible, but he
believes that in a great number the membranes remain entire.

12. If this be the case, the conversion of starch matter into
glucose must be effected by the permeation or endosmose of the
intestinal fluids through the invisible pores of two membranes, in
the digestion of the pea, the potato, and other similar foods, and the
glucose must escape through the same membranes by exosmose.

13. Before the conversion of starch into glucose, the amylaceous
matter contained in the starch is more dense than the intestinal
mucus in immediate contact with the cells, and an inward current
or endosmose is established; but after that conversion the syrupy
fluid is less dense than the mucus, and then an outward current or
exosmose occurs, by which the glucose escapes from the cells into
the intestine and is absorbed. If this be the case, as the details of
the experiments tend strongly to prove, a new and important fune-
tion is assigned to the intestinal mucus.

14, In normal digestion, chyme escapes very slowly from the
stomach into the duodenum, in small quantities, as it is detached
from the alimentary mass by the muscular movements of the stomach,
and this gradual propulsion often occupies several hours after a meal.
This slow propulsion is evidently intended to expose the commi-
nuted food fully to the action of the intestinal juices, and produce
an intimate mixture with them. The comparatively empty condi-
tion of the upper part of the small intestine, even during active
digestion, is thus fully explained.

15. If the food be too finely divided or incapable of a second
solidification in the stomach, it passes too rapidly into the first part
of the small intestine, is insufficiently mixed with the intestinal

252 PROCEEDINGS OF SOCIETIES.

fluids, and a considerable part escapes digestion. On the other
hand, if it enters the small intestine in masses incapable of reduction
by the muscular action of the parts or solution in the fluid, it tra-
verses the intestinal canal unchanged, except at the surface, which
is then alone exposed to the action of the intestinal fluids,

16. It is not necessary for the conversion of starch into glucose
that the fluids in the duodenum or other parts of the intestinal
canal should be alkaline, or even neutral, for in several of the expe-
riments the contents of every part of the alimentary canal had an
acid reaction.

17. The greater part of the intestinal mucus is not excremen-
titious, for little, if any, mucus is perceptible in the faeces in normal
digestion, except at their surface, whereas the greater proportion of
the contents of the small intestine consists of mucus. A consider-
able quantity of mucus is seen in the cecum, but it rapidly dimi-
nishes in the colon, and is scarcely detectible in the faeces, except
that on the surface, which is probably derived from the mucous
membrane of the rectum. The author raises the question, whether
one of the chief functions of the caecum is not to effect the conver-
sion of the intestinal mucus into some other substance capable of
re-entering the blood, and performing some ulterior purpose in the
animal economy.

18. In normal digestion, the separation of the epithelium of the
mucous membrane of the intestine is the exception instead of the rule,
as stated by some physiologists. The author questions the theory of
the detachment of the epithelium of the villi in each act of absorp-
tion, on the grounds that the presence of detached epithelium was
unfrequent in the whole course of his experiments; that epithelium
is readily detached by manipulation; that the continual reproduc-
tion of such a vast amount of cell-tissue must necessarily be accom-
panied by a vast expenditure of vital force ; and finally, that it is
not necessary, because fluids readily penetrate epithelial membranes.

19. The passage of a given food through the whole length of the
intestinal canal may occupy a comparatively short time, especially
when the animal is fasting. In one experiment, where a pigeon
refused food until the feeces contained no visible debris of previous
food, starch-granules were detected in the faces within two hours
after a meal, and this although the intestine of this animal is ex-
tremely narrow, and about a yard in length.

20. A remarkable circumstance in the digestion of starch or
starch foods is the constant presence of myriads of vibriones in the
lower part of the intestinal canal. They are generally first observed
in the lower part of the small intestine, as minute brilliant points,
just visible with a power of 600 diameters, in active move-
ment. They increase in numbers towards the cecum, in which a
large number of fully-developed vibriones are constantly seen.
These minute organisms increase in size and length in the colon
and rectum, and their fissiparous mode of propagation, first described
by the author in the ¢ Quarterly Journal of Microscopical Science,’
may be distinctly traced by examining the contents of these por-
tions of the intestine.

( 253)

ZOOPHYTOLOGY.

Unper the above not very scientific term, it is our intention
to devote in each number of the Journal one, two, or more
plates, as occasion may require, illustrative of new forms
belonging to the various classes of animals included under the
vague though popularly well understood term of Zoophytes ;
or, more particularly, of those among them which from their
size are necessarily subjects of microscopic research. These
are principally the Hydrozoa or Anthozoa hydroida of Dr.
Johnston. The Asteroid and Helianthoid divisions, scarcely
requiring the microscope for their determination, are not in-
cluded in our design.

In this department of the Journal we shall give—1. Figures
and descriptions of new or hitherto undescribed species from
any part of the world, as they may come under our observa-
tion or be furnished to us by others. We should therefore be
obliged to those who take an interest in this branch of Zoology
to aid us. by the communication of such observations, with
respect to new forms, as they may be desirous of presenting
to the world. 2. Observations on the anatomy and physiology,
&c., of the creatures comprised in the scope of our design,
illustrated or not. And 3. Notices of new species or original
observations published elsewhere.

As one very important, if not the most important, object of
this undertaking is to assist in the arriving ultimately at some
correct notions with respect to the geographical distribution of
these creatures—a problem apparently of the most curious
kind; it is highly desirable that any localities should be
assigned only upon good authority, and, if possible, accom-
panied with particulars as to the depth, bottom, and nature of
the surface upon which the polypidom or polyzoary grows,
Specimens for the purpose of representation, or drawings, will
be duly preserved and returned.

In the present number we commence with an enumeration
of Zoophytes of the two classes of animals above mentioned,
collected in the Arctic seas. The majority were brought
home by Dr. Sutherland, surgeon to H. M.S. Sophia ; others
by Sir E. Belcher, in what may perhaps be the last of Arctic
voyages ; and for two specimens we are indebted to our friend,
Mr. C. Peach, whose well-known accuracy is a sufficient
guarantee for the correctness of the habitat.

Even in this limited though interesting collection, it will
be seen that several new and remarkable forms are contained,

254 ZOOPHYTOLOGY.

and that other wide-spread species, though extending through
the torrid, despise the utmost rigours of the Arctic zone.

The arrangement of the Polyzoa, which it is purposed here
to adopt, is that according to which the marine Polyzoa are
disposed in the catalogue of those in the British Museum,
drawn up by Mr. Busk; the names of already-known species
are those there employed, where also figures of every species,
and the synonymy will be found.

Class. POLYZOA.
Order I. P. INFUNDIBULATA.

Sub-order 1. CHEILOSTOMATA.
§ 1. Articulata,
§§ 2, Bi-multiserialaria.

1. Fam. SALICORNARIADA.
1. Gen. Salicornaria, Cuv.
1. S. borealis, n. sp. Pl. L., fig. 1, 2, 3.
Front of cell elongated, slightly contracted below, arched above ; surface
and raised margin smooth ; avicularium on the front of the cell near the
bottom ; mandible triangular, acute, pointing downwards.

Hab. West Greenland, 73° 20' N. 57° 20' W., 6 to 10 fms. Dr. Suther-
land.

A very distinct and well-marked form. The polyzoary, which is com-
posed of club-shaped internodes, varying greatly in size, is irregularly
dichotomous, and from one to two inches in height.

Fam. CELLULARIADE.
2. Gen. Menipea, Lamx.
1. M. arctica, n. sp. Pl. 1., fig. 4, 6; 6.

Cells 3—9 in each internode, rhomboidal; aperture oval, contracted
below ; a marginal spine on each superiorly ; central cell at a bifurcation
mucronate at the summit. Ovicell smooth.

Hab. W. Greenland, 73° 20' N. 57° 20/ W., 6 to 20 fms. Assistance
Bay, 74° 50' N. 94° 16' W., 15 fms. Dr. Sutherland.

This species, which at first sight much resembles a Cellularia, differs
from all its congeners with which I am acquainted in the absence of any
avicularium on the anterior aspect of the cells. The lateral avicularium
is also frequently absent, and fragments thus unfurnished could only be
distinguished from the genus Cellularia by the rhomboidal form of the
back of the cells, and the absence of the perforations which exist on the
back of the cells in all species properly belonging to that genus.

Gen. 3. Scrupocellaria.
1. S. serupea? B. M. Cat., p. 24. Pl. XXI., fig. 1, 2.

Hab. Arctic sea. Sir E. Belcher.

The determination of this form having been made from only a very
minute specimen, growing on the inside of a valve of Terebratula psittacea,
is not absolutely certain, but I have little doubt of its correctness.

§ 2. Inarticulata seu continua.
§§ 1. Uniserialaria.
Gen. 4. Hippothoa, Lamx.
1. H. divaricata, Lamx. B.M. Cat., p.30. Pl. XVIIL, fig. 3, 4.
Hab. Arctic sea. On valve of Terebratula psittacea. Sir KE. Belcher.

ZOOPHYTOLOGY. 255

Fam. MEMBRANIPORID.
Gen. 5. Membranipora, Johnst.
1. M, Sophie, n. spz ,Pl. I.,, fig. 7.

An avicularium on either side, on the margin of the aperture. Two mar-
ginal spines on either side below the avicularia.

Hab. Assistance Bay (ut supra). On fucus. Dr. Sutherland.

The species to which the present form most nearly approaches are—

M. Flemingii, B. M. Cat., p. 58.
M., lineata, Linn.
M. fallax, Fleming.

From the first of these it is distinguished by the position of the avicu-
laria and the number and situation of the marginal spines. From the
second by the small number of the spines, and the position of the avicu-
laria. From the third, about whose distinctness Dr. Johnston, as I think
erroneously, appears to have doubts, by the number and situation of the
avicularia, and the number and situation of the marginal spines. Of the
three it most nearly approaches M, Flemingii, but I entertain no doubt of
its distinctness.

2. M. Flemingii. B. M. Cat., p.58. Pl. LXI., fig.2; Pl. LXXXIV.,
fig. 4, 5,6; Pl. CIV., fig. 2, 3, 4.
Hab. Arctic sea. Sir E. Belcher.
Gen. 6. Lepralia, Johnst.
1. L. hyalina, Linn. B.M.Cat., p.84. Pl. LXXXIL., fig. 1, 2,3;
Pl. ACV. he. 3,4, 53 PISCL, fie, ded.

Hab. Assistance Bay and W. Greenland (ut supra). On fucus. 6 to
20 fms.

This species, which is liable to numerous varieties, ranges from the
Arctic almost to the Antarctic seas, and abounds in all intermediate lati-
tudes. Its longitudinal range appears to be nearly equally extensive. It
occurs, for instance, in the Falkland Islands, Darwin ; Cape of Good
Hope, Harvey ; California, Dr. Sinclair ; and is common in the seas of
Europe.

2. L. scutulata,n.sp. Pl. II., fig. 1, 2.

Cells ovate; a scutiform or ovate space on the front, bounded by a
raised line, within which the surface is punctate. Mouth rounded above,
lower lip straight; a projecting rostrum below the mouth, sometimes
absent. Ovicell :

Hab. W. Greenland (wt supra). On fucus. Dr. Sutherland.

A very peculiar and distinct form. It isremarkable by the circumstance
that the cells gradually diminish in size from the centre to the periphery
of the patch formed by the polyzoary.

Fam. EscHaripa&.
Gen. 7. Eschara, Ray.
1. E. cervicornis, Ellis and Soland. B.M. Cat. Pl. CIX., fig. 7;

Pl. CXIX,, fig. 1.
Hab. Arctic sea. Sir E. Belcher.

The fragments collected, which are of some size, indicate that this
species flourishes in full vigour in the Arctic ocean.

2. #. 2 un. Spe
Hab. Arctic sea, Sir E. Belcher.

This form, the determination of which has not been made as yet with
sufficient certainty, appears to be new. The polyzoary is composed of

256 ZOOPHYTOLOGY.

slender cylindrical branches. Its description and representation are
reserved for a future occasion.

Sub-order II. CycLostomaTa.

Fam. TUBULIPORIDZ.
1. Gen. Tubulipora, Lamk.
1. T. ventricosa, n. sp. Pl. II., fig. 3, 4.

Polyzoarium sub-erect or recumbent attached by a contracted stem,
which rapidly expands above into a hollow calcareous vesicle, from which
the tubes project irregularly and of various lengths.

Hab. W. Greenland (wt swpra). On fucus. Dr. Sutherland.

Some of the simple forms of 7. serpens, or flabellaris, might on occasion
perhaps be confounded with the present species ; but it nevertheless, from
comparison of several specimens, appears to me to be quite distinct.
The polyzoary, which, though recumbent, is usually wholly unattached
above, is about 1-8th of an inch in length. It arises by a contracted por-
tion or stem, which is usually more or less curved or contorted ; and
speedily expands into a wide ventricose dilatation, in which the upper
tubes are immersed fora considerable part of their length. The tubes
project irregularly from all parts of the exposed aspect of the polyzoary,
and are themselves smooth or faintly ringed with lines of growth, whilst
the surface of the vesicular dilatation, which doubtless corresponds with
an ovicell, is finely punctate. When perfect the orifice of the tubes
exhibits a tooth-like projection on one or two sides.

2. Gen. Discopora, Fleming. PI. IIL, fig. 1.
1. D. ciliata, n. sp.

Orifice of tubes furnished with numerous slender spines.

Hab. Assistance Bay and W. Greenland. On fucus. Dr. Sutherland.

The figure of this minute species will be given in a subsequent plate.
It bears a remote resemblance to Discopora hispida (Tubulipora hispida,
Johnst.), but differs in the numerous slender spines with which the orifice
of the tubes is furnished.

Class. HYDROZOA.
Fam. SERTULARIADA.
Gen. 1. Sertularia, Linn.
1. S. polyzonias? Pl. II., fig. 5, 6.
Hab. Greenland. Peach.

From the small specimen thus characterized, and which is unfurnished
with the ovicell, it would appear that this cosmopolite species extends
even into the Arctic circle. It séems to abound in all parts of the world.

2. P. imbricata, n. sp. Pl. IL, fig. 7, 8.

Cells sub-opposite, very close, urceolate, wide and deeply immersed
below ; contracted and free for a short distance above ; margin of mouth
slightly raised on each side. Polypidom simply pinnate; pinne sometimes
forked, long and drooping. Ovicell rg

Hab. Greenland. Peach.

I am unable to reconcile this form with any other, and therefore venture
to give it the above designation.

( 257 )

ORIGINAL COMMUNICATIONS.

On the Structure of the Cutanrous Fotricies of the Toap,
with some ExeERtMENTS and OpseErvations upon the NaTuRE
and alleged Venomous Prorerttss of their SECRETION. By
GeorcE Rarney, M.R.C.S., Lecturer on Anatomy, &c. &c.,
St. Thomas’s Hospital.

From time immemorial a venomous quality has been attributed
to one or other of the secretions of the toad. Scarcely any one
who has spent much time in the provinces of this, and other
countries, has failed to hear of insiances of supposed poisoning
by this reptile: these accounts, however, have always been so
vague and imperfectly attested, as to obtain credit only among
the uninformed and superstitious classes of the people, so that
by enlightened persons the belief in the venomous powers of
the Toad has been regarded only as a vulgar prejudice. Such
were the doubts and opinions entertained upon this subject
as late as 1851, when they were said to be set at rest, and the
poisonous nature of the cutaneous secretion of the toad de-
monstrated by two French philosophers, MM. Gratiolet and
S. Cloez, who, by inoculating various animals with the secre-
tion in question, produced, according to the account given of
these experiments, most decided results, and, in some in-
stances, almost immediate death.

The experiments performed by these gentlemen were de-
scribed in many of the periodicals of this country. The
following are recorded in the ‘ Zoologist’ for November 1852 :
‘The first experiment was prosecuted on a little African
tortoise, which was inoculated with some of the toad-poison in
one of the hinder feet ; paralysis of the limb supervened, and
still existed at the expiration of eight months, thus demon-
strating the possibility of local poisoning by the agent. In
order to demonstrate whether the poisonous material spoiled
by keeping, these two gentlemen procured about twenty-nine
grains of the poison on the 25th of April, 1851, and having
placed it aside until the 16th of March, 1852, they inoculated
a goldfinch with a little of this material ; the bird almost
immediately died. Subsequently the investigators succeeded
in eliminating the poisonous principle from the inert matters
with which it is associated in the skin-pustules, and they
found that when thus purified, its effects are greatly more
intense than before.” Although the only way to investigate

VOL, III. s

258 RAINEY, ON THE STRUCTURE OF THE

this subject so as to lead to the decision of this long-contro-
verted question, is to repeat the experiments of these investi-
gators under, as nearly as possible, the same circumstances as
those under which they were performed, and note carefully
the results, still there are some objections to the conclusions
to which they seem to have arrived, which deserve to be
noticed. With respect to the first experiment, as an isolated
example, it, in my opinion, proves nothing positive, nor can
it have any weight, unless a similar effect can be produced
upon the same species of animal whenever the secretion is
applied in sufficient quantities. The alleged facts of this
secretion being, as it were, only a diluted kind of venom, and
containing a poison separable by chemical reagents, seem at
variance with the nature of organic animal venoms generally,
such as that of the Viper, the Bee, &c., which, in their natural
state, are sufficiently concentrated to produce the most unequi-
vocal effects as animal poisons. Besides, organic poisons of
this kind are most probably so easily decomposed, that the
chemical means employed to isolate their poisonous principle,
could scarcely fail to destroy its specific properties. But
before describing the experiments which I have performed
with the secretion of the toad’s skin, with a view to test the
accuracy of the above statements, I will give an account of
the structure of the follicles by which it is secreted, this
being the especial object of this communication, as .[ am not
aware that these organs have ever been described. ‘These
bodies (Plate XI., figs. 1 and 2) exist in the form of vascular
sacks, of various sizes, but largest about the sides of the head
and back; they are situated in the very substance of the skin
of this reptile; the vessels supplying them are altogether
distinct from the capillary network on the surface of the skin,
and have an especial arrangement and form of distribution by
which their presence can be recognized. These follicles,
though sufficiently characteristic, are difficult of demonstra-
tion, in consequence of being seen with perfect distinctness
only in the skin of the Toad when injected with colouring
matter and dried, and afterwards rendered transparent by im-
mersion in turpentine or Canada balsam. ‘This difficulty
proceeds from the opacity of the portion of skin situated
behind the follicle, preventing, whilst it is wet, the deep part
of the follicle from being seen, whilst the cutaneous capillary
network conceals the part of it nearest the surface. They are
of a globular form when distended, but somewhat flask-shaped
when empty (fig. 2). They range from 1-50th to 1-16th of
an inch in diameter. About the centre of the cutaneous sur-
face of each follicle there is an opening by which its cavity

CUTANEOUS FOLLICLES OF THE TOAD. 259

communicates with the skin: this opening is small, compared
with the size of the follicle, in the collapsed state of which it is
partially closed, in consequence of the approximation of the
folds of the internal membrane. This membrane, especially
in the larger follicles, is seen in a horizontal section to be
folded upon itself in a direction perpendicular to the surface of
the skin (figs. 3 and 4), so as to present a number of imperfect
septa projecting from the circumference of the follicle towards
the centre, with lateral depressions, or saculi, between them.
The whole of the internal surface of this membrane is lined
with epithelium, consisting of delicate, lozenge-shaped, very
flat cells (fig. 5), connected together by their edges, but pre-
senting each a very sharp and well-defined margin, and one
large nucleus. The nucleus contains minute granules, which,
as the cells degenerate into a state of decay, can be seen to in-
crease in size and distinctness, and ultimately to become broken
up into the minute oily-looking granules (fig. 1), of which the
secretion of the follicles is chiefly made up. The vessels of
these follicles consist of capillaries of a larger size than those
forming the plexus on the surface of the skin, and with much
smaller areole; they do not follow accurately the folds of
membrane projecting into the cavity of the follicles, but
simply pass over, and on the outer side of these folds, so as to
encircle the entire sack with a single layer of capillaries. The
_ afferent and efferent blood-vessels of this plexus are connected
with its deep surface, which, being generally only two in
number, an artery and a vein, and give to the follicles, when
minutely injected, very much the appearance of a Malpighian
body highly magnified.

These follicles are entirely surrounded with the white fibrous
tissue of which the skin is composed, excepting where they
open on the surface. These fibres are disposed in two
planes, one parallel with the surface, the other perpendicular
to it; the former are by far the most numerous, and constitute
the chief thickness of the skin; the latter are comparatively
few, and only partially distributed, being collected into bands
placed at nearly equal distances apart, which, extending through
the entire thickness of the skin, from its deep to its superficial
surface, draw, as it were, the fibres of the first set in these
situations more firmly together; and thus producing a closer
approximation of the fibres, and a corresponding diminution
in the thickness of the skin at these parts, they cause the
horizontal cellular fibres to take an undulating course.

Between the part of the true skin just described, and its
epidermic surface, and immediately beneath the cutaneous
capillaries, there is a layer of earthy matter, varying in thick-

s

260 RAINEY, ON THE STRUCTURE OF THE

ness in different parts of the animal, but present, I believe, in
all. .This part of the dermis is composed of irregularly-
shaped masses of a semitransparent and_highlv-refractive
material (fig. 4), looking like broken fragments of crystal or
glass, lodged in cellular depressions of the true skin. Where
the secreting follicles are situated, this earthy matter is placed
superficial to them, so that their openings have to penetrate a
layer of earthy substance, in order to reach the surface of the
dermis. This part of the skin, when acted upon by acids, under
the microscope is seen to effervesce briskly, and after all the
earthy material is dissolved out, a membranous or animal
basis is left. Probably this part of the skin in the Toad is
analogous to the scaly covering of the Chelonian reptiles.
According to Dr. Davy’s analysis of the skin of the toad, it
contains phosphate and carbonate of lime, and carbonate of
magnesia. No organs like those which I have described as
the cutaneous follicles of the Toad, exist in the integument of
the Frog or Water-newt. In these reptiles the skin is much
more simple, and all the vessels supplying it go into the com-
mon superficial plexus of the dermis. I have not examined
the skins of thase lizards whose habits resemble those of the
toad, for the purpose of determining whether the same kind
of follicles exist also in them.

With respect to the chemical and physical properties of the
secretion of the Toad’s skin, Dr. Davy observes, in a paper
contained in the ‘ Philosophical Transactions,’ for 1826, that
the greater part of it is soluble both in alcohol and in water ;
that the substance obtained by evaporation, both of the
aqueous and alcoholic solution, is slightly yellow, and has a
faint and peculiar smell ; that when heated it readily melts,
and burns with a bright flame, but without emitting an am-
moniacal odour; also that the secretion is slightly bitter,
and very acrid, acting on the tongue like the extract of
aconite, and even occasioning a smarting sensation when
applied to the skin of the hand, which lasted for two or three
hours ; that it does not affect the colour of litmus, or tur-:
meric paper. This secretion, though possessed of these
decidedly acrid properties, even in a much greater degree than
the poison of the most venomous snakes, was not found by
Dr. Davy to produce any injurious effects when applied to a-
wound ona Chicken, made with a lancet dipped in it; and.
hence it seems to be endowed merely with irritating qualities, :
and not to possess the venomous properties attributed to it by
the French investigators.

The experiments which I have performed upon living ani-
mals with this secretion, have in no instance agreed in their

CUTANEOUS FOLLICLES OF THE TOAD, 261

results with those recorded by Gratiolet and Cloez. I ap-
plied some of the fresh secretion to a recent wound on the ear
of a Kitten, but it produced no sensible effect. I also inocu-
Jated Toads both with their own secretion, and that taken
from other toads, but it did not affect them. White mice
were inoculated with it in various ways, but they sustained no
apparent injury. In order to secure the perfect contact of the
secretion with the wounded surface, I immersed a piece of
thread in the fresh fluid of a follicle, and passed it through
the skin of a Mouse in the manner of a seton, where it re-
mained for several days, but without producing any perceptible
harm to the little animal. It is remarkable that such differ-
ent results should be obtained from the same description of
experiments, and it is very difficult to reconcile these dis-
crepancies. It is true that the single example which Dr.
Davy has recorded, and those which I have mentioned, are
on the negative side of the question, and therefore cannot be
looked upon as so conclusive as those on the positive side.
However, [ think these experiments are sufficient to throw
considerable doubt upon the accuracy of the conclusions of the
French investigators, and to bring the question into the same
state of uncertainty that it was before their observations were
published, where it must remain until these authors shall be
able so to conduct their experiments, as at all times to pro-
duce the effects they have described, or, in case of failure, to
give a satisfactory explanation of its cause. There is one
consideration which, as mere circumstantial evidence, may be
mentioned in opposition to the view of the intensely-venomous
power of the secretion of the Toad’s skin, and that is its gene-
ral diffusion over a large part of the body, whilst in all those
animals which are decidedly provided with a specific venom,
and not a mere irritant, the frightful apparatus which produces
and applies it, is well known te occupy only a very confined
locality.

From what has been stated it appears, then, that though the
specific character of the secretion in question, as a venom, is
very questionable, yet that it certainly does possess an irri-
tating quality, as was apparent from its action when applied
to the skin, and more especially to the tongue; hence Dr.
Davy thinks that its principal use is to defend the reptile
against the attacks of carnivorous animals. The extremely
dense structure of its dermis, approaching in its composition
to that of bone, is, I think, somewhat in favour of this opi-
nion, as affording also, more or less, a means of protection
and defence. Dr. Davy also considers that, as the secretion
contains an inflammable substance, it may serve to carry off a

262 CUTANEOUS FOLLICLES OF THE TOAD.

portion of carbon from the blood, and thus be auxiliary to the
function of the lungs. In support of this idea the same
author observes that each of the pulmonary arteries of the
Toad divides into two branches, one.of which goes to the lungs,
the other to the cutis, ramifying most abundantly where the
largest follicles are situated, and where there is a large venous
plexus, seeming to indicate that the subcutaneous distribution
of the second branch of the pulmonary artery may further aid
the office of the lungs by bringing the blood to the surface to
be acted upon by the air. However, it seems to me that if
these follicles aid at all the lungs, it can only be by elimi-
nating carbon set free in other organs of the body, and then
conveyed into the blood, from whence they afterwards ex-
crete it; as the deep position of their capillaries, and the
secretion with which they are always more or less thickly
covered, will make them inaccessible to the atmospheric
air, and therefore, in this respect, render them altogether
different from the cutaneous capillaries which are placed su-
perficial to the earthy layer of the dermis, and in which the
blood is perhaps acted upon, as above intimated. But I
cannot help thinking otherwise than that these follicles have
something to do with the absorption, and more especially
with the retention, of the fluid which, in this class of reptiles,
is taken into the system by the skin. In the Frogs there is a
superficial plexus of capillaries the same as in the Toads, by
which the absorption of the fluid in contact with the surface,
can take place equally in either case ; but in the former ani-
mal there are no cutaneous organs which could in any manner
aid in the retention of that fluid, so that this reptile requires
more frequently than the toad a fresh application of moisture
to its surface; and besides, if the Frog be exposed to the
absorbent power of dry mould, as the Toad frequently is, the
greater part of the fluid contained in its vessels will imme-
diately pass off through the skin into the dry earth in conse-
quence of its greater capillary attraction, and the animal will
very soon die from a kind of inanition. This fact I have
verified by placing fine dry sand in contact with the skin of
Frogs, which so rapidly absorbs their moisture that they die
in a few minutes. The contents, also, of the follicles of the
toad, mixing with the dust and other extraneous substances
constantly in contact with its skin, especially as this secretion
is of a very glutinous nature, and has a tendency to coagulate
when wetted, may possibly form a coating on its external sur-
face, and thus tend to diminish evaporation ; and in this way
it may assist in retaining the fluids absorbed into the body,
and in preventing its desiccation, and thus furnish another

REPRODUCTIVE ORGANS OF FUNGI. 263

means of adapting this animal to the physical and physio-
logical states and conditions under which it is constrained to
live, and to perform its part in the accomplishment of that one
universal and wise purpose for which this much-despised rep-
tile, in conjunction with all other living beings, was designed
and created.

On the RerropuctiveE Oreans of certain Funei. By FRreps-
RICK CurrREy, Esq., M.A.

Tue existence of sexual organs in the lower orders of plants
is a question which of late years has attracted much attention
amongst botanists, and it is one upon which the powers of the
microscope have been brought to bear with the happiest
results.

The investigation has already been carried sufficiently far
to show that many of the plants hitherto ranked in the Order
of the Cryptogamia can with difficulty be denied the right of
being considered phanerogamic ; and there seems good reason
to hope that before many years have elapsed, the term crypto-
gamic will have ceased to be applicable to any portion of the
vegetable world.

It is hardly too much to assert that sexuality is already
established in the Fucacee and Characee amongst the Thal-
logens, and in the Liverworts, Scale-mosses, Urn-mosses,
Club-mosses, Horse-tails, and Ferns amongst the Acrogens,
although there are not wanting botanists of eminence wha
either deny the fact, or, at least, admit it only with the doubts
of an imperfect faith.

In Lichens, M. Tulasne has demonstrated the existence of
certain organs to which he has given the name of spermogonia.
These spermogonia are the small black specks seen on the
shields of Lichens, and are small conceptacles, or cases, con-
taining a prodigious quantity of minute spore-like processes,
to which the name of spermatia has been given. The sper-
matia are very minute linear bodies, sometimes curved and en-
dowed with molecular movement. They are produced either
upon the apices of the cellules which form the walls of the sper-
mogonium, or sometimes laterally from moniliform filaments
or other processes which line the cavity of the spermogonium.

The functions of the spermatia are as yet unascertained,
although from their universal presence, and the circumstance
of their appearance prior to the perfect, or the casporous
fructification, it 1s suspected that they may eventually prove
to be the male organs of that class of plants.

264 CURREY, ON THE REPRODUCTIVE

There are many Fungi in which bodies analogous to the
spermogonia and spermatia of Lichens are found to exist, and
as far as present observation has extended, these bodies are
found to precede the formation of the perfect spores. The
genus Aicidium is very favourable for an examination of these
organs. The spermogonia occur in spring upon those parts
of the plants upon which perfect 4£cidia are afterwards
found ; they are in the form of minute punctiform specks,
covering the pale or red spots upon which the cidia are at
a later period produced. A microscopical examination of
these specks shows them to be globular bodies, open at the
top, having their walls composed of densely-mterwoven
threads originating from the mycelium, and containing “in
their interior other threads converging towards the centre of
the spermogonium, and bearing spermatia at their apices.
The spermatia are produced in great abundance, and form a
granular mass, filling the hollow of the spermogonium. The
upper threads of the walls (namely, those which are situated
next to the apicular opening of the spermogonium) are some-
what more upright than the others, and are directed towards
the epidermis of the surface of the leaf; and hy the growth
of these upper threads and the increase of the granular mass
of spermatia, the spermogonium increases in size, raises, and
eventually breaks through the epidermis, the outermost
threads forming a small red funnel-shaped tuft, through
which the spermatia eventually escape, and are dispersed
around the spermogonium, After the ripening of the sper-
mogonia, the perithecia of the true £cidia are formed on the
same mycelinm, and the spermogonia then decay.

Spermogouia, such as those just described, are not confined
to the genus 4icidium ; they are common to other genera in
the tribe of the Uredinee, occurring in Ceoma, Restelia,
Peridermium, Phragmidium, Triphragmium, and Pucctnia.
In Cystopus, Melampsora, Coleosporium, and Uromyces, they
have not as yet been ascertained to exist. Nor are spermo-
gonia peculiar to the tribe of the Uredinee ; they occur with
certain, but not essential differences of structure, in many
other Fungi, It Las been shown by the observations of Fries,
Tulasne, and other my-vologists, that several sorts of Fungi,
long supposed to form distinct genera, are, in fact, only early
states of other well-known plants: thus the genera Septoria,
Cytispora, Nemaspora, Hendersonia, and others, are now con-
sidered to be the spermogonia of species of Spherie ; Melas-
mia is supposed to be the spermatiferous state of Rhytisma ;
Leptostroma probably of Hysterium, Phacidium, ete... .

In a paper published in the ‘ Annales des Sciences’ for

ORGANS OF CERTAIN FUNGI. 265

1853, M. Tulasne has given a description of a considerable
number of Fungi belonging to the order of the Discomycetes,
in which he has observed spermatia; and he states that he
has also discovered them in several of the Pyrenomycetes.
The details of his observations on the latter tribe have not, as
far as | am aware, been yet made public, although referred to
in a paper in the 15th volume of the 3rd series of the
‘Annales des Sciences.’

I have already stated that the functions of the spermatia of
Lichens are not yet ascertained ; and as in the vast family of
the Fungi there are as yet comparatively few species in
which these organs have been certainly observed, it is
obvious that we are not yet in a position to hazard an
opinion as to the office which they fulfil in the latter tribe.
All mycologists will, I am sure, agree with M. Tulasne, who
has remarked that the present aim of observers should be to
ascertain whether spermatia exist in a sufficient number of
species to consider them constant or common to all. The
subject of their action, supposing them to be male organs,
might be afterwards considered.

Whilst the observer is occupied in investigating the nature
of the spermatia, he will naturally and necessarily be led into
an inquiry into the nature of two kinds of reproductive organs
distinct from the spermatia, and which are called stylospores
and conidia.

It has been found that in some ascigerous Fungi, that is,
Fungi in which the normal fructification consists of spores
contained in asci or thecw, there are produced other naked
spores which are borne upon pedicels of greater or less
length, and it is these naked spores to which the name of
stylospores has been given. The cellules or pedicels upon
which the stylospores are borne, are analogous to the basidia
of the Agaricini: they are sometimes enclosed in a concep-
tacle, or case, which is called a Pyenidium.

Size and complexity of structure generally distinguish the
stylospores from the spermatia; but there is no very definite
line of demarcation, so far as regards structure, between sper-
matia and small simple stylospores.

The term conidia was applied by Fries to all reproductive
bodies not being norma] spores.

Tulasne restricts it to Gemme@ properly so called, that is to
say, reproductive cellules growing directly from the my-
celium.

I will now proceed to state the result of some observations
with which I have lately been occupied, bearing upou the
matters above alluded to.

266 CURREY, ON THE REPRODUCTIVE

1. Spheria herbarum Pers.—This very common but beau-
tiful Spheria is to be found abundantly in spring in the form
of small black specks upon the dead stems of herbaceous
plants. About the beginning of March in the present year,
I observed that the dead stems of some plants of Senecio
Jacobea were covered with a Fungus, the perithecia of which
formed minute black spots so small as not to be visible with-
out close inspection. In Plate XII., fig. 1, one of these peri-
thecia is represented with its mycelium magnified 110 dia-
meters, and fig. 2 represents a transverse section of a similar
perithecium, the interior being filled with small spore-like
bodies proceeding from the somewhat-pointed cells which
lined the cavity of the perithecium. According to the prin-
ciples of classification hitherto adopted, the plants would
have belonged to the genus Spheropsis ; but being desirous of
ascertaining whether it might not in fact be only an early
state of some other Fungus, I placed some pieces of the dead
stems upon damp Sphagnum moss, and covered them with a
bell-glass. In about a fortnight I found the under surface of
the stems (7. e., that part of them which had lain in contact
with the damp moss) covered with a crop of small black
Spherie. 'There was, therefore, some reason for supposing
that the Spheropsis was only a predecessor of the Spheria ;
but as there were three, if not four, different species* of the
latter, it would have been impossible to determine to which of
them the Spheropsis belonged, had it not been for the form of
the mycelium. In examining the Spheropsis, 1 had particu-
larly observed its mycelium, which was unusually large com-
pared with the size of the perithecium, and had moreover the
peculiar knotty appearance shown in figs. 1 and 2. Upon
comparing this mycelium with that of Spheria herbarum, the
two appeared identical; and as the same mycelium was not
to be seen in connection with the other Spheria, it seems
fair to conclude that the supposed Sph@ropsis was the sper-
mogonium of Spheria herbarum. The question then arises
whether the spermogonium in this case be a distinct organ on
the same mycelium, or whether the same perithecium pro-
duces in the first instance the spermatia, and subsequently
the perfect fructification, that is, asci containing sporidia. In
the _dicidia, as we have seen, the spermogonia are quite

* The species appeared to be the following :—Spheria comata, capil-
lata, herbarum, and complanata. I doubt if the two former are distinct ;
I found the sporidia precisely alike, and the only difference was in the
colour of the hairs on the perithecia, which were black, or nearly so, in
S. comata, and greenish in S. capillata. The difference in the colour of
the hairs would hardly justify a separation of the species.

ORGANS OF CERTAIN FUNGI. 267

distinct from the true A‘cidineous perithecia; but there are
some discomycetous Fungi, for instance, Peziza benesuada,
Cenangium Frangule, and Dermatea carpinea, in which the
spermatia and the perfect fructification occur in the same
part of the plant. From what will be stated hereafter, with
regard to Spheria complanata, it would seem that in the latter
plant the same perithecium produces spermatia and asci suc-
cessively ; and if it be allowable to assume a law for the genus
from what occurs in one species, it would follow that the
spermogonium in Spheria herbarum is not distinct from the
true perithecium.

It will be proper here to mention certain other reproductive
bodies which I have observed in Spheria herbarum ; they
are somewhat irregular in colour, shape, and size, and grow
directly from the mycelium. In colour they differ much
amongst one another, varying from a dull brown to the bright
yellow of the normal sporidia. In fig. 3 several of these bodies
are represented ; some of the larger “of them strongly resemble
the spores of a Stemphylium or Sporidesmium, and others again
are hardly distinguishable from the regular sporidia of Sphe-
vias herbarum. © ‘These bodies come under*M:. Tulasne’s-defini+
tion of conidia, being gemme or buds proceeding directly
from the mycelium.

Those represented in fig. 8 occurred in company with full-
grown, ripe perithecia ; ; but their growth commences at a very
early period, and contemporaneously, or nearly so, with the
appearance of certain other bodies, which may lea perhaps,
have to be ranked amongst the varieties of fruit of Spheria
herbarum; these last-mentioned bodies are globular vesicles,
which proceed from the end of short branches of the myce-
lium in its earliest stage.

The sporidia of Spheria herbarum appear to have a great
facility of germination, throwing out filaments from several
different partitions of the sporidia. On the 2nd of May in the
present year, I had placed a section of a perithecium upon a
slide under a piece of thin glass, for examination in the usual
way, and the fruit being particularly fine, I put the slide upon
damp moss under a bell-glass, with the view of keeping the
object moist until a drawing could be made. The weather
was very unfavourable for germination, for the long-prevalent
east wind was on that day more than ordinarily harsh and
cutting, and Fahrenheit’s thermometer fell at night to 26°;
moreover the room in which the slide was kept had a northern
aspect, no fire, and the character of being at all times cold.
Notwithstanding these circumstances I found, upon examining
the slide the next morning (May 3), that the ‘sporidia had ger-

268 CURREY, ON THE REPRODUCTIVE

minated in the greatest abundance ; and not only had the free
sporidia—those which had escaped from their asci—thus
sprouted, but those which were still enclosed had also sent
forth their germ-filaments, which had penetrated the mem-
brane of the asci in all directions.

In fig. 4, I have represented one of the asci in which nearly
all the sporidia have begun to grow, and other asci in the
neighbourhood were even more densely covered with filaments
than the one shown in fig. 4. On the following morning
(May 4) the germ-filaments had reached a considerable length,
and had become branched and indistinctly septate in several
places (see figs. 5 and 6), as indeed was the case on the pre-
vious day with some of the more advanced shoots. At one
point the germ-filament had protruded short branches at right
angles to the main filament on either side (see fig. 5), and at
the end of each of these short branches was seated one of the
globular vesicles above mentioned. The nature of these
vesicles is uncertain; but it is not improbable they may be
homologous to what have hitherto been called the spores of
Tubercularia vulgaris, this latter plant being now considered
to be nothing more than the mycelium of a Spheria (S. cinna-
barina), and the so-called spores to be, in fact, only conidia
of that Spheria. I have as yet only seen these globular vesicles
in the two instances shown in fig. 5, but I have observed other
branches of the mycelium which became rounded at the apex,
and in which a nucleus was formed. After the formation of
the nucleus a fresh germ was thrown out (see fig. 7). Some-
thing similar to this has been observed by M. Tulasne in the
Uredinee, in which the germ-filament has become inflated,
and then thrown out a fresh shoot.*

In fig. 8 is represented a cellular body, which was attached
to the mycelium by a delicate stalk, the stalk itself being
attached to the side of the body. There seems no reason to
doubt that this body, differing as it does from some of those
shown in fig. 3, only in being of a much paler colour, repre-
sents a young state of one of those organisms. I first observed
it about nine days after the commencement of germination, at
which time also the germ-filaments had in places begun to
form a network by a kind of conjugation, which had taken
place between the germ-filaments proceeding from different
sporidia. é

It follows from what has been said, that if we consider the
spermatia as reproductive bodies, in the proper sense of the
word, as it is applied to seeds or spores, 7. e., as fruit, then
Spheria herbarum has four distinct sets of reproductive organs.

* See vol. ii. of the ‘ Annales des Sciences’ for 1854.

ORGANS OF CERTAIN FUNGI. 269

If, on the other hand, the function of the spermatia is not re-
productive but sexual, or impregnative, we still have three dis-
tinct forms of fruit, viz., the sporidia contained in the asci
(see fig. 9),* and the two forms of conidia (figs. 3 and 5),
which grow directly from the mycelium.

2. Spheria? complanata, Tode.{ This Spheria is as com-
mon as the preceding one, growing abundantly in spring upon
the dead stems of umbelliferous plants. The spermogonia, or
rather spermatiferous perithecia, are shaped like a dome, with
a pointed conical ostiolum. They are distinguishable from
the ascigerous perithecia by their full, rounded appearance,
the latter being depressed or collapsed, affaissé, as the French
say.

It would hardly be possible in this case to prove directly
that the spermogonia and perithecia proceed from the same
mycelium. In the A4cidia, which grow upon the soft parts
of plants, it is possible by maceration and careful dissection
to obtain ocular demonstration of the occurrence of the sper-
mogonia and perithecia upon the same mycelium; but this
cannot be effected with the hard, dead stems of Umbellifers,
and the proof of the connexion between the spermogonia and
perithecia must therefore be sought for in other evidence.

Now I found both in the spermatiferous and ascigerous
perithecia some peculiar-shaped organisms, the nature of
which I am at a loss to conjecture. These bodies consist of a
stem, crowned by three cellular, sometimes septate, prolonga-
tions, with a seta on either side. One of them is represented
at fig. 11, which will give a better idea of them than any
written description. But irrespective of these curious pro-
cesses which, occurring as they do in both the spermatiferous
and ascigerous perithecia, seem to point to a connexion
between the latter, I found in one instance the spermatia
and asci, contained in the same perithecium, a direct proof that

* The asci and sporidia of Spheria herbarum vary much in size. In
fig. 9 are represented two extremes. In the one the ascus is short and
broad, and the sporidia fill the whole of it. In the other the ascus is
much elongated, and the sporidia, which are smaller, are collected at the
upper end of the ascus. I find the latter form the most frequent.

t Iam doubtful whether I have named this Spheria rightly. I find
two plants, in which the perithecia are precisely alike, both answering the
description of Spheria complanata, but the sporidia are widely different.
In fig. 10 I have represented an ascus, with sporidia, of the plant to which
the above observations relate. The asci of the other Sphevia are narrower,
and the sporidia are curved, acuminate at each end, triseptate, with a
swelling at the second joint. The description of the sporidia of S. compla-
nata, given in the Annals of Natural History under S. modesta, does not
accord with that in the English Flora, where the sporidia are said to be
oblong-elliptic.

270 CURREY, ON THE REPRODUCTIVE

both of these latter bodies are the produce of the same con-
ceptacle or case. Can it be that the cellular processes above
mentioned (such of them at least as are not septate) are young
asci, to be fertilized by the action of the spermatia? This
is a mere speculation, but it is not an impossibility.

The spermatia of S. complanata are elliptical, about 1-4300th -
of an inch long, with an indistinct sporidiolum at each end.

3. Spheria sinopica; Fries, Elenchus Fungorum, vol. ii,
p- 81. This Spheria, one of the Cespitose, grows in tufts
upon a stroma which is not always perceptible, and which
Fries considers to be identical with Tubercularia sarmentorum.
If this be so, the spores of this latter fungus must be looked
upon as the conidia of the Spheria, in the same manner as
the spores of Tubercularia vulgaris are considered to be the
conidia of Spheria cinnabarina. The sporidia of Spheria
stnopica are elliptical, uniseptate, and slightly constricted at
the septum. They frequently have a sporidiolum in each
partition. Besides these normal sporidia, I have found in
many plants of S. sinopica an immense mass of minute
bodies, which I do not hesitate to consider as spermatia.
These bodies are excessively minute, elliptical or sub-cylin-
drical, many of them not exceeding 1-6500th of an inch in
length, and endowed with molecular motion. In most of the
plants which J examined, these spermatia occurred in conjunc-
tion with the regular sporidia, but some specimens contained
spermatia alone. In these latter specimens the perithecia were
rather of a pyriform shape, not depressed as is the case with
the perfect perithecia of S. stnopica. This fact is precisely
analogous to what occurs in S. complanata, where the per-
fect perithecia are, as we have seen, flattened or collapsed,
whilst the spermogonia are swollen and shaped like a dome.
The spermatia of S. sinopica appear to be born upon fine,
simple, densely-crowded filaments, which line the cavity of
the spermatiferous perithecia. This Spheria, it will be seen,
affords another instance, in which it is clear that what might
be called the spermogonium is, in fact, the true thecasporous
perithecium of which the spermatia are the primary produce,
and the asci and sporidia a subsequent fructification, whether
produced or not by the fertilizing influence of the spermatia
time will probably show.*

* In the ‘ Annals of Natural History’ for June, 1854, Messrs. Berkeley
and Broome have described, as a new species, a Sphwria to which they
have given the name of Spheeria (Nectria) inawrata. It is stated to have
been found near Bath by Mr. Broome, and at Shooter’s Hill by myself ;
but there has been some mistake. The Sphwria on holly which I found

at Shooter’s Hill, and of which I sent specimens to Mr. Berkeley, is
certainly Spheeria sinopica ; at least the plants which I retained have not

ORGANS OF CERTAIN FUNGI. 271

4. Spheria Cryptosporti, n. s.—This species has not, as far
as I am aware, been hitherto described, and may be thus
characterized. 9

Obtecte ; Peritheciis sparsis vel aggregatis globosis aut
sub-globosis, collo elongato corticem perforantibus ; nucleo
albido ; ascis late obovatis, sporidiis simplicibus linearibus,
utriusque obtusis plus minus arcuatis circiter (00036 uncie
longis.

I believe this Spheria to be the perfect state of Cryp-
tosporium vulgare, on the evidence of the following facts. In
April of this year I placed in damp moss some twigs of alder
upon which Cryptosporium vulgare was growing; in about a
month afterwards the long black ostiola of the above Spheria
had protruded themselves through the bark. Upon examining
the fructification under the microscope, the resemblance of
the sporidia of the Spheria to some of the naked spores of
Cryptosporium vulgare (viz. those which were least strongly
eurved) was so striking that a possible connexion between the
Spheria and the Cryptosporium naturally suggested itself.
Some of the perithecia, which were in a young state, con-
tained an immense quantity of oily matter, and small granules
in a state of active motion, some densely interwoven threads
attached to the walls, and a very few sporidia resembling those
of Cryptosporium vulgare, and which had probably formed the
terminal joints of the threads just mentioned.

In another of these young perithecia I observed the terminal
joint of two of the threads, which had assumed the shape
shown in fig. 12 (4, c). One of them contained a moniliform
row of oil globules, and was evidently the earliest state of
other young asci, fig. 12 (a), which occurred in the same
perithecium. Jn the more advanced plants the perithecia con-
tained perfect asci, which, with one of the escaped sporidia,
are shown at fig. 13 (a, 6). Even when the asci within the
perithecia were still young, or at least not fully ripe, the
ostiola were surrounded with a milky substance ejected from
the perithecia, which consisted principally of free sporidia,

the dimorphous ascigerous fructification, they have no fails to the sporidia,
and differ in no respect from Spheria sinopica. From the description of
Spheria inaurata it seems to be identical in its external characteristics
with Spheeria sinopica, but the fructification of the former is very peculiar,
It consists of two sets of asci differing in form, and containing different
sporidia ; the larger asci are clavate, and contain small curved sporidia
not exceeding *00015th of an inch; the smaller, cylindrical asci, contain
eight elliptic uniseptate sporidia -0005—*0006th of an inch long, fur-
nished with a tail at either end in the form of a delicate hyaline appendage.
The two sorts of asci are figured in the ‘ Gardeners’ Chronicle’ of the 22nd
July, 1854, where a full description of the plant will be found.

272 CURREY, ON THE REPRODUCTIVE

with an occasional ascus intermixed. Again, upon taking a
section of one of the plants of Cryptosporium vulgare which
occurred upon the same twig, I found a very few asci, iden-
tical with those of the Spheria, intermixed with the naked
spores of the Cryptosporium.

One of these asci, which is in a very early stage, is shown,
fig. 13 (ce). The membrane was of extreme tenuity, and in
the middle was a linear mass of granular protoplasm, partly
divided in a longitudinal direction by a dark line, which,
however, did not traverse the whole length of the granular
matter. Another of the asci, fig. 13 (d), contained a much
larger quantity of granular matter, still apparently in one
mass, but deeply marked and furrowed. ‘There can be no
doubt that in the two asci just mentioned the sporidia were in
process of formation, and.that the lines and furrows pointed
to the directions in which the granular mass was eventually to
become separated, so as to form the eight perfect sporidia.

The above observations would be conclusive as to the iden-
tity of the Spheria and the Crytosporium, were it not for the
possibility that the sporidia, forming the milky mass around
the ostiola, might have been contained in asci which had been
dissolved within the perithecium, although from the young
state of the included asci this is not probable ; and in the case
of the section of the Cryptosporium, inasmuch as I did not
see the asci in situ, it is possible that the few which occurred
might have been adhering to the scalpel or brush used in a
previous examination, although I have no reason for supposing
that such was the case.

I think it will be admitted that the above facts afford strong
evidence to show that Cryptosporium vulgare and Spheria
Cryptosporti are states of one and the same plant. It is difficult
to suppose that the former is the young state of the latter; it
would rather seem that the same conceptacle has the faculty
of producing both naked spores and asci, and that it depends
upon circumstances, possibly atmospheric, whether the one or
the other be produced. It seems to me not improbable that
the spores of the Cryptosporium may in some instances be
converted into the asci of the Spheria. I have seen what
seemed to be a common spore of the Cryptosporium, but which
had a very delicate hyaline investment, and the bodies shown
in fig. 13 (c) and (d) may be only more advanced steps in the
process of conversion. Some objection might be raised to this
view on account of the shape of the Cryptosportum spores, most’
of which are strongly curved and acuminate at either end, but
on the other hand the spores vary greatly in size and shape,
and some occur plentifully, which are quite undistinguisbable

ORGANS OF CERTAIN FUNGI. 273

from the sporidia of the Spheria, see fig. 13 (b, f); the
former of which represents a sporidium of the Spheria, the
latter a spore of the Cryptosporium.*

Cryptosporium vulgare is a plant not unfrequently found
upon beech and alder twigs, and I much hope that some
reader of this paper will repeat the above observations, which
may be done without difficulty or trouble. The simplest plan
for keeping the bed of moss in a proper state is to fill a com-
mon flowerpot about one-third full of crocks for drainage,
and to fill the rest of the pot with damp (not wet) sphagnum
moss; the moss should be kept damp by occasionally putting
water into the pan in which the pot stands, and not by pouring
it over the top of the moss; the pot should be kept covered
with a bell-glass. Many a fungus may be grown in this
manner which would not have a chance of coming to maturity
in such cold dry weather as we have had this spring. By a
similar process I ripened two large plants of Reticularia
maxima, which were brought to me in the early stage, of a
cream-coloured mucilage.t

I think it worth while to mention as a somewhat singular
circumstance, that on the same alder twigs upon which S.
Cryptosporti was produced, there occurred another Spheria,
the perithecium of which was so amalgamated as it were with
the perithecium, or stratum proliferum, of the Cryptosporium,
as to be hardly, if at all, distinguishable from it. The spo-
ridia of this latter Spheria were quite different from those
of S. Cryptosporit, being broadly elliptic and indistinctly
triseptate, I think occasionally quadri-septate. One of the
asci of this Spheria is represented at fig. 14.

There are several other fungi which have afforded me
materials for interesting observations, bearing upon the ques-
tions to which this paper relates. It would, however, take too
much time and space to discuss them now, but they may I
hope form the subject of a future communication.

* T had found Spheeria Cryptosporii on one previous occasion in the
course of last autumn. It was then unaccompanied by the Cryptosporium.
Tam unable to determine the wood upon which it occurred, having only
one small fracment.

+ These plants of Reticularia maxima took nearly three days to come
to perfection. The length of time was probably much greater than it
would have been in their natural state. eticularia atra passes through
all its phases in about eight or ten hours.

VOL, Ill. ay

274 BRANSON, ON CILIARY ACTION.

On Cittary Action as the cause of the CrrcutatTion in the
Cetus of Puanrs. By Fercuson Branson, M.D., Sheffield.

Tue cause of the circulation of the granules of chlorophyll
in the cells of certain plants has hitherto been involved in
mystery. I have spent many hours in examining the circula-
tion in the cells of the Anacharis alsinastrum, the new water-
weed ; and in October, 1854, I first observed a distinct ciliary
wave at the edge of the outermost cells. Repeated examina-
tions have satisfied me that the rotatory movements depend
upon cilia attached to the inner surface of the cell-wall. The
cilia are extremely minute, and require the highest powers of
the microscope, combined with very ‘“ happy” illumination,
to display their waving motion. The ciliary wave can only
be seen under very good daylight, or by means of the best
artificial illumination, In the Anacharis the cells best cal-
culated to display the ciliary wave are those at the edge of
the leaflet; for here a single layer of cells exists, and no
deception can occur from the movements in the cells beneath.
A leaflet should be selected in which the granules are just
beginning to move, or rather have not got into rapid motion ;
the ciliary movement is then less active, and, consequently,
can be more readily seen, The microscope must be very
accurately adjusted in order to define the wave, and even
then the observer’s patience may be severely tried before he
is rewarded with a sight so interesting and remarkable. A
cell in which a large number of granules are circulating
should not be selected for observation; the greater the number
of granules the more wil! the view be obstructed and confused.
I have used an eighth of an inch object-glass, by Powell and
Lealand, aided by their improved achromatic condenser, and
a No. 2 eye-piece. A power less than this will not define
the ciliary wave. The diaphragms used are numbered 4 and
5 on the condenser. A diaphragm with a central stop—ab-
solutely necessary for resolving the more difficult Navicula—
will not display the cilia, I am the more minute on this
point, for without great attention to the manipulation the
wave will not be seen. The cilia are extremely minute, pro-
bably not much larger than the dots on some of the Navicule,
and much more difficult to illuminate satisfactorily. It may
be said that cilia so minute could not draw to the side of the
cell, and then impel around it the large granules of chloro-
phyll which float within it. Let any one place a small
portion of cork or paper in the centre of a large basin of
water, and when the water is perfectly at rest gently agitate
it in one direction at the side of the basin, and the cork

BRANSON, ON CILIARY ACTION. 275

or paper will very soon be drawn to the edge. Now the
cork in this case bears about the same proportion to the basin
of water which the granule of chlorophyll does to the cell in
which it floats. In the latter case, however, instead of 2
single gentle wave at one point of the edge of the basin, we
have a wave surrounding the whole cell, formed by innu-
merable very minute cilia; and this multiplication of minute
forces produces a current of considerable velocity. Of course
the current once established becomes quicker and quicker,
and is helped onward by its own impetus, This exactly
explains the appearance presented on the first starting—so to
speak—of the circulation in a cell: a granule of chlorophyll
is slowly drawn to the edge of the cell, and then slowly moves
round it ; another granule follows, until all are at length
drawn to the edge, and pass round ; the motion then becomes
quicker and quicker, until it reaches the limit of its speed.
But the ciliary motion is occasionally irregular—slower in
some parts of the line, or perhaps interrupted altogether ;
and the consequence is, that the granules accumulate at the
weak, or interrupted point, until the re-established ciliary
Wave again urges them forward. Any one accustomed to
watch the circulation in plants must have frequently observed
that the granules of chlorophyll become crowded together, and
then slowly and singly again move onward. Ciliary action
satisfactorily explains this movement. In the cells of the
Anacharis the cilia are arranged in lines around the cell ;
occasionally, however, the granules of chlorophyll, instead
of passing round the cell, turn off at an abrupt angle, and
cross it; when this is the case a bright line may be observed
on the cell wall, and along this bright line the granules pass.
This line may be distinctly seen on the cell-wall before the
granules are in motion, and, if accurately examined, will even
then give an indication of a minute current passing along its
course. This bright line is doubtless the base of a line of
cilia, but the ciliary wave cannot, under these circumstances,
be seen, for the cilia are not in profile. The Anacharis is
better adapted to display the ciliary wave than the Valisneria.
In the latter it is difficult to slice off a single layer of cells,
whilst in the former Nature has prepared a single layer most
suitably arranged for observation. ‘The currents seen in the
hairs of certain plants differ somewhat from those in which
the granules of chlorophyll circulate ; they are more minute,
irregular, and weaker. Even whilst observing a hair of the
Groundsel currents start into view, which a moment before
were not in existence, and as rapidly pass away —others follow
a more definite course, and sometimes the whole hair appears

yp 2

276 BRANSON, ON CILIARY ACTION.

covered with a complete network of currents. I have ex-
amined many varieties of the hairs of plants, and few have
been the specimens in which—in some of the hairs at least—
indications of currents could not be detected ; so frequently,
indeed, have I found these currents, as to lead to the inference
that all the hairs of plants are furnished with an apparatus
adapted to the production of currents. Now this apparatus
is most probably identical with that which gives rise to the
circulation in the Anacharis, viz., minute cilia. I say most
probably, for the extreme minuteness of the currents render
the demonstration of cilia in many cases very difficult. In
one of the hairs from the leaf of a scarlet Pelargonium a
waving current was very evident. In the hairs of the common
Primrose a ciliary wave was detected at the edge of the cells ;
the waving current was particularly well seen in this instance,
as no granules were floating in the cell, which, when carried
along in the current, interfere much with the view of ciliary
action. The whole internal surface of the cells of some hairs
is probably lined with a minute waving pile. At least this
will account for the varied and irregular direction of the
currents. In one cell, in the hair of a Polyanthus, I watched
a flocculent line, or wave, passing diagonally along the whole
of the cell ; the current at the same time setting in the direc-
tion of the length of the wave. This is difficult to explain
without a diagram.

A, arrow indicating the course of the wave across the cell. B, arrow
indicating the direction of the current along which floating granules
were carried.

Currents are well seen, not only in the hairs, but also in
the cuticle of the leaf of the London Pride ; although the
ciliary wave is not well seen in this plant, in consequence of
the great number of minute granules which float in the cells.
The currents seen in the leaf-cells of the London Pride, and
also in the leaf-cells of the Primrose, are precisely similar to
those seen in their respective hairs; they are equally minute,
irregular, and weak. Although the current is very distinctly
seen, the motive force is not sufliciently powerful to move
any granules of chlorophyll which may happen to be in the
cell ; occasionally, however, a granule of chlorophyll may be
seen slowly moved by the current, just as the granules are

ee ee eee

WENHAM, ON THE CIRCULATION OF THE SAP, ETC. 277

moved in the Anacharis, showing that the force is the same
in both cases. Ina hair of the Primrose I watched an octo-
hedral crystal of oxalate of lime carried by the current several
times from end to end of the cell. By the term ciliary wave
it is not intended to imply that individual cilia can be seen.
All that can be shown is a waving motion, such as would
undoubtedly be attributed to ciliary action 1f seen in an
animal structure. I will not at present attempt to offer any
suggestion as to the use of these currents, though they must
play an important part in the vegetable cell. Observations
made with microscopes of high power and of recent construc-
tion are as yet too limited, Other observers will doubtless
be led to investigate the subject, and the accumulation of
additional facts may lead to a solution of this difficult pro-
blem.

OBSERVATIONS on the CrrcuLaTion of the Sap in the Lear
Cetts of ANnacuarts Atsrnastrum. By F. H. Wennam.

Tuere is no known plant in which the sap-rotation has been
discovered that displays the phenomena of the circulation
more distinctly, or in such variety of detail, as the newly
imported water-weed, Anacharis Alsinastrum. Having ob-
served some peculiar features in this, which I have not dis-
covered in the circulating sap of any other plant, I venture to
announce them. I must, however, premise that I have not
made a special study of this department of vegetable physio-
logy, and may therefore be excused from drawing any con-
clusions, or for showing a defective acquaintance with techni-
calities ;—I have simply to relate what I have seen.

Those who are not already familiar with the plant may
readily recognise it by its peculiar characteristics :—Its form
of growth is in long slender stems, which bear a series of
three narrow leaves, of a pale-green colour, at intervals of

Bigs ie

about a quarter of an inch asunder; these, when full grown,
seldom exceed a length of three-eighths of an inch (see fig. 1).

278 WENHAM, ON THE CIRCULATION OF THE SAP

The thickness of the leaf is composed of two layers of cells,
uregular both in form and position, as shown in fig. 2. The

Fig. 2

margin of the leaf consists of a single layer of cells of great
transparency ; it is in these that the remarkable phenomena
accompanying the circulatory movement are best seen. To
observe this satisfactorily a good eighth is necessary, having
an aperture of from 120° to 130°; if it extend beyond this
the object will be less perfectly shown, on account of the
close approximation of the front lens, and the difficulty of
adjusting for thickness of cover. For illumination I prefer
the achromatic condenser with a series of stops, and for con-
taining the object, a compressor having thin glass both over
and under the object. The best leaves for examination are
those which have slightly changed colour from age; the
young and vigorous specimens oftentimes displaying the cir-
culation but very feebly.

Upon first seeing the object under these conditions, it
appeared to me that there was something very remarkable in
the structure of the immediate surface of the walls of those
cells in which rotation could be seen: I immediately removed
the microscope into direct sunlight. As thus illuminated the
whole interior of the cell appeared to be lined with cilia, each
developed in a most distinct manner, and altogether exhibiting
the wavy undulating appearance usually caused by ciliary
motion. The movement of the green chlorophyll granules
also tended to favour this deception ; for by the action of the
supposed cilia they were occasionally collected together in a
mass at one end of the cell, and the particular manner in which
the preceding ones were again disentangled, one by one, at
the point of least resistance, seemed to be due to the mecha-
nical or sweeping power of the cilia.

If the existence of cilia in plants of this description could
be established, it would no doubt serve to explain many
obscure points in vegetable physiology ; but subsequent ob-
servation has shown me that the appearance of these in the

ie RT 4 2 te Ae

IN THE LEAF-CELLS OF ANACHARIS ALSINASTRUM. 279

Anacharis was a deception, caused by oblique sunlight, which
though favourable for discovering the existence of minute
markings is entirely unsuited for the purposes of truthful
investigation. ‘The mobile investment round the margin of
the cells has a well-defined boundary: in an instance where
the progressive circulation was very rapid I measured the
thickness of the layer, and found it not more than 1-25,000th
of an inch (in general it is rather more than this, or about
1-20,000th). Now if this should represent the extreme length
of each ciliary filament, in order to possess the requisite
elasticity and tenuity, the proportion of length to diameter
should be at least ten to one; this would at once place the
thickness of the filament beyond the limits of microscopic
vision, and clearly proves that if a series of cilia really existed
of these dimensions it would be impossible to see them. By
examining detached portions of the cell-walls with the largest
apertures and most careful illumination, I cannot discover any
rugose indications in its apparently uniform outline.

I have made numerous examinations of this marvellous and
beautiful object, under different circumstances and conditions,
and will now describe the facts I have observed relating to
its structure and vital functions. The thickness of the di-
vision between the cells is about 1-14,000th of an inch. In
certain stages of disease, or decay, this sometimes becomes
equally divided, showing that each cell has its own inde-
pendent membrane. No particular structure can be dis-
covered in the cell-wall: all the cells are filled with a thin
fluid, and contain a number of chlorophyll granules, varying
from three or four to upwards of fifty. The eranules very
much resemble those of the Valisneria, but are rather larger.
Their dimensions are from 1-3000th to 1-5000th of an inch.
They are somewhat irregular in shape, some being of an oval
form, and others a nearly circular, flattened disc. Each
spherule has a granulated appearance, arising from six or
eight separate nuclei; they are rendered more apparent by
a solution of ammonia, which also changes the green colour of
the granule to a yellowish tinge.

The chlorophyll granules are entirely dissolved by dilute
sulphuric acid. Treated with tincture of iodine they are
changed to a brown colour, with a nucleus of a darker shade,
and the apparent development of an external membranous
envelope.

When the rotation is active the greater number of the gra-
nules travel round the margin of the cells. A few remain
fixed in the centre, chiefly consisting of those whose form
approaches to that of a round flattened disc.

280 WENHAM, ON THE CIRCULATION OF THE SAP

The deportment of the granules during their passage has
already been described in the Microscopical Journal for Oct.
1853, page 54, by Mr. Lawson, to whom we are indebted for
the discovery of the sap-rotation in this interesting object.
When the rotation is moderately active, the speed of the
granules is about 1-40th of an inch per minute; a motion
apparently small until magnified to 800 linear, when each
eranule is seen to travel round its containing cell, with suf-
ficient rapidity, several times during one minute.

The rotation in one cell does not exert any influence upon
the direction of the granules travelling in the immediately
adjoining one. The motion is sometimes the same way, but
quite as often in the contrary direction.

The question now is, what is the agent that gives motion
to these otherwise inactive granules? I have before remarked
that the whole interior of each cell is lined with an investing
layer in rapid motion, of a thickness varying from 1-20,000th
to 1-25,000th of an inch. This stratum I have ascertained to
be entirely composed of a multitude of active corpuscules,
differing in size from 1-60,000th to 1-90,000th of an inch.
Iam not quite positive about their exact dimensions, for, on
account of their gelatinous nature, they do not possess a very
definite outline, and are, in consequence, somewhat difficult
of measurement. They are not, however, in general, much
larger than I have stated.

If one of the leaves of the Anacharis be placed on a piece
of thin glass, with a very small quantity of water, and then
torn into minute fragments with two needle-points, and
finally covered with neces piece of thin glass, on viewing the
fluid with an eighth object-glass, it will be seen that it is
entirely filled with these active corpuscules, exhibiting that
vigorous isochronal motion characteristic of molecular ac-
tion.

A weak solution of ammonia rather increases the activity
of these bodies, but dilute alcohol and acids immediately
destroy the movement.

These combined corpuscules are essentially the principle
of the vital movement in the plant, and also the vehicle that
causes the rotation of the chlorophyll granules, which are of
themselves perfectly passive, and move only in obedience to
the direction and control of the corpuscular current; neither
is the presence of the granules at all necessary for the excita-
tion of the active principle of circulation, for I have repeatedly
seen cells containing not a single gr ahlet in which the cireu-
lating layer was in a rapid Sate of progressive motion—in
fact, ‘the presence of numerous granules rather tends to retard

——————ee

IN THE LEAF-CELLS OF ANACHARIS ALSINASTRUM. 281

the cell current than otherwise. When a stoppage occurs,
the corpuscules of the circulating layer become piled against
the back om the last granule; in some instances almost to
overflowing ; but the disentanglement is generally effected by
the tr nee Taflncace of the moving investment releasing the
preceding granules in succession.

The chlorophyll granules do not appear to possess any
affinity for the active investment; they seem to be attached to
it only by simple adhesion. When a granule has been
impelled against an obstacle, it is sometimes thrown out from
the cell- wall, and, during the first instant of its rise, | have
seen it hee up a column, or thread, of the glutinous corpus-
cules. If the granule becomes quite detached, it will remain
stationary in its position, close to the investment, till it is
forced again into the line of march by the contact or motion
of succeeding ones.

The investment of active corpuscules is strongly attracted
by the cell-wall, and the progressive activity of the one
appears to be dependent upon the vital condition of the other.
If the continuity of a portion of the surface of the cell-wal! is
impaired, the active layer will not travel over the part thus
differing in substance. Fig. 3 represents one of the hollow
spines, or hairs, at the margin
ot the leaf; in these the granules
are sometimes seen in active mo-
tion. When they arrive near the
apex, where the cell-wall is in-
durated, shown by a brown dis-
coloration, indicating a loss of
vitality, they are invariably car-
ried across the circulating layer,
taking a short cut over, as at
in the figure. A few stray gra-
nules are sometimes thrown into
the dark-coloured hollow end of
the hair, but these are motionless.

Although there is undoubtedly
a principle of attraction existing
between the active investment
and the cell-wall, yet I am led
to conclude that there is nothing
peculiar in the structure of the
surface of the latter to determine
the direction of rotation of the
travelling current. When a plant of the Anacharis has
been kept in a cold, dark place for one or two days, usually

Fig. 3.

282 WENHAM, ON THE CIRCULATION OF THE SAP

not a symptom of circulation can be discovered: if a leaf
suitable for examination be now viewed under an eighth,
selecting the more transparent single thickness of cells at
the margin of the leaf, it will sometimes be found that the
layer of active corpuscules has collected, or run together,
on the cell-wall into one, or sometimes two heaps or mounds,
being in a torpid and quiescent state. After having care-
fully adjusted the object-glass, if the achromatic condenser be
focussed on one of these heaps, a bright sky being used for
the source of illumination, the slight degree of heat thus ob-
tained is sufficient to call into existence the dormant vitality
of the active corpuscules. At first, a few atoms on the
summit of the mound appear to be loosened, exhibiting their
peculiar tremulous motion; next, a few will start off and take
the lead, generally across the cell the movement of vibration
being apparently converted into one of direct progression ;
immediately, a single file of particles will follow in rapid
succession, in a wavering direction from side to side, much
resembling a torrent of ‘bubbles arising from a spherule, or
small aie at the bottom of a glass vessel of water, at the
commencement of ebullition. Sometimes another line of
particles will start off in a different quarter, and, as the heap
of corpuscules becomes more fluid and melts down, a very
singular commotion takes place; currents are seen traversing
the cell all ways, without apparent rule or order, and two are
sometimes seen travelling on the same side of the cell-wall in
opposite directions: at last, the united numbers and strength of
one current will gain the mastery, and determine the ultimate
direction of rotation, which will then go on steadily for hours,
the chlorophyll g examules being duly arranged, and performing
their traverse in proper form.

So far as I have ascertained, heat seems to be the best
excitant of the circulatory movement. It is slightly accelerated
by the transmission of an electric current ; but this effect may
also be due to the creation of a rise of temperature. The leaf
of the Anacharis is very sensitive to the application of
external reagents ; weak alcohol, ammonia, or acids, instantly
destroy the motion of the sap-current.

There is yet another collection of bodies found in all the
various forms of cell composing the leaf of the Anacharis ;*
they are oblong spicular-looking particles, of a light-brown
colour, having an average length of 1-11,000th of an inch;
they mostly congregate together in the most vacant part of
the cell, either at the centre or one end, and exhibit that brisk

* Seen also in the Valisnerta.

IN THE LEAF-CELLS OF ANACHARIS ALSINASTRUM. 283

vibratory motion peculiar to molecular action. This also
occurs when there is no symptom of rotation in the cells which
they occupy, and in instances where the rest of the cell con-
tents appears to be dead. They are quite independent of the
active investment, and are oftentimes so numerous as to be
tangled together in a mass, forming a kind of nucleus, which
is occasionally kept in rotation by the movement of the
chorophyll granules. Some cells are free from them, but
frequently it is difficult to find one in which they do not exist ;
they are not “parasitic,” but form one of the constituents of
the growth of the plant.

I have now recorded my observations on this remarkable
plant ; though I am still of opinion, from the variety of the
phenomena displayed, that a careful series of examinations
will bring fresh facts to light, and that the Anacharis
(although denounced as a ‘‘ pest”) may possibly prove to be
one of the keys for unravelling some of the mysteries of
primary vegetable organization. I have entered upon the
inquiry without learning what has been done by others in
this department of microscopical investigation, and therefore
refrain from expressing opinions or from drawing any con-
clusions from the result. I only offer it as a query, with
respect to the elementary principle of the circulation of the
sap in plants. May not their growth and vitality depend
upon what is known as ‘‘molecular action?” I make the
remark, because I have observed that the sap of many dif-
ferent vegetable species exhibits this peculiar motion; and I
would further inquire, whether the ciliary movement dis-
covered in several organisms, decidedly belonging to the
vegetable kingdom, may not also be a modification of mole-
cular action, and governed by the same exciting power?
For it appears to me that there are many points of analogy ;
and it is difficult to imagine that a single cilium, of perhaps
unicellular structure, and so minute as to be almost beyond
the limits of microscopic vision, should derive its vibrations
from an internal mechanism. Experiment tends to prove
that the acting stimulus of motion exists externally.

I have finally to remark that this is one of those com-
paratively-few subjects which requires the use of large
apertures, and the highest powers for its investigation (I
have found a twelfth extremely serviceable), combined with
considerable care in the illumination ; for many of the pheno-
mena are on so minute a scale as to be classed among very
difficult tests.

( 284 )

TRANSLATIONS.

On the CELLULOSE (in Animals) Question. By R. Vircnow.
Archiv. f. pathol. Anatomie, ti. Physiologie, &c., vol. viil.,

El p, 140:

Since my former communications respecting the substance
met with in the human body resembling vegetable cellulose,
I have taken much pains to ascertain more precisely its
nature. In now recurring to the subject, it is not that 1 have
been altogether successful in the inquiry, but rather because I
perceive that it is becoming more and more involved in con-
fusion. There are some even who, whether from superficiality
or for other reasons, appear to regard what I have said,—as I
believe with sufficient distinctness—as unsaid, and have
busied themselves in associating with the amyloid bodies
described by me, bodies of all kinds, only morphologically
analogous with them. The reaction of iodine and sulphuric
acid having once been established, nothing can be described as a
corpus amylaceum which does not exhibit this reaction. At
most can such bodies be termed corpora amylacea spuria.

To this class of false amyloid bodies, which have been
explained as true, belong—

1. The brain-sand, noticed by Cohn (Bericht, tiber das
Allerheiligen-Hospital zu Breslau, 1854, p. 14). Except
that Busk (Quart. Jour. Mic. Sc., 1854, January, No, 6), in
one instance, under particular circumstances, found in the
corpus striatum calcareous bodies, whose external soft layer
assumed a peculiar reddish-yellow colour under iodine alone,
which induced him to compare it with the immature cellulose
of many plants, as of Hydrodictyon.

2. Various gelatinous granules, which have of late been fre-
quently comprehended under the ambiguous name of “ colloid
granules.” Many of these are decidedly of an albuminous
nature, as I have said before (vol. vi., p. 580). It is possible
that the bodies described by Gunsberg (Zeitsch. f. Klin.
Med., v., p. 297) from a colloid tumour of the abdomen
belong to this class, although the description is not suffi-
ciently clear ; and in a cerebral tumour occurring at the same
time, arenaceous corpuscles are described as of an amyloid
nature.

3. The concentric epidermis globules (globes épidermiques),
which are met with most abundantly in cancroid tumours,

VIRCHOW, ON THE CELLULOSE QUESTION. 285

and which Gunsberg places with the corpora amylacea. To
this category also belong, as I first stated (Arch., vol. 1i1.,
p. 222), the concentric bodies of the thymus-gland, of which
Funke (Wagner’s Physiol., 4th ed., 1854, p. 127), supposes
that they are identical with the corpora amylacea of the
brain. J have expressly stated (vol. vi. p. 138), that they
do not exhibit the peculiar reaction with iodine and sulphuric
acid, ‘The same may be said of the so-termed colloid bodies
of the hypophysis cerebri.

4. The so-termed Hassallian corpuscles in coagulated
blood, but which should properly be named after Gulliver,
since they had previously been described and figured by him
in his translation of Gerber.

5. The medullary matter described by me (vol. vi., p. 562),
and identified by Henle with the Hassallian corpuscles, not-
withstanding that its analogy with the nerve-medulla had not
escaped his notice, and which is placed by Meckel under his
*‘lardaceous substance” (Speckstoff), although it is a normal
constituent of most tissues. I had already stated that this
substance does not exhibit the peculiar reaction with iodine
and sulphuric acid, that it is soluble in hot alcohol, in ether,
and other substances, in which the corpora amylacea are in-
soluble, and also that it resists concentrated acids and
alkalies, which at once destroy the corpora amylacea. In
short, this medullary matter (Markstoff) has nothing in com-
mon with the corpora amylacea.

6. Leucin-granules, which are so readily separated par-
ticularly in extract of milk, and which have also been de-
scribed by Meckel as a kind of fat, and placed under the
lardaceous substances. ‘These bodies also, do not exhibit the
reaction with iodine and sulphuric acid.

Among all animal substances there is but one, so far as
our present knowledge extends, which can be brought into
question, and this is cholesterin. The great difference
which exists between cholesterin and the corpora amylacea,
I have already (vol. vi, p. 420) pointed out in a cursory
manner. It will be sufficient, here, to remark that the cellu-
lose-like or amyloid substance, whenever it is met with, exhibits
changes under iodine alone without any addition; thus the
corpora amylacea of the nerve substance exhibit a bluish,
and those of the spleen, liver, and kidney, a yellowish-red
colour. Were this not the case, it would have been quite
inconceivable how Donders and Busk should ever have
thought of such a thing, as-at once to declare them to be of
the nature of starch. No sort of cholesterin upon the simple
application of iodine presents any change of the kind, and

286 VIRCHOW, ON THE CELLULOSE QUESTION.

o

still less is it witnessed in situations where cholesterin in the
combined state exists abundantly; as, for instance, in the
nerves and in the spleen, of which I have shown that when it
has not undergone the amyloid change, still it contains a very
large amount of cholesterin (vol. vi, pp. 425, 565). On the
other hand I would again remark, that sulphuric acid by itself
changes cholesterin-crystals into brown or brownish-red drops
(vol. vi., p. 420, vid.; also Wiirzb. Verh., B. 1, p. 314),
whilst the corpora amylacea are destroyed without any change
of colour.

Busk, in his researches, besides iodine with sulphuric acid,
also employed Schultze’s reagent,—chloride of zinc and iodine,
—and obtained also by its means the blue reaction. I can
confirm this as regards the brain, as well as with respect to
the waxy degeneration of the spleen, liver, and kidney. This
reagent even is to be preferred, from its greater convenience
of application, to the iodo-sulphuric acid, only it must be very
carefully prepared. At first I had hoped that it would afford
a new test by which to distinguish cholesterin, but it was soon
apparent that it also induced the most beautiful blue colour
with that substance, although very slowly. At the same time
I perceive, with much astonishment, that in England many
conceive that the amylaceous nature of the bodies is proved
by this reaction, This is altogether erroneous, for it is pre-
cisely this which is to be regarded as especially characteristic
of cellulose.

In the impossibility of completely isolating the substance
in question, | have repeatedly sought to produce its charac-
teristic decompositions. My endeavour to change it into
sugar, by means of sulphuric acid failed (vol. vi., p. 426). I
then experimented with saliva, and of course with saliva
which was proved to be capable of readily decomposing vege-
table starch. But these experiments also afforded no satis-
factory result, either with normal saliva or with the secretion
of a person under mercurial salivation, which possessed very
energetic decomposing properties. Another series of experi-
ments appeared to afford more favourable results; but 1 was
unable to arrive at any definite conclusion, owing to the cir-
cumstance that, latterly, fresh materials were wanting. In any
case the question remains in this state, viz.:—that of all
known substances none appears to be so closely allied to these
bodies as are starch and cellulose.

In respect to the situation in which the degeneration may
be demonstrated with certainty, they are as follows :—

1. The nervous system. Besides the situation before noticed
may be mentioned the ligamentum spirale cochlee (Wurzb. Ver-

VIRCHOW, ON THE CELLULOSE QUESTION. 287

hand., Bd. V., p. 18), and numerous points in the atrophied
substance of the brain and spinal cord. I have myself re-
peatedly found them in astonishing quantity in the gelatinous
and cellular softening of the brain, and particularly of the spinal
cord. Busk found them, in one case, throughout nearly the
whole brain. Willigk (Prager Vierteljahrsch. 1854, Bd. IV.,
p. 93) discovered them in cicatriform spots in the brain; and
Rokitansky (Sitz, Ber. der Wiener Akad, 1854, Mai. Bad.
XIII, p. 122), in various parts in a state of atrophy, particu-
larly in the brain. Like Busk I have also seen them in the
choroid plexus, although I am not quite sure whether they
may not have been accidentally introduced.

2. The spleen. In this organ the change exists both in the
cells of the follicles and of the pulp. The arteries, as has
been stated before by Meckel, exhibit the degeneration in
their thickened walls throughout all the coats, and, in par-
ticular, there is no doubt that the annular fibrous coat also par-
ticipates init. Sanders (Monthly Journal, 1854, Nov., p. 468)
rightly remarks that the trabecule likewise are changed ;
I have seen them thickened and rendered blue throughout by
the action of reagents, If the deposit is not quite pure, the
colour is more of a violet tint, or perhaps of green or greenish
blue.

3. The liver. In the true waxy degeneration it is chiefly
the hepatic cells which undergo the change, although it some-
times happens that the interstitial connective tissue as well is
implicated in it.

4. The kidneys. In these organs the amyloid condition is
of the most frequent occurrence. The change commencing
most usually in the Malpighian coils and in the afferent arteries,
which are enormously thickened and have their walls infiltrated
throughout. Next to these the connective tissue, surrounding
the papillary tubuli urinifert, is chiefly affected; far more
rarely the portions seated higher up.

Further investigations will show whether a simple infiltra-
tion exists in these cases, or a direct degeneration. The case
related by Stratford (Quarterly Journal Mic. Sci., 1854,
p- 168) of an epileptic patient, in whom corpora amylacea are
said to have existed in the blood, is not so certain that the
matter can be regarded as decided by it. In any case, in
most organs we have to do with an indubitable change in the
structural elements; and should my original view be farther
confirmed, this change might briefly be described as a ligni-
fication of them.

It is of especial interest to consider the finer varieties of
this substance in connexion with the corresponding vegetable

288 VIRCHOW, ON THE CELLULOSE QUESTION.

matters. The corpora amylacea of the nervous centres, both
morphologically and chemically, approach the nearest to the
amylox-granules of plants. They have the same concentrically-
striated structure, the comparatively strongly-reflecting sur-
face, the bluish colour, upon the simple application of iodine,
and lastly, their swelling in hot, and their ultimate solution,
although with chemical change, in boiling water. Busk even
says, what Donders and myself have been unable to perceive,
that some of the smaller corpora amylacea exhibit, in polarized
light, a sharply-defined dark cross, the lines forming which
decussate in the centre of the granule at an angle of 45°,
though it must be allowed that most of them exhibit only a
single dark line. The same observer also believes that in
one case he perceived minute particles of the amyloid sub-
stance enclosed in cells, whose cavity they only partly oc-
cupied.,

Widely different from the above is the amyloid degeneration
of the vessels, of the connective tissue, and of the cells in the
spleen, liver and kidney. In these situations I have never
obtained a blue, nor even a bluish colour, by the addition of
iodine alone; on the contrary, the peculiar yellowish-red is
exhibited, which has from the first surprised me (vol. vi.,
p- 269), and which Meckel has since described as “ iodine-
red,” and proposed as a characteristic of his lardaceous sub-
stance. But at the same time care must be taken with respect to
this, since, especially all parts containing blood, often assume a
very similar appearance. At present it appears to me that
we are in no case justified in admitting the existence of
an amyloid substance, where a vioclet-blue or bluish-green
colour is not produced upon the subsequent addition of sul-
phuric acid or of chloride of zinc. But in all such cases it is
advisable by the simple addition of concentrated sulphuric
acid, to satisfy oneself that similar colours are not produced
by that reagent, as may very well be the case, especially in a
series of animal colouring matters.

Whether the yellowish-red, or iodine-red appearance of the
parts indicate any specific substance, is still to be shown.
Busk seems inclined to compare with it a kind of immature
cellulose, such as is said to occur in the lower plants. In any
case, however, the deposition of the substance presents a close
resemblance to true lignification—the formation of cellulose
in plants. But in the vegetable kingdom, as is well known,
the most numerous combinations of cellulose with nitrogenous
substances are met with, so that, as Mulder in particular has
shown, on the addition of iodine with sulphuric acid all sorts
of impure colours are presented, constituted of a mixture of

ON A SOLUTION OF UREA UPON THE BLOOD-CELLS. 289

blue and red, or of brown and yellow. A similar play of
colour may be witnessed particularly in the spleen, and espe-
cially in the amyloid procured from the pulp and from the
follicles, whilst nowhere do the blue and bluish-red colours at
once appear so distinctly as in the Malpighian coils and the
afferent arteries of the renal parenchyma, It appears, there-
fore, scarcely to admit of a doubt, that sometimes sooner, some-
times later, the albuminous substance of the tissue disappears
and is replaced by the amyloid.

In those cases, in which the substance differs still more
widely from starch, and more close approaches cellulose, the
organs affected exhibit the peculiarly pale, transparent, reddish
or yellowish, or even brownish aspect, together with the cha-
racteristic, as it were, oedematous consistence, which, as I
conceive (vol. vi., p. 426), should be described as ‘ waxy,”
and not as lardaceous. I see with pleasure that the same
idea, independently of me, has been adopted in Edinburgh,
and the process been at once described as “¢ waxy degeneration”
(Monthly Journal, 1854, February and March). In the
majority of cases the indurated organs are at the same time
enlarged, so that no doubt can be entertained that new matter
must have been taken up.

The coexistence of amyloid disease in the liver, spleen,
and kidneys, which has been so often observed, though not
so frequently as many believe, of course leads to the suppo-
sition of the existence of a common cause—of a constitutional
disturbance. A humoral pathologist would naturally suppose
a corresponding crasis. But a more cautious observer would
be satisfied with saying, as I have done in my former com-
munication on the subject of the “ waxy spleen,” that the
common factor is a cachectic condition, whose more special
nature remains to be elucidated.

On the Action of a ConcenTRATED Sovution of UREA upon
the Broop-Cetis. By A. KOLiIKER. (Zeitsch. f. Wiss.
Zool., vol. vii., p. 183.)

In the prosecution of a series of researches, respecting the
influence of various reagents upon the spermatic filaments,
I have almost always employed the blood-cells as a test of
the degree of concentration of the fluids experimented with.
I was thus led to observe, in the Frog, a remarkable change
produced in the blood-cells by a concentrated solution of
urea (30 per cent.). The blood-cells gradually acquired an
irregular, jagged outline, and were rapidly transformed into the
VOL. III. U

290 ON A SOLUTION OF UREA UPON THE BLOOD-CELLS.

most beautiful stellate cells, usually having 3—6 tolerably
long and somewhat clavate processes, so as to be brought to
resemble very closely the irregularly-stellate pigment-cells of
the lamina fusca of the sclerotic. This elegant form, however,
was not long retained ; for the processes now began speedily
to become melted dont sometimes disappearing by a gradual
process of fusion commencing at the border of the cell, and
occasionally in detaching larger or smaller droplets, when
immediately became pale ail disappeared. Thus, at last,
the nuclear part of the cell only remained as a minute, round,
dark-red, brilliant globule, which, ultimately, also lost its
colour and disappeared up to the nacleus without leaving a
trace.

In order to ascertain the causes of these extraordinary
changes in the bleod-cells, 1 began now to try the effect of
weaker solutions of urea. ‘These experiments showed, that
solutions containing 15 per cent. produced the same changes
as those above described, and this was the case also, though
more slowly, with solutions containing 12 per cent., or having a
specific gravity of about 1-043. In solutions of 1-026 sp. gr.,
the cells remained almost without change, whilst in others still
more diluted, down to a sp. gr. of 1:004, they were ren-
dered spherical and pale, with distinctly-visible nuclei, just as
they appear upon the first addition of water. These pheno-
mena, as well as the considerations which are opposed to the
assumption of a chemical influence being exercised by an
indifferent substance, such as urea, upon the blood-corpuscles,
induced me to try the effect of other concentrated solutions
upon the blood-cells of the Frog, whence it appeared that in
solutions containing 30 per cent. of “‘sugar of milk,” nume-
rous blood-cells were rendered so pale, that nothing remained
visible except the nuclei. The same thing takes place in all
the cells in a concentrated solution of glycerin, except, that in
this instance, many of the nuclez exhibit a very delicate border
due to the cell membrane. A similar effect follows the ap-
plication of mucilage of quince seeds. But in none of these
solutions did the blood-cells assume the stellate form, nor
exhibit the extraordinary fusion, and breaking up into sphe-
rical drops, which is manifested in solutions of urea; upon
which, however, the less stress, perhaps, should be placed,
since human blood-cells, in a solution of urea containing 30 per
cent. simply diminish in size, become rounded and lose their
colour, without previously exhibiting any other phenomenon.
Of salts I have hitherto only tried solutions of common salt
and of acetate of soda (Na O A). When concentrated solu-
tions of these salts are mixed with frog’s blood, and the

ON LYMPH-CORPUSCLES IN THE LYMPHATIC VESSELS. 291

mixture is left to itself for a few minutes, most of the cor-
puscles lose their colour entirely, scarcely anything remaining
visible except the nuclei. If the changes are followed more
closely, the corpuscles will be seen at first to become wrinkled,
in which condition also many remain for a long time ; but this
is succeeded by a stage, in which they become smaller and
rounded, and perhaps also throw out a few rounded protru-
sions, until at last they are rendered quite pale. On the
prolonged action of common salt, the corpuscles may often be
seen surrounded with a complete cloud of liberated particles
of hematin, and it would even seem that the cells frequently
disappear altogether under the energetic influence of the con-
centrated solution.

From the above it is allowable to regard the whole pheno-
menon as one of a physical nature, and to assume that, as
dilute solutions remove the colour of the blood-corpuscles by
endosmosis, so do concentrated solutions produce the same
effect by causing an excessive exosmotic current from the
blood-cells into the surrounding fluid. The very energetic
action of wrea, may perhaps be explained by the high value
of the endosmotic equivalent of that substance, with respect
to which I hope at some future time to be able to communi-
cate more precise observations.

Notice respecting the OccurRENCE of Lymen-Corpusctes in the

commencements of the Lympuatic VessEts. By A. KOLtriKeEr.
(Zeitsch. f. Wiss. Zool., vol. vii., p. 182.)

THE recent researches of Virchow on the one hand, and of
Briicke, Donders, and myself on the other, have shown that
the lymphatic glands are the principal seat of origin of the
cellaform elements of the chyle. The further question arises,
as to whether lymph-cells are formed in other situations
besides those organs, and particularly, whether the inde-
pendent formation of such cells, in the commencement of the
lacteals, which has recently been almost universally assumed,
be really deducible from well-ascertained facts. This question
is of the greater interest, that the formation of lymph-cells in
the commencement of lymphatics has hitherto been regarded
as one of the most certain instances of the formation of cells
around isolated nuclet contained in a fluid, whilst the more
recent results of histological inquiries have tended more and
more to limit the occurrence of a free cell-formation inde-
pendent of pre-existing cells. Consideration of the foregoing
facts, would certainly, at first sight, appear to render the
u 2

292 ON LYMPH-CORPUSCLES IN THE LYMPHATIC VESSELS.

question now. in discussion superfluous, inasmuch as it has
long been proved that the lacteals of the small intestine, even
at their commencement between the intestine and the mesen-
teric glands, contain lymph-corpuscles ; but here the possi-
bility arises, that the cells may be derived from the Peyerian
and solitary follicles, whose connexion with the lacteals is
asserted by Briicke, and which on this account have been
regarded as a kind of lymphatic glands. In this state of
things, it is above all necessary to investigate the conditions
under which, and the situations in which, the lymphatics
contain cellzform elements previously to their reaching the
lymphatic glands, and where not; an investigation which,
when carried out sufficiently, is more difficult than it appears
at first sight. Although I have had neither opportunity nor
leisure of instituting detailed researches on this subject, still
I am in a condition to communicate some facts, which may
serve as an introduction to further inquiries.

In a large Dog, which had been copiously fed a few hours
before death, and in which all the lymphatics of the abdo-
minal organs were distended, H. Miiller and I found, in all
the lacteals proceeding from the Peyerian glands, (which in
such cases are always enlarged,) in every preparation, a con-
siderable amount of colourless cells. The chyle from the
other vessels of the small intestine, however, also contained
cells, but these were in general less abundant, though in one
case likewise the number was not inconsiderable. In the
same way also the lymphatics arising from the large intestine
contained a certain number of cells in the pale-coloured
lymph. On the other hand, we were unable to discover a
trace of cellwform elements in the lymph taken from the
much-distended vessels of the liver.

Upon the supposition, therefore, that the solitary follicles
of the small and large intestine communicate with lymphatic
vessels, these facts would appear to correspond with the
hypothesis, that the lymphatic glands and the analogous
follicles of the intestines are the only sites of formation of
the lymph-cells.

On the other hand, again, I invariably found in the large
lymphatics of the spermatic cord of the Bull, close to the
epididymis, in several very carefully-examined cases, a certain,
though it is true but small, number of cells, which were in-
distinguishable from lymph-corpuscles.

Further investigation, for which I would recommend the
lymphatic vessels on the exterior of the gastric mucous mem-
brane of the Pig, and those of the uterus and liver in the
large mammalia, will show in what cases lymph-cells exist

INFLUENCE OF ALKALIES ON SPERMATIC FILAMENTS. 293

in lymphatics, which have no connexion of any kind with
glandular organs. Should it thus appear, of which I can
scarcely doubt, that the occurrence of these corpuscles, ob-
served by me in the lymphatics of the testis, is a frequent
event, the origin of these lymph-cells will have to be traced
further, and above all, it will be requisite to consider whether,
perhaps, the epithelial cells of the smaller lymphatics may
not participate in this cell-formation more than we have
hitherto been inclined to believe.

On the InrLuENcE of Caustic AtKaLies upon the Motions of
the Srermatic Firaments. By A. Ko6tumer. (Siebold
and Kollik. Zeitsch. f. w. Zool., vol. vii., p: 181, March 26,
1855.)

SETrING out with the well-known observation of Virchow
(Virch. Archiy., vol. vi. p. 133, 1853; Quart. Journ. Mic.
Sci., vol. ii., p. 108), with respect to the action of caustic
potass and soda on the cilia, | have in the last winter inves-
tigated their action upon the spermatic filaments. To my
agreeable surprise a perfect correspondence was exhibited
between these two motile bodies, except that I noticed an
influence from ammonia upon the spermatic filaments, which
had not been observed by Virchow in the cilia. In order to
observe the action of caustic alkalies upon the spermatic
filaments, the best mode of proceeding is to allow them to
become perfectly quiescent in a dilute solution of sugar or of
albumen, and afterwards to introduce the caustic in small
quantity beneath the covering glass. It will then be seen
wherever the potass or soda reaches that the mass is again
put into the most lively motion, fully as active as that of
the perfectly-fresh spermatozoids; but after a short time
(4—1—2 minutes) a total quiescence takes place, from which
the spermatic filaments cannot in any way be again roused.
This phenomenon is best witnessed on the application of a
solution containing from 1 to 5 parts in 100 of caustic soda
or potass. In stronger solutions it undoubtedly takes place,
but in this case the movement is soon over, nor does it occur
in all the filaments, many of which, and especially those which
first come into contact with the stream, exhibit, instead of
active vibratile and locomotive movements, only a few rota-
tions on the axis, and then become quiescent in the extended
posture. Concentrated solutions of caustic alkalies, contain-
ing from 10 to 50 in 100, also produce the phenomena of
revivification in a mass of quiescent spermatic filaments, and

294 ON THE RESTORATION OF THE MOTIONS OF

in a well-marked manner, but in this case care is still more
requisite than with more dilute solutions.

The above phenomenon is witnessed not only in the Mam-
malia in whieh I first observed it, but also in the Amphibia,
except that in the latter (Frog) far more dilute solutions of
caustic alkalies are required to produce it, the spermatic fila-
ments of these animals being much more readily destroyed
than those of the Mammalia. As respects the Birds and
Fishes, my observations in these classes are not concluded.

When the action of caustic alkalies upon the spermatic
filaments is observed farther, it is obvious that they are
powerful excitants, not only in concentrated solutions, but
that they also exert an influence in dilute solutions also. Imfa
solution of sugar, which does not affect the movements of the
spermatic filaments, be mixed with a small quantity of caustic
potass, so as to make a solution containing 1-1000 to 1-5000
of the alkali, it will be seen that a fluid of this kind not
only maintains the motions of the filaments for hours together,
but that it renders them even more lively than in the pure
syrup itself, so that it would seem as if very weak alkaline
fluids of a certain strength are the most favourable to the
movement of the spermatic filaments.

On the RESTORATION of the Motions of the SPERMATOZOIDS
of the MAMMALIA. By MM. MoLescuott and J. C.
RICCHETTI. (Comptes rendus, No. 13, Mars 26, 1855.)

THE author’s researches were made on the spermatozoids of
the Bull, taken m each experiment from the epididymis.
These spermatozoids have a lynx-shaped head, the depression
in which is small and situated towards the inferior third, and
a very long tail, furnished with a minute appendicular
nodosity, which is soluble in the alkalies, and is usually
placed in the middle of the filament, though in some indivi-
duals it is situated nearer to the head.

When the ¢estes have been procured from an animal recently
killed, the vitreous humour, diluted with three parts of water
and filtered, is very appropriate for the observation of the
movements of the spermatozoids ; but this fluid is no longer
sufficient when the testes have been kept for one or several
days. In order, then, to revive the spermatozoids, we are
acquainted with nothing which succeeds better than solutions
of common carbonate or phosphate of soda, containing 5-100th
of the salt. By this means, even after the lapse of two days,
all the characteristic movements of the spermatozoids may

THE SPERMATOZOIDS OF THE MAMMALIA. 295

be excited. At first, only a few exhibit trembling vibrations,
but which are soon communicated to others, and in two or
three minutes the whole are in motion as actively as in the
recent secretion. We have several times succeeded in re-
animating these motions of the spermatozoids, in the secretion
which had been retained in the epididymis three or four days
after the death of the animal, at a temperature varying from
5° to 20° Cent. If, instead of solutions of the above strength,
more concentrated ones are employed, the action is commonly
slower, weaker, and, above all, less general ; nevertheless we
have occasionally seen movements produced quite as rapid,
and also quite as general by means of a solution, containing
1-10th of the salt ; a solution containing 1-100th of the salt is
usually inert.

Chloride of sodium, is less efficient than the phosphate or
the carbonate of soda, inasmuch as its action is only very
feeble beyond 48 hours after the death of the animal. But
it is extremely remarkable, that a solution containing not
more than 1-100th of common salt produces the greatest
effect, whilst solutions containing 5, 10, and 26-4 per cent.
have none at all, and even solutions of 3 to 4 per cent. are far
less active than those with 1 per cent. The latter surpasses
in efficiency the solution of sulphate of soda, which, like the
carbonate and phosphate, ought to be of the strength of
5-100th. Solutions containing 1 to 10 parts of the sulphate
in 100 have a feeble action, and the concentrated solution
produces none at all. Ordinarily the solution of sulphate of
soda, containing 5 parts in 100, is less certain in its effects
and less active and durable than the carbonate, phosphate, and
chloride, particularly if the secretion is not recent.

As for the salts of potass, we have compared the carbonate
in a solution containing 5 in 100, and the chloride in one con-
taining 1 in 100. Their action is less constant, slower, less
lively and less general than that of the salts of soda.

What has been said of the semen of the Bull does not apply
to that of the Frog (Rana esculenta). According to our obsery-
ations, common salt retards the movements of the spermato-
zoid of the latter animal; the phosphate and the carbonate
cause them to cease altogether. ‘The spermatozoid of the Frog
coil up in solutions of the same salts, and at the same degree
of concentration, as revive those of the Bull with the greatest
energy. This difference recalls a fact observed by M. Moles-
chott, that the blood-corpuscles of birds (Fowls, Pigeons) are
less corrugated under the action of saline solutions than are
those of the Mammalia and of the Frog.

296 ON THE VITALITY AND DEVELOPMENT OF

On the Viratrty and DrEveLopmMent of the Spermatic Fiva-
MENTs. By A. Kotuiker. (From the Verhand. d. phys.
med. Gesellsch. in Wurzb. Bd. VI., 1855.)

REFERRING to a former communication (vide p. 293), con-
taining the observation, that caustic alkalies are powerful
excitants of the spermatic filaments, the author believes that
he has now arrived at certain results, of which the present
paper gives a preliminary account, the more detailed
exposition of his inquiries being reserved for a future
occasion.

The results which he has obtained, with respect to the
motile phenomena of the spermatic filaments, are embraced
in the following propositions, which have reference to the
Mammalia.

1. In pure semen, taken from the epidermis and vas deferens, motile
spermatic filaments exist in very great abundance.

2. In water and aqueous solutions of all innocuous, indifferent substances
and salts, the motion of the filaments ceases, and they form loops.

3. These filaments, thus furnished with loops, are not dead, as has
hitherto been generally believed; for, on the contrary, they revive com-
pletely upon the subsequent addition of concentrated solutions of innocuous,
indifferent substances (sugar, albumen, urea), and of salts.

4. In all animal fluids, when considerably concentrated, or highly
saline, which are not too acid nor too alkaline, nor too viscid, the motions
of the spermatic filaments are unimpaired ; this is the case, for instance,
in blood, lymph, alkaline or neutral urine, alkaline milk, thin mucus,
thick bile, the vitreous humour,—but not in saliva, acid, or strongly-
ammoniacal urine, acid milk or mucus, the gastric juice, thin bile, and
thick mucus. When the proper degree of concentration of the latter fluids
is successfully attained, and their reaction is rendered neutral, they are
innocuous.

5. In all solutions of indifferent organic substances moderately concen-
trated the filaments move with perfect facility—thus in all kinds of syrup,
in albumen, urea, glycerin, salicin, amygdalin. More concentrated solu-
tions of these substances cause the motion to cease, but it is restored upon
their subsequent dilution with water. Too dilute solutions act in the
same way as water (vide 2 and 3).

6. Certain solutions, as they are termed, of indifferent organic substances
act like water, however much they may be concentrated, such as solutions
of gum arabic, vegetable mucus (gum tragacanth, mucilage of quince-
seeds), and of dextrin. Concentrated solutions of other substances, in
this case also, restore the motions.

7. Many organic substances cause the motions of the filaments to cease,
owing to their chemical action upon them, such as alcohol, creosote,
tannin, and ether; others owing to their mechanical effects, as most oils.
Narcotics, in certain degrees of concentration, are not injurious.

8. Metallic salts are injurious, even in extremely dilute solutions ; such,
for instance, as a solution containing jh) of corrosive sublimate.

9. Most of the alkaline and earthy salts are innocuous in certain degrees
of concentration, which in some is greater and in some less; so little
hurtful, in fact, are they, that the filaments may be kept alive in them for

THE SPERMATIC FILAMENTS. 297

from one to four hours. Among these may be enumerated solutions of—
common salt; chloride of potassium; sal ammoniac; nitrate of soda ;
nitrate of potass, containing 1 part to 100: moreover, solutions containing
from 5 to 10 parts in 100 of phosphate of soda; sulphate of soda ; sulphate
of magnesia ; chloride of barium. As regards some of these salts, the fact
had been previously noticed by older writers, and more recently by
Quatrefages, Newport, and Ankermann. Solutions unduly diluted have
the same effect as water, and cause the formation of loops, but the filaments
are revived upon the addition of a concentrated solution of the same salts
and of indifferent substances (sugar, urea, &c.). Stronger saline solutions
than are required, also interfere with the motions; but, in this case like-
wise, the filaments are capable of revival upon the addition of water.
These salts can scarcely be regarded properly as revivifiers, as was asserted
not long since by Moleschott and Ricchetti (vide p. 294), for filaments
which have become quiescent in indifferent substances, as sugar, for
instance, are not revivified again by them; and their action is widely
different from that of the real excitants—the caustic alkalies. It cannot
be denied that their influence is very favourable, and that (but perhaps
owing only to their rapid diffusion in the water) they produce motion in a
seminal mass more rapidly than other less diffusible substances, such as
sugar and albumen; on which account the above-named authors ascribe
revivifying properties to them —a fact which, before them, had been made
known, as regards common salt, by Quatrefages, and by Newport, for
carbonate of soda and potass ; which latter salts, moreover, in my experi-
ments, caused the motion to cease in 10' or 15’, almost like the caustic
alkalies,

10. Acids, even in very small quantity, are injurious; such as hydro-
chloric acid, in the proportion of z45.

11. Caustic alkalies (soda, potass, and ammonia, not lime and barytes),
in all degrees of concentration, from j, to ~ are special excitunts of the
spermatic filaments. Whether the latter have become quiescent spon-
taneously, as in old semen, or have ceased to move in indifferent solutions,
the above substances recall the most active movements which are not dis-
tinguishable from the vital. But these motions cease after two or three
minutes, and from this quiescence the filaments cannot be roused by any
means. When mixed with indifferent substances in small proportions
(from 45 to ;\;), as, for instance, in syrup, the caustic alkalies afford
a means by which the motions of the spermatic filaments may be main-
tained for a long time.

12. Semen dried in indifferent substances, and in saline solutions, may,
in certain cases, have its motion restored by dilution with the same fluid,
or with water.

So much, as regards the Mammalia, with which, so far as
the author has had an opportunity of observing, the Birds
correspond in all essential particulars. In the Amphibia,
as, for instance, in the Frog, a difference was so far observable
that the spermatic filaments, owing to their chemical consti-
tution, required less concentrated solutions, in order to exhibit
their natural motion On this account water and aqueous
solutions have very slightly-deleterious effects on them ; and
greater dilution is requisite in the saline solutions, in order
to exhibit the movements, than in the Mammalia. That is
to say, one-half per cent. solutions of common salt ; chloride

298 ON THE VITALITY AND DEVELOPMENT OF

of potassium; chloride of ammonium; nitrate of potass; nitrate
of soda; carbonate of soda; and solutions containing ;},th of
phosphate of soda; sulphate of soda; sulphate of magnesia ;
muriate of lime; muriate of barytes, &c. All the other con-
ditions are alike: thus, in particular, the revivification from
concentrated saHne solutions, except that the alkalies act as
excitants only in very weak solutions, and are destructive in
stronger.

The spermatic filaments of Fish, in their behaviour towards
water, correspond more with those of the Amphibia, but they
are by no means so long-lived. They are distinguished also from
those of the Amphibia, and of all other vertebrate animals,
by the greater delicacy of their structure, and by the difficulty
which exists in the finding of media favourable to their motion.
In general the same degree of concentration in the solutions
should be employed with them as with the spermatic filaments
of the Frog, except that it seems there are but few substances,
such as phosphate of soda in the proportion of 1 per cent.,
and of sulphate of magnesia of the same strength, which are
altogether favourable to them ; but in these media I have seen
them in active motion for from six to twelve hours ; and such
solutions are perhaps adapted for the prolonged maintenance
in an active state of the seminal fluid of Fish. The revivifi-
cation after the action of water and of too concentrated solutions
takes place in them in the same way as in the spermatic filaments
of the Mammalia. The caustic alkalies also act upon them as
excitants, though only in dilute solutions of 4 to + per cent.,
for in stronger the filaments are immediately destroyed.

When these facts are carefully considered, it is obvious
that it is impossible, with Ankermann, to regard the motions -
of the spermatic filaments as the effect simply of endosmosis.
I consider that they are induced by molecular changes in
the interior of the filaments, which, though unknown, may
at present be compared with those in the muscular fibres,
and still more aptly to the ciliary organs of the Infusoria,
and to cilia in general, Should any one be inclined to the
opinion, that the revivification of filaments which have been
treated with water, by the application of concentrated solu-
tions, as of sugar, salts, albumen, &c., as well as the restoration
of motion by means of water, after treatment with too concen-
trated saline solutions, are circumstances in favour of Anker-
mann’s views, I would remark, that the Infusoria and cilia
also behave in the same way towards saline and other solutions.

The Opaline—minute Infusoria from the rectum of the
Frog, and the cilia of the Frog’s tongue—move in a solution of
common salt of 1 per cent., and of phosphate of soda of the

THE SPERMATIC FILAMENTS. 299

strength of from 5 to 10 per cent. In a solution of salt of
5 per cent., and of sugar of from 10 to 15 per cent., they
shrink up and become quiescent, though reviving upon the
addition of water: I have even succeeded in reviving the
Opaline, after they had been treated with a solution of
common salt, in the proportion of ;;th.

With respect to the development of the spermatic filaments,
I will here say only this much, that, from my latest observa-
tions, they are not developed in the nuelet of the spermatic
cells and cysts, but out of them. These neclei, which occur
either singly in small cells, or in numbers together, ree in
larger cells and cysts, become elongated, and push out from
one end a filamentary process, whilst the principal mass con-
stitutes the body of the filament. The spermatic filaments
are at first coiled up in the cells and cysts, and are afterwards
liberated by the perforation of these receptacles, in domg
which they frequently carry with them portions of the walls,
forming the appendages and hood-like cauls which have been
already pointed out by other observers.

( 300 )

NOTES AND CORRESPONDENCE.

Reply to some Remarks by F. Hi. Wenham.—In an article by
F. H. Wenham, Esq., of London, published in the ‘ Quar-
terly Journal of Microscopical Science’ for July, 1854, I have
noticed the following paragraph :—

‘‘These experiments [made by Mr. Wenham] will readily
account for the difficulty of discovering the markings or struc-
ture of a severe test when mounted in balsam; for as thus
seen it may be inferred that no aperture exceeding 85° can
be made to bear upon it, and this is even supposing that the
largest aperture object-glass that has ever been constructed is
used. Such being the case I am somewhat puzzled at an
announcement that appears to contradict this fact, coming
from one that must be considered as authority in these
matters. I refer to Professor Bailey, who, in a letter addressed
to Matthew Marshall, Esq., dated January 20, 1852, first
speaks of an American object-glass of very large aperture
(1724°), and its performance on the most difficult tests known,
and then proceeds to say, ‘In all these cases (and in fact
whenever I allude to a test-object) [ mean the balsam-mounted
specimens. The dry shells I never use as tests.’ This asser-
tion seems to me to be extraordinary, and very like saying
that an aperture of 85° or 90° will do everything that is re-
quired. I have invariably found that when very difficult tests
are mounted in balsam I cannot discover the markings, and
certainly the reasons herein given will account for it. It is
to be hoped that the American opticians have discovered
some new and peculiar principle in object-glasses, that will
render a smaller amount of aperture serviceable ; but however
this may be, I think that Professor Bailey’s statement requires
some explanation.”—Journ. Mic. Science, July, 1854, p. 215.

It is apparent from the above that Mr. Wenham has con-
vinced himself, both by “reasons” and experiment, that I
ought not to have seen the markings on delicate test-objects
when mounted in balsam; and that as he invariably found
that he could not discover these markings, therefore some
new and peculiar principle in object-glasses must have been
discovered to account for the success of American opticians.
In answer to this I would state that both in print, as well as
in private letters, I stand fully committed to the statement
that I can resolve the most difficult tests known even when
mounted in balsam. In 1849 I stated in this Journal, vol. vii.,
p- 268, that “the resolution of these tests mounted dry is so

MEMORANDA. 301

much easier than when in balsam, that objects thus mounted
are of little value in testing the powers of lenses, although
they may answer well when the end is to make out the real
structure of the object itself.” In fact I have up to this time
met with no object which, when mounted dry presents suffi-
cient difficulty to rank as a severe test-object, while there are
many which when balsam-mounted become very satisfac-
tory.

It is certainly no duty of mine to explain why Mr. Wenham
has failed in his attempts to resolve the balsam-mounted spe-
cimens, particularly as the resolution of such tests is a matter
of every-day amusement with microscopists in this country,
and I believe Mr. Wenham does injustice to the microscopists
and microscopes of London, in representing the English
glasses as incapable of doing as much. That the English
lenses are capable of performing well on balsam-mounted
objects of considerable difficulty I know by my own trials, some
of which are referred to in the following paragraph from a
paper recently published in the ‘Smithsonian Contributions
to Knowledge,’ vol. vii., p. 14 :—“I would here state that in
the spring of 1853, I resolved the Greenport Grammatophora
[balsam-mounted] unmistakably by a 1-4th of an inch objec-
tive made by Spencer, and subsequently by a 1-4th recently
made by Powell of London for Dr. Varnarsdale of New
York.”

As Mr. Wenham does not mention the names of the test-
objects employed by him, [ cannot say that they may not be
more difficult than any known to me; yet I feel no hesitation
in challenging him to produce an object resolvable when dry,
which I cannot resolve when balsam-mounted. I will also
state that | at present know of no test-object more difficult
than a supposed variety of Grammatophora stricta, Ehr., from
Halifax, N.S. This is as much more difficult than the Pro-
vidence Grammatophora, as the latter is more difficult than
the Greenport specimens. As a supply of the last two
varieties has been in London for two years they are probably
known to Mr. Wenham, and may have been subjected to
experiments by him. That the balsam-mounted specimens
of all these objects can be satisfactorily resolved is well
known to American observers ; and the following statement
given by Judge A. S. Johnson, in vol. xiii., p- 32 of this
Journal, is fully confirmatory of mewn experience. Speak-
ing of a new object-glass of 1744°, made in July, 1851, by
Spencer, the following remarks are made :-—

“The light failing us as evening was approaching, we did
not try in this way either the Amici test or the Providence

302 MEMORANDA.

Grammatophora, but in the evening we saw both these
objects [balsam-mounted ] satisfactorily resolved into dots by
unreflected oblique light from one wick of a common bed-
chamber lamp, burning oil, a homely but very effective
method of illumination for objectives of large apertures.”

It appears then that the resolution of balsam-mounted spe-
cimens of difficult test-objects can be accomplished, in spite
of Mr. Wenham’s arguments and experience to the contrary.
The error in his arguments will be sufficiently obvious to any
one who will trace the course of a divergent pencil of rays
out of the balsam instead of into it, as in Mr. Wenham’s
experiments, and it will then be seen that large angles of
aperture are as useful for balsam-mounted specimens as for
others. I leave the defence of large angles of aperture to the
professed optician, being well satisfied that, notwithstanding
the extraordinary attempts made by certain writers in Eng-
land to underrate the value of the improvements made in this
direction, no one who has once employed a properly-corrected
object-glass of large aperture will ever be satisfied with one
of a different construction.— Proressor J. BatLey, tn Ame-
rican Journal of Science and Arts.

Aperture of Object-Glasses in relation to Objects in Canada
®alsam.—In continuation of this subject I have to bring for-
ward a few experiments recently made, for the purpose of
viewing objects with the fall aperture of the object-glass,
when mounted in Canada balsam.

The fact that balsam does diminish the angle of aperture
of the microscopic object-glass when in action for viewing a
structure, mounted in the substance of that or any other
refractive medium, has already been sufficiently demonstrated,
both theoretically and practically, in the papers of Professor
Robinson and myself; and I consider that no further proofs
are requisite for establishing the truth of a position, which a
few simple experiments can be made to convey the most
direct conviction to unassisted eyesight, and which is so
strictly based upon the very first laws of incidence and
refraction, A fact so obvious as this can only be disputed
for two reasons—either ignorance of these laws, or a doubt of
their accuracy. To argue the point on one or both these
grounds would be beyond my province or capacity ; I, there-
fore, take this as a reality not to be disputed, and as such
proceed on the strength of it.

The sharpness and beauty with which some test-objects are
displayed under the diminished aperture, consequent upon
balsam-mounting, is upon first consideration rather surprising,

MEMORANDA. 303

and tends to show analogically the very great increase of
distinctness that would be obtained if the object could be
seen in the same medium with the full aperture of the object-
glass. Having been rather curious to know if objects in
balsam could be observed under such an advantage, I have
tried a few experiments, which were successful in their
results.

I first took a small hemispherical lens, of about 1-90th of an
inch radius, and cemented it over a selected specimen of one
of the Diatomacee (N. sigma) with Canada balsam, in the
manner represented by the annexed diagram. A, the object;

b b, slide upon which it is mounted; ¢ c, hemisphere of glass
covering the object; dd, pencils of rays diverging frome the
object—these may also be considered to represent thie aperture
of the object-glass. It will be seen from the position of the
object, that each ray of light passing from that point through
the surface of the hemisphere, will be transmitted in straight
lines, in a radial direction, without undergoing any refrac
tion; the consequence of witch is, that the full and undi-
munished aperture of the object-g lass is made to bear upon
the object.

If an object is already covered with thin glass, it may be
surmounted with a lens, so far short of a hemisphere as the
thickness of the cover, which of course amounts to the same
in effect as if the lens were hemispherical. I have a specimen
of P. formosum, mounted in this manner, by which the
markings are remarkably well displayed. A more simple
method of obtaining a similar result is by the following
course of proceeding :—Spread some of the desired forms of
Diatomacee upon a glass slip while in a moist state, and when
dry, scatter a number of small fragments of hard Canada
balsam upon the same surface ; apply heat very gradually, and
these will each run into the form of a spherule; they will

304 MEMORANDA.

next slowly sink into a shape approaching to that of a hemi-
sphere. Before this figure is quite completed, place the
slide under the microscope, and ascertain if any one of the
nodules of balsam exactly covers a fair specimen, if not, the
trial must be repeated with a fresh slide. Having found an
object properly situated under the particle of balsam, the
next step is to bring the latter down to the form of a hemi-
sphere, by the further aid of heat very cautiously applied.

The nodule of balsam, having been too spherical in the
first instance, will now gradually sink, and must be re-
peatedly tested under the microscope till the perfect hemi-
sphere is obtained, without any refraction being produced on
the rays from the object in the centre. The criteria for
knowing this are :—First, the object under the balsam must
be in the same plane of focus as similar dry objects outside;
secondly, the balsam object must not appear magnified more
than its uncovered fellows; and thirdly, the balsam-covered
object should not require a different adjustment from the dry
ones on the same slide. The existence of these combined
conditions indicate a perfect hemisphere.

When an object is seen under these circumstances, it at
once shows the great increase of distinctness that is to be
obtained in the structure of the more difficult Diatomaceous
tests when they are thus viewed in Canada balsam, with the
full aperture of the object-glass. Markings, which in the
neighbouring dry objects of the same character are scarcely
discernible, are sharply and distinctly visible under the
balsam hemisphere with the same illumination.

The luminosity of the field of view around the balsam
object is many shades darker than in the uncovered portion
of the slide, which appearance is caused by the diminished
angle or cone of rays of the illuminating pencil. From this
fact it is evident that the theoretical perfection of mounting
objects in this manner would be to enclose them exactly in
the centre of a minute sphere of balsam. In this case the
pencil of rays, both from the achromatic condenser and object-
glass, would pass directly to the object without refraction or
diminution; but I must confess that I have not been success-
ful in effecting this. It is very easy to form a sphere of
balsam at the end of a needle-point of any required degree
of minuteness, but very difficult to coax an object into the
centre of such a spherule.—F. H. Wenuam.

Microscopical Conversaziones. Few events have excited more
interest amongst microscopical observers than two soirées,
given by Mr. N. B. Ward, as Master of the Apothecaries’

MEMORANDA. 305

Society. ‘Those who have used the microscope for many
years in London will not have forgotten the pleasant reunions
at Mr. Ward’s house in Wellclose-square, when this instru-
ment was in its infancy, and when it required some courage
to confront those who maintained that at best it was a toy,
and its use a loss of time. The soirées of March 7th and
April 11th might well be regarded by Mr. Ward and his
friends as a vindication of their early zeal, and a triumphant
demonstration of the value and importance of the instrument
whose first successes they had witnessed, and whose influence
on human knowledge has more than realized their warmest
anticipations. The rooms at the disposal of the Apothecaries’
Society were well adapted to entertain a large audience, and.
perhaps in their history were never more gracefully employed
than in presenting what has been effected by an instrument
that has so largely contributed to the advancement of medical
science. On each occasion the walls of the large hall
were hung round with diagrams and drawings, exhibiting
enlarged representations of various objects observed by the
microscope. ‘They were arranged according as these were
from the mineral, vegetable, and animal kingdoms. Each
kingdom was again stbdivated into particular groups ; and
beneath these diagrams, on tables, were placed microscopes,
by which could be examined either the objects themselves
which were represented, or others allied to them. On both
occasions nearly one hundred microscopes were exhibited.
All the best forms and the newest apparatus might be seen
at work. Mr. Shadbolt, Mr. Brooke, Mr. Furze, and Mr.
Wenham, were superintending their respective methods of
illumination, The ingenious machine of Mr. Peters’, de-
scribed in the Transactions of the Microscopical Society, in
the present number of our Journal, was exhibited at the
second soirée for the first time; and writing produced upon
glass which defied the highest powers of the best microscopes
to decipher. Mr, Rainey and Professor Quekett exhibited a
large number of very beautifully injected specimens of animal
tissues. Amongst a variety of other objects Mr. Rainey
exhibited the curious glands in the frog’s skin, described by.
him in the present number of the Journal. Mr. Mummery,
of Dover, to whom science is indebted for many valuable
observations on marine animals, brought with him a quantity
of living specimens, and thus enabled a large number of
persons to witness, for the first time, the beautiful movements
of the Cilio-brachiate Polyps, the currents in the Sponge,
and other objects. Mr. Cook, the artist, whose Fern cases
are:almost as celebrated as his pictures, exhibited a great
VOL, III. x

306 MEMORANDA.

variety of specimens of the fructification of Ferns and Mosses.
The same class of objects were exhibited by Mr. Loddiges.
Mr. Bowerbank exhibited a series of the anchor-like processes
from the Holothuriade and Polyps. Mr. Varley exhibited
Chara, Valisneria, and living Animalcules. The Rev. J. Reade
exhibited a series of crystalline bodies ; whilst Mr. Woodward
threw a new light on every object by his beautiful polarising
apparatus. Plants, pictures, and objects of general interest
crowded the tables; but these were rather the adornments
than the substantial entertainment of the evening. Were we
to give an account of all that was worth seeing, it would take
up too large an amount of our space. We have felt ourselves
justified in giving these soirées this notice, both on account
of the respect we feel for the Master of the Apothecaries’
Society, at whose suggestion these interesting soirées were
arranged, and for the intrinsic benefit which must arise from
presenting to the mind at one time so large a number of the
facts which have been discovered by the aid of the micro-
scope. We are glad to be able to add that the friends of
Mr. Ward are raising a subscription for the purpose of pre-
senting his portrait to the Linnean Society, to be placed
amongst the collection of portraits of distinguished naturalists
in the meeting-room of that Society.—E. L.

Cheap Microscopes.—We announced in our last number that
the Society of Arts had offered two prizes for cheap micro-
scopes. From the following extract from the Report of the
Committee of that Society it will be seen that it has succeeded
in obtaining this desirable object :—

‘‘The important position which the Microscope now holds,
not only in relation to pure but to applied science, and its
great value in assisting to form those habits of observation
which it is the object of all sound education to impart, in-
duced the Council to believe that the promoting the pro-
duction of a good instrument at a price which should render
it more readily accessible to the many, was an object worthy
of the Society ; and, accordingly, under the advice and with
the assistance of a Committee, composed of Mr. Busk, F.RS. ;
Dr. Carpenter, F.R.S.; Mr. Jackson; Dr. Lankester, F.R.S. ;
Mr. Quekett; and Mr. W. W. Saunders, F.R.S., the follow-
ing prizes were offered :—

For a School Microscope, to be sold to the public at a price not exceeding
10s. 6d.—The Society’s Medal.

For a Teacher’s or Student’s Microscope, to be sold to the public at a
price not exceeding 37. 3s.—The Society’s Medal.

The Council undertook to purchase 100 of the smaller, and

MEMORANDA. 307

50 of the larger instruments for which the medals should be
awarded,

“The members will be glad to learn that for these prizes
there have been numerous competitors. After most careful
examination of all the instruments by the Committee, they
unanimously reported to the Council that the instruments
sent in by Messrs. Field and Co., of Birmingham, fulfilled
all the conditions required, and the Council have, therefore,
awarded to that firm the medals offered, on Messrs. Field and
Co. entering into the necessary undertakings to comply with
the requirements of the Prize List. ‘The Council congratulate
the members on this result. Those members who are desirous
of securing any of these instruments, which will shortly be
supplied to the Society by Messrs. Field, at a discount of
10 per cent., should at once send in their names to the
Secretary.’”—Excerpt Annual Report of the Council of the
Society of Arts to the Members, presented at the General Meet-
ing, June 13, 1855.

On “Species” of Diatomacex.— In your Journal for January
Professor Smith has made some valuable observations on what
is a species among Diatomacee, in which he enforces the
necessity of studying these beings in the recent state before
one can decide on what ought to be reckoned distinct. This
is the more necessary as it appears to me that neither size of
the frustules or distance of the striz are sufficient to distin-
guish species, unless we allow to each a very considerable
range of variation.

What are called “species” in Diatomacee may be viewed
under a twofold aspect :—1st. A species as it exists in nature,
requiring a study of every state from the sporangium to the
sporangium-bearing individual: 2nd, As serves the purposes
of the microscopist, who gives names to every difference of
form or size he observes that is not already figured. To the
latter class may be referred most of Ehrenberg’s, Kiitzing’s,
and Gregory’s species ; and it would be preferable to indicate
them by 1, 2, 3, &c., to giving names to each, until Smith or
some other naturalist can ascertain to what genuine species.
such forms may be referred. It is a natural species alone
which is worthy of the attention of scientific men.

A diatom increases in two different ways—by sporangia,
and by self-division, The length of time before a diatom
produces sporangia probably varies considerably in different
genera, and even in different species, but seems rarely, if ever,
to be less than three or four months. On the other hand the
power of self-division, although supposed by some to belong

x 2

b

308° MEMORANDA.

only to the mature frustule, seems really to exist at a very.
early age, as soon indeed as a frustule is formed from the
sporangium. Between the young state and the fully-formed
or sporangial one there must thus be a considerable difference
in size; and, as the number of frustules (the produce of one
sporangium by self-division) increase in a geometrical pro-
gression, we may always expect to find many more of the larger
than we did a short time previously of the smaller size, in the
same pool. All the frustules from the same sporangium
exhibit probably nearly the same size at the same age ; but in
the same locality other sporangia may have been deposited, so
that we find the same species of different ages or sizes mixed
together. ‘The minimum and the maximum state is therefore
one of the points that require to be decided on by naturalists
before we can form a definite idea of any one species.

The striz on the valves of a species requires also to be
studied; and here the question arises, is the distance between
the striae, or their number in -001 inch, constant? or does
the distance vary with the size of the valve, the number on
the entire valve being constant, when the frustules are all the
produce of the same sporangium? So long as this remains un-
determined by actual observation, it is of no use counting the
number of striz in a given space, or of talking of any species
being a test for object-lenses. Mr. Sollitt, of Hull, in giving
the number of striz of Pleurosigma quadratum and angulatum
(Microscopical Journal, II., p. 62, when by P. angulatum he
meant P. quadratum, and by P. strigosum is meant P. angu-
latum of Smith), points out a considerable difference between
the distance of the striz in smail and large specimens, and
that they are more distant in the latter; as however he does
not give the exact length of the frustules, nor say that the
valves were found in the same gathering, or if obtained from
the same locality at some weeks’ distance of time, no positive
conclusions can be drawn from his measurements. So far as
my own observations go, the number of striz in the entire
valve is tolerably constant, whether small or large, when ob-
tained at the same season and from the same locality ; and
consequently the actual number in ‘001 in. is of less conse-
quence than generally supposed, unless we multiply that
number by the length of the valve. Smith’s 6 and y of Pleu-
rosigma Balticum seem to have nearly the same total number
of striz, as in his a; but the first is about half the size of y,
and the other about one-third; so the striz in these ought to
be from two to three times closer than in a, and this agrees
well with observation: these two, then, cannot be considered
in the light of warteties of a, but merely a younger state of the

MEMORANDA. 309

same diatom, Other instances might be mentioned in which
the total number of striz is more constant than the number in
‘001 in. It is obvious that if the number in ‘001 in. be constant
at all ages, we must allow that in passing from the youngest
state to maturity the valves have the power of adding new
striz as they grow larger, but whether these additions are at
the extremities or at the centre no one has taken the trouble
to investigate. It may be alleged that the new valves formed
by the process of self-division acquire more numerous striz
than before; but while it is generally conceded that one of
the old valves remain in each frustule, this explanation can
scarcely be admitted, unless we are prepared also to allow
that there may be a great dissimilarity in the striae between
the two valves of the same frustules. If the total number of
striz in the valves remain constant, we must suppose the striz
to separate slightly as this valve enlarges ; and this supposi-
tion appears to me more in accordance with observations
hitherto recorded, although, no doubt, such observations have
not been made directly in reference to this point.

If the number of striz on the entire valve be found more
constant than the number in a given space (and here some
allowance must be made for the produce of different sporangia
not being identically the same either in size at the same age,
or in the precise number of striz to each valve), we may often
have a criterion whereby to decide whether a frustule be the
young state of a species or a distinct species or variety. I
have alluded to the 8 and y of P. Balticum not being
entitled to rank as varieties, any more than a lamb is a distinct
variety of a sheep; but, on the other hand, if we examine
Nitzschia dubia of Smith, we shall find not only that his 6
is much smaller than the a, but that while the striz of a are
difficult to be resolved by a } those in ( are readily made out,
being more distant. The small state here has more distant
strie than the large one, and although sometimes mixed in the
same gathering cannot possibly be the young of the other ; it
may form a peculiar variety, but my observations tend to
allow it the rank of a species, if indeed it do not belong to a
different genus,

Sufficient attention has not yet been paid to the sporangial
state of the diatoms; from the. observations recorded by
Thwaites, Smith, and others, different genera seem to follow
different laws on the subject. In Navicula this state appears
to be always accompanied by a great dilation of the frustule,
and the formation of a strong line or band between the median
line and the margin ; sometimes the new line is nearly straight
and parallel to the median line except near the nodule, with

310 MEMORANDA.

which it seems connected ; sometimes it is curved ; but whether
both structures occur in the same species, or are indicative of
different species, no evidence has hitherto been adduced.
Smith’s figures 152a*, 154a, and 274a, may be taken as
examples of the one, and 152a, 153a, and particularly 153@
and 154a*, of the other. The striz appear, however, to pre-
serve nearly the same inclination to the new or intermediate
lines which they did in the non-sporangial state to the median
line; and hence the direction of the striz is not sufficient of
itself to distinguish species, however good a character it may
afford, unless regard be had to the peculiar state of the frustule.

Perhaps I may be allowed here to remark that from the
days of Linnzus it has been a maxim, although specimens be
distributed or figures given with names, such names are held
to be unpublished unless clear and precise specific and generic
characters be given along with them; and that he who gives
such characters is not bound, except through courtesy, to
adopt or refer to the names attached to new figures. The
reason is obvious; specimens or figures only exhibit one form
of the species, and afford no information as to its limits, and
consequently the same author may, from ignorance of the laws
on which species are to be founded, give representations of
several forms of the same species; such names, if all the
forms were specifically distinct, may be good, but bad when
they are to be united; the describer or naturalist must, there-
fore, not be hampered by the errors of the artist or microsco-
pist who preceded him. In Ehrenberg’s Mikrogeologia, the
most unphilosophical work ever published on Diatomacee,
not one species, although supposed new, is characterized; and
unless one has samples of the same deposit he has depicted,
it is quite impossible to guess with any degree of certainty
what he intends, unless in some very rare instances. His
Biblarium glans is readily seen, no doubt, to be the well-
known Tetracyclus lacustris, of which Ehrenberg appears
ignorant, and his Synedra ? hemicyclus to be Eunotia fala of
Gregory, but few others can be so readily made out. In this
respect Kiitzing’s works have an advantage over Ehrenberg’s ;
but in many cases Kiitzing merely derives his specific cha-
racter from Ehrenberg’s figures and not from the diatom
itself, thus adding to the confusion. In the same way in your
Journal] are several papers by Dr. Gregory, accompanied with
figures, but as no specific characters are assigned the figures
lose their value, as no one is bound to adopt the names there
given.

In characterizing species a great mistake has crept in of
late years not only as to diatoms, but as to flowering plants;

MEMORANDA. 811

a species is defined, and then we get 8, y, 4, &c., noticed as
varieties, each with characters at variance with the character
of the species. A genus must be characterized so as to
include every species referred to it; and in the same way a
species must have a character that will include all its varieties,
or at least not exclude any one of them. No one has a right
to say which variety is the type of a species, when all may
have arisen from the same original seed; the primitive form
may be 8, or «, or A, of that we are totally ignorant. All we
can do is to arrange the varieties according to some arbitrary
rule, and to define each, a as well as 0, or 7; the peculiar
character of a cannot be incorporated with the diagnosis of
the species without doing violence to the other varieties, and
in fact separating them as distinct species, although the author
has not had the courage to do so, from indeed feeling con-
vinced they are not so.

Although I consider the distance between the striz to
depend considerably on the age and size of the frustule, I
wish it to be distinctly understood that as yet we have not
sufficient information whether the number of stria may not
also vary slightly in the same way. It is possible that both
variations take place ; but until the law connecting them be
ascertained, all attempts to derive specific characters from the
strie are futile, if not injurious, to the science, unless we
allow a very considerable range, so great indeed as to destroy
the utility of such characters. If, as some microscopists
think, the striz are the walls, and dots the angles formed by
the walls of minute compressed cellules, the surface of the
valve of a diatom ought to be compared with the cuticle of a
flowering-plant, which consists of cellular tissue so highly
compressed that the upper and lower walls touch each other,
leaving the lateral ones in the form of reticulating veins, these
vein-like reticulations having a certain thickness as well as
height: in viewing these by direct light, we see only the
breadth of each line, while obliquely, or by oblique light,
causing an oblique shadow or picture to enter the object-glass,
we see also its height, and therefore a greater surface of the
reticulating lines reaching the eye by oblique than by direct
light, we see these lines more distinctly. If the strie of
diatoms be formed in that way, we might easily understand
that the ease of making them out does not depend on the
distance from each other so much as on the breadth of the
lines or dots in connexion with their elevation ; and therefore,
although the actual distance of such be the same, we may
resolve some frustules of the same species more easily than
others. Diatomacee are thus not so good tests for the micro-

312 MEMORANDA,

scope as supposed, unless the same slide be used by all
observers.—A. ;

On a New Locality of Microscopic Test-objects.— In a Smith-
sonian memoir published in February, 1854,* I have described
and figured a species of Hyalodiscus from Halifax, Nova
Scotia, which appeared to me to be admirably fitted for a
test-object, inasmuch as its circular form, with radiant and
curved lines of great tenuity proceeding in all directions,
renders it unnecessary ever to change the position of the
shell when in the field of view in order to secure the best
possible direction of the light. Whatever its position, on
account of the perfect symmetry of its form and markings,
some portion must always be in the best possible position with
reference to the oblique light used for its examination. Unfor-
tunately, the Halifax specimens of this beautiful object
appear to be quite rare, | am therefore happy to announce
the discovery upon various Alge from Monterey, California,
of an inexhaustible supply of a species of Hyalodiscus closely
allied to the Halifax species, and answering equally well as a
test-object. I find it so convenient as a test-object when _
balsam-mounted that I am sure it will find favour with lovers
of the microscope-——Proressor J. BatLEy, in American
Journal of Science and Arts.

Memoranda on Flies’ Feet.—In the Journal, Vol. 111., p: 230,
Mr. Tyrrell, of Newcourt, remarks, “ In confirmation of
Mr. Hepworth and other naturalists, that the use of the
cushions beset with hairs terminating in glands secreting a
glutinous substance, is to attach the foot to the surface upon
which the insect walks by means of such secretion, and not
by suction, | would suggest that the hooks on the feet of flies
are intended not to attach the Fly to anything, but to be used
as fulcra, or props, which it can push against when it wishes
to detach the cushions. Without the hook-shaped props, the
Fly, when once stuck fast, must remain so.’

Mr. Tyrrell alludes to a paper in the previous Volume on
the ‘ Fly’s Foot,’ in which I state that this fluid is not essential
for that purpose (of attaching the foot), and I speak of the
tubules as suckers. My observations have led me to the fol-
lowing conclusions: viz.: that the termination of each hair or
tubule is a sucker, and the secretion is only to increase its

* “Notes on New Species and Localities of Microscopical Organisins,’
by J. W. Bailey, in ‘Smithsonian Contributions to Knowledge,’ Vol. vii.,
p.' 14. ;

MEMORANDA. 313

power, on the same principle as that on which the boy wets
his leather to attach it to a stone; that the fluid is not of a
glutinous nature, as it evaporates very rapidly, and I have not
been able to detect anything on the glass afterwards, when
the foot has been perfectly clean: that each sucker is under
the influence of the will, and has either muscular fibres or
other elastic tissue, whieh answers the same purpose (vide
Professor A. Ecker’s paper, Journal, Vol. ii., page 111). If
the secretion were glutinous, and the foot mae to be attached
for some time (twenty or thirty minutes, as I have often seen
it) to the same spot, it would get so firmly fixed, that if forci-
bly raised by the leverage of the hooks, these exceedingly
delicate structures would be destroyed. The Dytiscus, when
under water, is able to hold himself so firmly on glass, as to
require the weight of many pounds to overcome the power
with which he is attached ; whereas when the glass is dry,
there is no difficulty. I have seen a Fly (under the microscope
feet upwards) make one foot the centre of motion, and move
the body so far round it, as to cause the leg to form a consi-
derable angle (15 to 25 degrees). I conceive that, to overcome
the adhesion, if produced by a glutinous secretion, which is
sufficient to fix the foot under these circumstances, it would
require such an amount of power by means of leverage, as
would readily tear through the delicate ends of the tubules.
At other times, [ have seen the insect so far loosen its hold, as
to allow the flap (cushion) to drag along the glass, and refix it
firmly, without lifting it off the glass. The round portion of
the flap of the blow-fly is about the 1-100th of an inch in
diameter, which contains upwards of 6,000 suckers ; the trian-
gular part, extending for attachment up to the leg, will be about
a quarter more of that area: the flaps of one foot, then, will
have 15,000 or 16,000 points of attachment. Diagrams, Nos.
1 and 2, are further illustrations of the same principle. No.
1—Hairs from the pad of the foot of a small Curculio beetle ;
they expand into the form of a trumpet, and where the ex pan-
sion commences they appear corrugated, and the corrugation
is continued to their extremities ; : the expanded parts are ex-
tremely attenuated, so much so, as to require a high power
and oblique light to make them out. These insects (not
being aquatic) Ales secrete a fluid for the same purpose as the
Fly: and I can imagine that if, after the ends have been at-
tached and iostonedl these folds could be put upon the stretch,
thereby lengthening the tubes, and consequently having a
tendency to “produce a vacuum, they would form an excellent
apparatus for attachment.

No. 2 is the pad of a variety of Cymbex lutea, which has

314 MEMORANDA.

hairs similar to those of the flap of the Fly; the wing of this
insect possesses hooklets.

No. 1.—Hairs of Curculio Beetle. a, a, a, shaft of hair;
b, b,b, expanded ends. 400 diameters.

No. 2.—Leg of Cymber lutea. a, b, c, d, cushions at each
joint. 24 diameters.

No. 3.—Enlarged view of c, showing hairs on the under
surface. 110 diameters.

Joun Hepwortn, Croft's Bank, May 31, 1855.

On Finders.—Contributors to these Notes have suggested
many successful contrivances for indicating the exact position
of an object in a slide, but they all involve an amount of
complex arrangement which is inconvenient in their practical
application under a moderately-high power. A small, narrow
ring, painted round the object on the surface of the thin glass
cover with Prussian blue water-colour, will at last prove the
most serviceable, because it can at once be seen, when in the
field, without altering the focus, and more readily than a ring

MEMORANDA, ols

marked by a diamond, to which the focus must be first
directed. A little practice will soon lead to dexterity in
estimating the position of the object when the slide is on the
stage, and in making a touch or a line of colour thereon as a
guide for the position of the ring ; the work can be examined
under the microscope, and corrected and finished in any
convenient position. A red ring painted outside the blue
will render it more conspicuous, and assist observation when
under the microscope ; the colour should be used rather thick,
and the whole should have a slight protecting coat of gold size
or varnish. As objects are mounted for other purposes than
to furnish neatly the drawers of a cabinet, the facility in
using slides thus permanently marked will outweigh the
objections to the unsightly appearance.—J. H.

Memoranda on the Employment of Artificial Sea-Water in Marine
Aquaria. —Early in the summer of last year | commenced some
experiments on artificial sea-water, made according to the
formula proposed by Mr. P. H. Gosse; the ingredients in
the proper proportions having been procured from Mr. Wm.
Bolton, 146, Holborn Bars, London. In it I have successfully

maintained alive the following marine productions :—

ANIMALS. Mollusca.

Zoophytes. 26, Cynthia momus.
1. Clava multicornis. | 27. Pecten opercularis.
2. Hydractinia echinata. 28. Doris pilosa.
3. Actinia Mesembryanthemum. 29. ,; , tuberculata.
4 »> crassicornis. 30. Eolis coronata.
5 pe bellis, 31. Nucula cristata.
6 »» parasitica, 32. Lamellaria perspicua.
7 » Dianthus. 33. Nerita
8 » anguicoma. 34, Littorina littorea.
9 » Clayata. 35. Rissoa Ps
10 », Aurora. | 36. Trochus zizyphinus.
11. Anthea cereus. 37. Purpura lapillus.
12, Caryophyllia Smithii. | 38. Chiton fascicularis and C.
13. Sertularia polyzonias. leevis.
14 a filicula. |
15 ~ pumila, | Cirrhipedes.
16. Flustra membranacea. | anes
17. Bowerbankia imbricata. He Pelanns. balanoigess
18. Vesicularia spinosa. | i

Annelides. VEGETATION.
19. Serpula contortuplicata.
20. .,,. + ‘triquetra. | 41. Ulva latissima.
21. Sabella ? 42. Enteromorpha compressa.
22. Terebella conchilega. 43. Cladopora ?
23. Spio vulgaris. 44. Phyllophora rubens.

24. Nereis

: 45. Bryopsis plumosa.
25. Pontobdella muricata. |

316 MEMORANDA.

The ‘only accommodation provided for the whole of the
above is a series of glass jars and vases placed on shelves in
the windows of an ordinary London dwelling-room, the largest
glass not exceeding three gallons capacity. It is not pre-
tended, however, that those animals, which are notoriously
short-lived in confinement (such for instance as Nos. 27 to 32)
even under the most advantageous circumstances of space, had
their existence more prolonged with me: I would merely state
that I have met with no more difficulties with the artificial than
with the actual sea-water, under the same conditions. Nos. 1,
(this is now in the gravid state represented in Johnston's
Zoophytes, Plate 1), 2 and 16, made their appearance, spon-
taneously as it were, on some empty shells and other debris
placed in the water six months before, and which had not been
changed during the whole of that period. Nos. 3, and 5 to 10,
are very hardy with me, but No. 4 is in general precarious.
Nos. 13, 14, 15 lived in a quart jar for three months, at the
end of which time [ disposed of them, after they had added
hundreds of new cells to the polypidoms. Nos. 19, 20, 21
added considerably to their tubes, the new portion being in-
dicated in No, 20 by its superior whiteness, and the rate of
increase being about a third of an inch in six months. On
the lst of May, I counted ten young of this species, the parents
having been in my possession since September 4. Colonies of
No. 23 are very vigorous and active, but I find that they have
a period of rest from soon after midnight to about 4 or 5 P.M.

Many of the Actinie@ mentioned in the above list are the
same individuals which I had at the commencement of my
experiments, and most of them have brought forth young
abundantly. ‘The development of Nos. 16 (this especially),
17, 18 have afforded me many weeks of most interesting ob-
servation. In Nos. 39 and 40, I have noticed that frequently
the cirrhi have began to play as quickly as ever, even after a
period of inaction so long that I have supposed the animals to
be dead.

In the vegetation, I find that No. 42 is the most effective in
the evolution of oxygen. No.41 stands next. No. 44 is apt
to decay if not placed in a shaded spot, but it is always inte-
resting from the quantity of parasitic animals usually found
upon it.

I trust that these desultory observations, hastily thrown to-
gether, but scrupulously containing nothing that I have not
personally witnessed in my own collection, will have the effect
of increasing the domestication of the interesting productions
of our shores.—WrtiiAM Atrrep Lioyp, 164, St. John Street
Road, Islington, London, June 6, 1855.

GBbEad

PROCEEDINGS OF SOCIETIES.

Roya Society.

Mr. Savory, ‘‘ On the Development of Muscular Fibre in Mam-
malia.”

Tue author's observations were made chiefly upon fcetal pigs; but
they have been confirmed by repeated examinations of the embryos
of many other animals, and of the buman feetus.

If a portion of tissue immediately beneath the surface from the
dorsal region of a foetal pig, from one to two inches in length, be
examined microscopically, there will be seen, besides blood-cor-
puscles in various stages of development, nucleated cells and free
nuclei or cytoblasts scattered through a clear and _ structureless
blastema in great abundance. These cytoblasts vary in shape and
size; the smaller ones, which are by far the most numerous, being
generally round, and the larger ones more or less oval. Their out-
line is distinct and well defined, and one or two nucleoli may be
seen in their interior as small, bright, highly-refracting spots. The
rest of their substance is either uniformly nebulous or faintly
granular.

The first stage in the development of striated muscular fibre con-
sists in the aggregation and adhesion of the cytoblasts, and their
investment by blastema so as to form elongated masses. In these
clusters the nuclei have, at first, no regular arrangement. Almost,
if not quite as soon as the cytoblasts are thus aggregated, they
become invested by the blastema, and this substance at the same
time appears to be much condensed, so that many of the nuclei
become obscured.

These nuclei, thus aggregated and invested, next assume a much
more regular position. They fall into a single row with remarkable
uniformity, and the surrounding substance at the same time grows
clear and more transparent, and is arranged in the form of two
bands bordering the fibre and bounding the extremities of the nuclei,
so that now they become distinctly visible. ‘They are oval, and
form a single row in the centre of the fibre, closely packed together
side by side, their long axes lying transversely, and their extremiiies
bounded on either side by a thin, clear, pellucid border of apparently
homogeneous substance.

It is to be observed how closely the muscular fibres of mammalia
at this period of their development resemble their permanent form
in many insects.

The fibres next increase in length and the nuclei separate. Small
intervals appear between them. The spaces rapidly widen, until at
last the nuclei lie at a very considerable distance apart. At the
same time the fibre strikingly decreases in diameter; for as the
nuclei separate, the lateral bands fall in and ultimately coalesce.

318 PROCEEDINGS OF SOCIETIES. -

This lengthening of the fibre and consequent separation of the
nuclei is due to an increase of material, and not to a stretching of
the fibre.

Soon after the nuclei have separated some of them begin to
decay. ‘They increase in size; their outline becomes indistinct; a
bright border appears immediately within their margin; their con-
tents become decidedly granular; their outline is broken and inter-
rupted; and presently an irregular cluster of granules is all that
remains, and these soon disappear.

It sometimes happens that the nuclei perish while in contact,
before the fibre elongates ; but the subsequent changes are the same.

The striz generally first become visible at this period, imme-
diately within the margin of the fibre.

The fibre is subsequently increased in size, and its development
is continued by means of the surrounding cytoblasts. ‘These attach
themselves to its exterior, and then become invested by a layer of
the surrounding blastema. ‘Thus, as it were, nodes are formed at
intervals on the surface of the fibre. These invested nuclei are at
first readily detached, but they soon become intimately connected
and indefinitely blended with the exterior of the fibre. All its cha-
racters are soon acquired; the nuclei at the same time gradually
sink into its substance, and an ill-defined elevation, which soon dis-
appears, is all that remains.

Lastly, the substance of the fibre becomes contracted and con-
densed. The diameter of a fibre towards, or at the close of intra-
uterine life, is considerably less than at a much earlier period.

At the period of birth muscular fibres vary much in size.

The several stages in the development of muscular fibre, above
mentioned, do not succeed each other as a simple consecutive series ;
on the contrary, two, or more, are generally progressing at the same
time. Nor does each commence at the same period in all cases.

Sroxe Newineton Naturau History AND SCIENTIFIC SOCIETY.
April 24, 1855.

A PAPER was read by Mr. Richard Moreland, jun., ‘On the pro-
bable Structure of the Starch Granule.’ *

After pointing out the extensive occurrence of starch in the
vegetable kingdom, and its importance in an economical point of
view, and adverting to its chemical properties, the author proceeds to
discuss the structure of the grain itself. He illustrates his views
on this point by reference to the form of starch termed ‘ tous les
mois arrowrooi,’ the large grains of which are particularly fitted for
observation.

Noticing the views of Leuwenhoek, Rastail, Fritzsche, Schleiden,

* This paper, accompanied with elaborate figures, has been forwarded
to us for insertion; its length, however, renders this impossible, and we
have been compelled to content ourselves with the above abstract of Mr.
Moreland’s views.—Editors of Quarterly J ournal of Microscopical Science.

PROCEEDINGS OF SOCIETIES. 319

Martin, &c., Mr. Moreland declares himself in favour of those who
conceive with Schleiden and others, that the starch granule is con-
stituted of successive layers or laminz, inserted one within the other,
and whose edges are represented by the concentric markings seen
on the surface of the grain. He advocates, in fact, the view pro-
pounded in a late number of the ‘ Quarterly Journal of Micro-
scopical Science,’ by Professor Allman.

The principal additional argument relied upon by Mr. Moreland
in support of this opinion, appears to be derived from the use of
polarized light in the examination of the grain, whilst undergoing
solution in sulphuric acid. Observing that the crop of polarization
continues to be well defined after the dissolution, or, as he terms it,
the disintegration of what he regards as the outer layers by the action
of the acid, he conceives that this circumstance is sufficient to indi-
cate that the grain is constituted of a succession of such lamine of
like consistence throughout.

He also notices the effect of chloride of zine upon the starch
grain, which, he says, ‘‘ instead of disintegrating the vesicle, causes
it to expand slowly in the form of a thin membrane.”

The paper concludes in nearly the following words :—

“ That all starch granules, which exhibit elliptical or striated
markings, and are also capable of polarizing light, are composed of
a series of vesicles (hollow ellipsoids), any deviation from this form
being produced by circumstances attending their formation. These
vesicles are thicker at that extremity of the granule from which
they receive their sustenance [addition to their substance], conse-
quently the nucleus is situated at the opposite extremity. The gra-
nules are attached to the cell-wall by that extremity which is
farthest from the nucleus; the thickness of the vesicles being indi-
cated by the distances between the markings. They are, moreover,
enclosed one within the other, and it may be proved [the author
conceives] by sound reason and observation that these vesicles are
deposited and formed upon the exterior surface of the one previously
existing, and that each vesicle, upon its final development, is a hard,
colourless, transparent, homogeneous substance, all being chemically
and physically identical, save that a portion of any foreign substance
may be deposited with any of the vesicles,” &c.

( $20 )

ZOOPHYTOLOGY.

Class. POLYZOA.
Order I. P. INFUNDIBULATA.
Sub-order 1. CHEILOSTOMATA.

§ 1. Articulata.
§§ 2. Bi-multiserialaria.
Fam. SALICORNARIADA, Busk.
Gen. Onchopora, n. sp., Busk (“Oykos). .
Cells ventricose, coalescent ; not bordered by a raised margin. Ovicells
inconspicuous,

1. O. hirsuta, n. sp.? Busk. PI. III.

A long jointed corneous tube arising on each side on the front and upper.
part of the cell ; a raised median pore, below the mouth, which is produced
and subtubular.

? Cellaria hirsuta, Lamx. Hist, des Polyp. cor., p. 126. Pl. IL,
fig. 4, a, B.

Hab. New Zealand. Dr. Lyall.

The outward aspect of this species so closely resembles that of C. hir-
suta, Lamx., that, notwithstanding the apparent differences in the minuter
details, so far as they can be ascertained from the imperfect figure above
cited, Iam strongly inclined to regard them as most probably identical.
The polyzoary forms smail tufts, constituted of short truncated internodes,
united by a single large corneous tube, and having a hairy aspect from
the curious, jointed corneous tubes springing from each side of the cell,
The little median pore sometimes appears like a very minute avicularium,
but it is by no means clear that it is an organ of that kind. The corneous
tubes are clearly not vibracula; and as the perfect ones are closed at the
end, and free, they do not seem to be of the nature of radical tubes, such
as exist, for instance, in Cauda arachnoidea,

2.. O.. tubulosa, n. S.,, Busk... Pl. IYV., fig. 1.

Mouth of cell—very much produced, tubular; a median pore in front
of the cell.

Hab. Aigean Sea. E. Forbes.

The much-produced tubular prolongation of the mouth in this species,
at, the end of which there is no indication of a moveable lip, might at first
sight lead to the supposition that this form belongs to the second sub-
order of the Polyzoa; but further examination, and especially where the
tubular portion may be partially broken off, will detect the lip, at the
bottom of the tube, in the usual situation. ‘The absence of the corneous
tubes at once suffices to distinguish this from the preceding species, from
which it also differs very widely in external aspect. The polyzoary is not
constituted, as in that case, of short internodes, arising from each other in
a dichotomous arrangement, but is formed of cylindrical branches some-
times an inch or more in length, from which others arise at irregular
distances, and nearly at right angles, to that from which they spring, and
to which they are articulated, not by a single, wide corneous tube, but by
a bundle of smaller tubes, in number corresponding to the initial cells of
the new branch, It may be supposed to bear some resemblance to the
Cellaria cereoides of Lillis and Solander (PI. V., fig. b, A, B, C, D, E);

ZOOPHYTOLOGY. ool

and perhaps may represent a variety of the same species, which is also
stated to come from the Mediterranean.
3. O. mutica, n. sp., Busk. PI. IV., figs. 2, 3.
Mouth plain ; crescentric above, with a straight inferior margin.

Hab. Philippine Islands? or Australia?

A minute form, sufficiently distinguished from its congeners by the
above character. The polyzoary is constituted of short internodes, con-
nected by a flexible horny tube. The only specimen I have is very small,
and it is constituted of short internodes, composed of 8 or 10 cells. Its
habitat is doubtful, but I believe it to be one or other of those above
assigned. It is growing on a fragment of coral.

Some apology is requisite for the proposal of a new generic
term, to a form which has probably been long known under
another name ; but in the present case it appeared justifiable,
from the consideration that the term Cellaria, which is the
only one that could have been taken, has been understood in
so many senses; and that the species at different times in-
cluded under it have been so frequently subdivided into other
groups, as to render its continued use likely to produce much
confusion.

The species having articulated polyzoaries composed of
cylindrical internodes, in which the cells are disposed around
an imaginary axis, were originally confounded by Pallas under
his genus Cellularia, and by Solander under that of Cedlaria,
with many others, not possessing that peculiar characteristic.
The term Cellaria, however, was subsequently restricted by
Lamouroux to those polyzoaries, which had _ cylindrical
branches, or rather in which the cells were disposed around
a central axis ; but as this restricted sense of the term has not
been adopted by many subsequent writers, nor especially by
Lamarck, and as it has long since ceased to be applied to the
genus Salicornaria, it seems as well perhaps to dispense with
it altogether.

Other forms again have been confounded under the same
term Cellaria by several writers, among whom may be noticed
Reuss, in his account of the fossil polyzoa of the Vienna
tertiaries, who includes under it Vineularta, Defrance (Glau-
conoma, Goldfuss). Whilst Hagenow, on the other hand
(Die Bryoz d. Maastrich, Kneidebildung), adopts Vincularia
and ignores Cellaria. In Vincularia, proper, however, the
polyzoary is continuous throughout, and not subdivided into
internodes by flexible joints; so that there appears to be no
reason whatever for associating the two.

The following fossil forms might be referred to the genus
Onchopora ; and it would appear that no species belonging to
it occur in formations anterior to the tertiary, unless the

VOL. III. Y¥—Z

322 ZOOPHYTOLOGY.

Ceriopora oculata, Goldf. (Petref. Germ., Pl. LXIV., fig. 14,
p- 217), from the transition limestone, may be included
in it.
Cellaria duplicata, Reuss, 1. c., p. 62, T. vii., fig. 34.
» labrosa, Reuss, |. c., p. 63, T. vii., fig. 35.
» Michelini, Reuss, |. c., p. 61, T. viii., figs. 1 and 2.
(Vinculuria fragilis? Defrance), also in the Paris basin
(Michelin, p. 46).
» coronata, Reuss, l. c., p. 62, T. viii., fig. 3.
» scerobiculata, Reuss, |. ¢., p. 63, T. viii., fig. 4.
» Schreibersi, Reuss, |. c., p. 63, T. viii., fig. 8.
» Haweri, Reuss, l.'c., p. 60, 1. vill., fig. 9.
.. stenosticha, Reuss, 1. c., p. 64, T. viii., fig. 10.

We have here also given the figures of a species of E'schara,
which would seem to correspond very closely with the Mille-
pora cervicornis of Ellis and Solander, or with the Hschara
cervicornis of Lamarck (An. s. Vert., 2nd ed., t. ii., p. 267),
though not to that described by M. Edwards (Sur les Eschares,
p- 15, Pl. I. and PI. IL, fig. 1), under the same name, from
which it is undoubtedly different, as it is also from the
E. cervicornis in the British Museum Catalogue. Neither
does it correspond with the E. gracilis of Milne-Edwards.
From the former it differs widely in the shape of the mouth,
and in its tubular projection, and from the latter in the
absence of the median pore, and of punctation of the surface
of the cells.

But as I have not been able to refer to Marsigli’s figure
(Hist. de la Mer., tab. xxxii., fig. 152), with which Ellis and
Solander’s Millepora cervicornis is said exactly to agree, I find
it impossible at present to come to a definite conclusion in
the matter.

Provisionally, it would seem right to regard the present
form as the true Millepora (Eschara) cervicornis of Ellis and
Solander, and it might be thus characterized :—

E. cervicornis, Solander. Pl. IV., figs. 4, 5, 6.

E. ramosa, ramis subcylindraceis per angustis ; osculis prominalis tubu-
losis ; labio inferiori, medid denticulato.
Hab, Aigean Sea. E. Forbes.

The polyzoary is composed of slender, cylindrical branches,
in the older and thicker parts of which the cells become
deeply immersed, and the mouth appears like a raised nipple,
but within it may always be perceived the median denticle on
the lower lip.

JOURNAL OF MICROSCOPICAL SCIENCE.

PLATE I.
Illustrates Mr. Gorham’s Paper.

DESCRIPTION OF PLATE II.
Illustrating Mr. Currey’s Paper.

Fig.
1.—A thread of Trichia chrysosperma.
2.—The end of a similar thread acted upon by sulphuric acid. The
spiral appearance has vanished for a short space from the end.
3.—The end of a similar thread which had been soaked in oil of lemons.
The tip appears to have become flaccid, and the spiral marking
has partially disappeared.
4.—A thread of Trichia nigripes.
5,—A portion of a thread of Trichia Neesiana, acted upon by Schulz’s
solution.
6.—The tip of the same.
7 and 8.—Portions of threads of Trichia serpula.
9.—Portion of a thread of Trichia pyriformis.
10.—The membrane of Trichia pyriformis, unrolling spirally.

All the figures are highly magnified.

DESCRIPTION OF PLATE III.
In illustration of Dr. Allman’s Paper.

Figs. 1—8. Aphanizomenon Flos-aque.
Fi
1.—Fascicles of filaments, natural size.
2.—Three primary fascicles united into a larger bundle, magnified.
3.—The fascicles have broken up into their component filaments, which
have rearranged themselves into parallel wavy curves, slightly
magnified.
4,—A filament with two sporangia.
a, a, ordinary cells.
b, b, sporangia.
5.—A filament with a heterocyst. :
a, a, ordinary ceils. ~
b, b, heterocyst.
6.—Filament with a heterocyst after the application of a solution of
lodine.
a, ordinary cells.
b, heterocyst.
7.—A sporangium after the application of a solution of iodine.
8,—Portion of a filament in which several ordinary cells seem to be in
process of coalescence, in order to form a sporangium.

Figs. 9—17. Peridinea uberrima.

9.—P. uberrima in the act of swimming, viewed from the side of the
vertical furrow. The ocelliform spot and nucleus are visible
through the walls.

10.—The same viewed from the opposite side.
11.—The animalcule after having passed from a motile to a quiescent
state.
12.—The animalcule with the external vesicle ruptured, and the contents
escaping.
a, a, oil-globules.
b, nucleus.
c, ¢, brown granules.
13.—The nucleus isolated.
14.—The animalcule undergoing transverse division.
15.—The same after the application of a solution of iodine.
16.—Outline of nucleus, with commencement of transverse division.
17.—Transverse division nearly completed.

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DESCRIPTION OF PLATE IV.

Illustrating Prof. Gregory’s Paper on the Glenshira Sand.
Fig.
fe ee peatia Fala, 0. sp.
(Found in the deposits of Liineberg and Lillhaggsjon. See Vol. II.,
p- 104, of this Journal.)
2,—Nitzschia Sigmatella, n. sp.
(Found as above, but also in the Mull deposit, and, with all the
following figures, in the Glenshira sand.)
3.—Cymbella truncata, n. sp.
4.—Amphora Arcus, 0. sp.

5.— s incurva, D. sp.
6.— % angularis, n. sp.
7.—Cocconets transversalis, n. sp.
8.— . speciosa, D. Sp.
9.— 5 distans, ND. sp.
10.— = costata, . sp.

11.—Kupodiscus Ralfsii? var.
12.—Surirella fastuosa, var.
13.—Tryblionella constricta, n. sp.
14.—Amphiproa Vitrea, var. ?
15.—Navicula birostrata, n. sp.

16.— » rhombica, n. sp.
17.— » gastroides, n. sp.
18.— » erassd, 0. sp.
19.— 65 maxima, D. sp.
20.—Pinnularia Gastrum, Ehr.

21.— 5 apiculata,. 2. sp.
22.—Synedra Vertebra, n. sp.
23.— » wndulans, n. sp.

DESCRIPTION OF PLATE V.

Illustrating Mr. Huxley’s Paper on Noctiluca.
Fig.
1.—WNoctiluca miliaris, from above.
2.— The animal viewed from behind, showing the groove.
3.—A_ latero-inferior view, displaying the oral aperture, the cilium, the
tooth, a gastric pouch, and the anal (?) aperture.
4,—The oral aperture on a larger scale.
5,—Antero-superior view, showing the nucleus, the fibres and fibrils, the
tooth and the reproductive (?) granules.
6.—The superficial network of granules and fibrils.
a, Tentacle. b, groove. c, nucleus. d, tooth. e, gastric pouches.
f, anal aperture. g, radiating fibres and fibrils. h, repro-
ductive (?) granules.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE VI.,
Illustrating Dr. Johnston’s Paper on the Mosquito.

Fig.
fj 2siead of male mosquito, magnified 20 diameters.
2.—Orbital rings supporting the capsules.
3.—Auditory capsule (sectional view).

4.—T wo joints of antenna.
5.—Diagram of auditory (?) and antennar nerve.

DESCRIPTION OF PLATE VIL.,
Illustrating Dr. Webb’s Paper.

Fig.
6.—Is a side view of the Noctéluca miliaris, The conical appearance of
the tooth is seen in this position.

7.—A front view of the same parts. a, the outer surface of ‘ the tooth ;”
b, the oral aperture ; c, position of the supposed anal aperture.

8.—View in profile of the central depression.
9.—Sectional view of the central depression and tooth, from behind.
10.—The nucleus enveloped in a membrane with yelk-like matter.

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EXPLANATION OF THE PLATES
lilustrating Dr. Redfern’s Paper.

The drawings from which the Plates were executed were made by the
camera lueida, under a power of 140 linear diameters. Scales having
reference to the different figures are appended to each Plate. The whole
of the figures in Plates VII. VIII. and the first four in Plate IX. are
represented in the lithographs as magnified 180 diameters. Figs. 5 and 6
of Plate IX. are only enlarged 50 diameters, and have a separate scale
below them.

PLATE VII.
Fig.
1.—Horizontal section of Torbanehill coal, 2 inches from the top of the
seam, showing a three-lobed yellow patch with its radiate lines,
and a mass of substance in which the yellow matter is imperfectly
marked out into rounded or angular spaces by darker bands.

2.—Vertical section at the same part, showing irregularly elongated
yellow and reddish patches, bounded by dark lines, running in
the direction of the lamine of bedding; also a crystal, which
polarises light very powerfully.

3.—Horizontal section of the same block of coal 16 inches from the top,
showing irregularly rounded yellow bodies with dark outlines ;
much smaller polygonal spaces of more uniform size ; and a sec-
tion of a rounded vegetable capsule like a spore.

4.—Vertical section at the same part as the last, showing the yellow
bodies elongated in the direction of the lamin of bedding, with
their dark-brown boundaries projecting at the free edge, like
pieces of membrane or fibre.

5.—Horizontal section, and 6, vertical section, of Wemyss coal, showing
yellow bodies with radiate lines, similar to those in the Torbane-
hill coal, and like them rounded on horizontal sections and
elongated on vertical ones.

PLATE VIII.

1 and 2.—Horizontal and vertical sections of Methill coal.

3 and 4.—Horizontal and vertical sections of Capledrae coal, showing, as
well as the sections of Methill coal, similar yellow bodies to those
in the Torbanehill coal, rounded on horizontal sections, and
elongated in the direction of the lamine of bedding on vertical
sections.

5.—Shows spherical or polygonal membranous capsules, tubercular or
pilose on the surface (spores ?), found in great numbers on all thin
horizontal sections of Torbanehill coal.

6.—Similar bodies seen on vertical sections of the same coal.

PLATE IX.

TORBANEHILL COAL.

1.—Scalariform tissue abundant in the Stigmarie.

2.—Horizontal section, showing the action of heat on the upper edge of
the section.

3.—Vertical section, showing the relation which exists between dense
masses of vegetable tissue and the general structure of the coal.

4.—Horizontal section, showing what appear to be bands of fibre with a
reticulate arrangement.

5.—Vertical section passing through what appears to be a membranous
capsule, tubercular or hairy on the external surface, and smooth
within.

6.—Horizontal section, showing another view of a similar body to the
last.

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JOURNAL OF MICROSCOPICAL SCIENCE.

EXPLANATION OF PLATE X.

Figures illustrating Dr. Busch on Noctiluca.
Fig.
1.—-Noctiluca punctata, Busch (miliaris, E. and G.). a, border turned
in at the Ailus; b, sharp bordered rod; ¢, brown body (nucleus,
Quatref.) ; d, proboscis ; 7, brown corpuscles seen ir. the interior.
2 and 3.—Germs of Noctilucce found in empty saceculi.
eee development of the germ. c, brown body (nucleus); d, pro-
oscis.
5 and 6.—Young Noctiluce. b, rod; c, brown body (nucleus); d, pro-
boscis.
7.—Monstrous Noctiluca.
8.—Uhe granular body from the interior of the Noctiluca (fig. 1 f) highly
magnified.
9.—Luminous discs found among the Noctiluce.
10.—The minute bodies seated on the upper border of these discs.

Figures illustrating Dr. Allman’s Paper.

11.—Bursaria leucas, Ehr., magnified about 90 diameters.
a. Nucleus.
b. Contractile space.
c. Digestive vacuole filled with food.
d. Mouth.

12.—Ideal Section of Bursaria leucas.
a. Nucleus.
e. Dermal layer containing trichocysts, and covered with cilia.
f. Green globules forming a distinct stratum beneath the
dermal layer.
g. Granular colourless contents.

18.—A portion of the outline of the animal after the application of acetic
acid. ‘The trichocysts have become changed into long acicular
bodies, some of which radiate from the surface, to which they
still partially adhere, while others are scattered over the stage of
the microscope.

14.—A greatly enlarged view of the margin, to show the position of the
trichocysts.

Jf. Green globules.
g. Granular contents.
h. Trichocysts.

a. Cilia.

15,—Isolated trichocysts in a quiescent state.

16.—First stage of evolution—the trichocysts have become transformed
into spherules.

17.—Second stage of evolution—the spherules are replaced by a spiral
filament, which rapidly unrolls.

18.—Final stage of evolution—the completely unrolled filament lies as a
transparent spiculum in the field of the microscope.

k. Spicula with a filiform appendage at one extremity.
l. Spicula without the filiform appendage.

JOURNAL OF MICROSCOPICAL SCIENCE,

ZOOPHY TOLOGY.

Description of Figures.

PLATE I.
Fig.
1.—Salicornaria borealis (natural size.)
2.—The same, magnified about 40 diam.
3.—The same, magnified abont 80 diam.
4,—Menipea arctica, magnified about 40 diam.
5.—Front view of a cell, with avicularium, magnified 80 diam.
6.—Back view of part of a branch, magnified about 80 diam.
7.—Membranipora Sophice, magnified 80 diam. ;

PLATE II.

1.—Lepralia scutulata, magnified 40 diam.

2.—The same, magnified 80 diam.

3.—Tubulipora ventiicosa, magnified 40 diam.
4.—Extremities of two tubes magnified about 80 diam.
5,—Sertularia polyzonias ? (natural size.)

6,—The same, magnified about 40 diam.
7.—Sertularia imbricata (natural size.)

8.—The same, magnified about 40 diam.

9.—The same, magnified about 80 diam.

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JOURNAL OF MICROSCOPICAL SCIENCE.

DESCRIPTION OF PLATE XI.

Illustrating Mr. Rainey’s paper on the Structure of the
Cutaneous Follicles of the Toad.

Fig.
1.—Skin of toad injected, showing cutaneous capillaries.
2,—Opposite side of the same piece of skin, showing one of the cutaneous

follicles.
3.—A vertical section of the skin, showing some follicles cut perpendi-

cular to the surface.
a. One cut at its middle, where it communicates with the

surface.
b. b. Follicles cut on one side of their centre.
c. A layer of earthy matter lying over the follicle, between it

and the surface.
These three are magnified 20 diameters.
4,—Horizontal section of a follicle, showing the folds of internal mem-

brane.
a. The layer of capillaries.
b. Internal membrane.
ce. Epithelium covering the follicles of the internal membrane.
Magnified 50 diameters.
5,—A. Deep portion of the epidermis, showing the form of the epidermic

scales, and the clear, homogeneous nuclei.
B. Epithelium of a cutaneous follicle, showing the character of the
epithelic cells and the granular nuclei, with some of the

eranular contents of the follicle.
Magnified 300 diameters.

DESCRIPTION OF PLATE XII.

Illustrating Mr. Currey’s paper on the reproductive organs of
Fungi.
Fig.
1.—A perithecium of the spheropsoid form of Spheria herbarum with
its mycelium, attached to a fragment of the cuticle of a dead stem
of Senecio Jacobeea, magnified about 110 diameters.

2.—Transverse section (magnified 110 diameters) of a similar perithecium,
_showing the spermatia in its interior. .The knotty mycelium is
still attached. ae ee
3.—Reproductive gemma, or conidia, which grow directly from the
mycelium of Spheria herbarum, magnified 220 diameters.

4.—An ascus and sporidia of Spheria herbarum. The sporidia have
germinated in the interior of the ascus, and have broken through
the membrane. Magnified 220 diameters.

5 and 6.—Germinating sporidia of Spheria herbarum. In fig. 5 are seen
globular vesicles at the extremity of short lateral branches. Mag-
nified 220 diameters. -

7.—Fragment of a germ-filament of a sporidium of Spheria herbarum.
At the extremity of a short lateral branch a nucleus has been
formed, and a fresh germ-filament thrown out.

8.—A germinating sporidium of Spheeria herbarwm, showing the forma-
tion of a lateral bud similar to those shown in fig. 3. Magnified
220 diameters. :

9.—Asci and sporidia of Spheria herbarum, magnified 220 diameters.

10.—Ascus and sporidia of Spheeria (complanata ?), magnified 220 dia-
meters.

11.—One out of a number of similar bodies found in the interior of the
perithecia of Spheria complanata, magnified 220 diameters.

12.—Young states of asci of Spheeria Cryptosporii, magnified 220 diameters.

13.—(a), perfect asci, with sporidia of Spheria Cryptosporii. (b), a spo-
ridium from one of the asci. (c), a very young ascus. (d), an
ascus rather more advanced. (e), the most common form of spore
of Cryptosporium vulgare. (f), another form of spore of the
same plant. All magnified 220 diameters,

14.—Asci and sporidia of Spheria found growing with Cryptosporium
vulgare, magnified 220 diameters.

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JOURNAL OF MICROSCOPICAL SCIENCE.

PLATES XIII. anp XIV.

Figures illustrating Mr. J. Glaisher’s Paper on Snow

Crystals.

Figs, 14 and 19 are not referred to in the paper: on these Mr, Glaisher
adds the following notes :—

Fie. 14,—On February 8th, the mean reading of the barometer at the
height of 82 feet above the sea was 29°730 inches: the highest reading of
the thermometer during the day was 32°, the lowest was 274°, and the
mean temperature for the whole day was 30°, being 8° below the average
of the same day. The temperature of the dew point was 29°. Snow was
falling the whole of the day, with scarcely any intermission.

Fie. 19.—On February 17th, the mean reading of the barometer at the
height of 82 feet was 29°880 inches: the highest reading of the ther-
mometer during the day was 334°, the lowest was 22°, and the mean for
the whole day was 253”, being 133° below the average for the day. The
mean temperature of the dew point was 193°. The sky was overcast till

noon, and snow was falling occasionally.

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DESCRIPTION OF FIGURES.

PuateE III.
Fig.
1.—Portion of polyzoary of Onchopora hirsuta in the younger condition.
2.—Ditto, older.
3, 4, 5.—Disposition of the cells at an articulation.

6.—Natural size.

Puate IV.

1.—Portion of polyzoary of Onchopora tubulosa.

1 (a).—Natural size.

2, 3.—O. mutica.

3 (a).—Natural size.

4.—Eschara cervicornis? in the younger part of the polyzoary.
5.—An older portion.

6.—One still older, in which the cells are quite immersed.
7.—Natural size.

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