Oct. 8, 1885 | 
NATURE 
561 
A specimen was shown of a two-toed horse. The valuable 
researches of Prof. Marsh on the descent of the horse were 
specially alluded to. Dr. Stiuthers demonstrated another fact 
connected with the development of the foot of the hors:—that 
the first phalanx, or pastern bone, has an epiphysis at both ends. 
‘On the Viscera of Gymnotus electricus, by Prof. Cleland.— 
Independent of its electric organs, this fish has a number of 
remarkable internal peculiarities. The curious spongy protuber- 
ances of the mucous membrane of the buccal cavity are well 
known to zoologists. The two swimming-bladders are remark- 
able for their relation to the kidneys; the anterior swimming- 
bladder being a small structure between their anterior extremities, 
and the larger posterior swimming-bladder being situated alto- 
gether behind their under hinder ends, while the duct of the 
latter ascends by the left side of the renal outlet, to be joined 
by the duct of the other bladder before entering the gullet. The 
pylorus also is remarkably contracted. But the most striking 
and altogether curious arrangements are seen on the ventral wall 
ofthe abdomen. The intestine passes forward the whole length 
of the abdominal cavity to the vent, and on its under side is a 
long renal duct as wide as itself, and opening immediately 
behind the vent ; while, opening into this duct close to its out- 
let, are the ducts of the two ovaries, which lie one on each side, 
their morphologically anterior extremities placed posteriorly, as 
if in process of development these organs had been pulled 
around from their proper sub-vertebral position until completely 
inverted. 
The Spiracle of Fishes in its relation to the Head, as devel- 
oped in the Higher Vertebrates, by Prof. Cleland.—A very 
extraordinary mistake can be shown to be prevalent among 
embryologists, to the effect that the spiracle corresponds with 
the tympanum and external auditory meatus in the higher verte- 
brates. This is not the case. The spiracle is pre-oral; the 
tympanum is post-oral. The apparent sequence of the spiracle 
with the branchial clefts occurs, as Balfour described it, in the 
embryo of the dog-fish; but for all that, and although it has 
rudimentary external gills attached to its margins in the embryo, 
it is in front of the mandibular arch and above the maxillary 
lobe. Between the middle and lateral frontal processes is the 
nostril ; between the lateral frontal process and the mandible is 
the space into the upper part of which the eyebal! projects, and 
from which the lachrymal duct is developed ; while between the 
first and second visceral lobes is the external ear; and it is 
highly probable that the upper part of the first branchial cleft is 
homologous with the clefts in front of and behind the lateral 
frontal process. Thus a certain amount of homology would 
exist between the spiracle of fishes and the lachrymal duct. 
Ls the Commissural Theory of the Corpus Callosum Correct ? 
by D. J. Hamilton, M.B., Professor of Pathological Anatomy, 
Aberdeen University.—The results recorded by the author were 
obtained by certain special methods of preparation. They 
went to prove that the corpus callosum is not an inter-hemi- 
spherical commissure, as is generally supposed, but that it is in 
reality the decussation of a particular system of fibres on their 
way downwards to join the inner and outer capsules. These 
fibres are not to be confounded with the motor and other direct 
fibres derived from the cerebral cortex, and which decussate at 
some point lower down. 
The Evirence of Comparative Anatomy with regard to 
Localisation of Function in the Cortex of the Brain, by Alex. 
Hill, M.A., M.B. Cambridge.—The object of the paper was 
to show that the theory of the localisation of function in the 
cortex of the brain must be submitted eventually to comparative 
anatomy for proof. The key to the arrangement of the lower 
parts of the central nervous system is to be found, as the author 
had elsewhere shown, in its segmental disposition: the grey 
matter is disposed in clumps the cells of which bear a definite 
numerical relation to the fibres of body nerves. The problem 
discussed in the present paper was the relation of the grey 
matter of the cortex to this lower grey matter, and therefore to 
the body nerves. Is each region of the cortex equally in rela- 
tion with all the segments of the ‘‘ central grey tube”? or is 
the cortex also divided up into areas, the superficies of each of 
which varies as the amount of grey matter in the clump of the 
lower system with which it is related, and therefore as the 
number of fibres in its associated nerve. For this investigation 
guides to the delimitation of the cortex are necessary, and no 
others are available for the purpose if the fissures fail. The 
homological value of the fissures is, however, established by the 
study of adult and foetal brains. They are remarkably constant 
in their arrangement throughout animals of the same type, and 
in animals of different type they are very constant with regard 
to the order of their appearance, their progressive extension and 
permanent depth. The author of the paper expressed himself 
content, on account of the precision with which the fissures 
respond to the ordinary tests of homology, to place himself un- 
conditionally in their hands, and the boundaries of the various 
regions of the cortex being thus marked out, it remains to devise 
a system of mensuration by which the superficial area of each 
region of the cortex may be determined for comparison with the 
cross-sections of the several nerves. As yet no satisfactory 
method of measurement has been devised, but even in the 
absence of exact data important results'can be obtained by the 
observation of the brains of such animals as are conspicuous for 
excess or deficiency in the development of the muscular system 
or of one or more of the senses. As examples of such results 
Mr. Hill exhibited diagrams of the braiis of the sheep, cat, pig, 
dog, and otter, enlarged from tracings of the pictures in Leuret 
and Gratiolet’s Atlas. It was shown that, although it is im- 
possible, as yet, to map out the brain into areas associated with 
the several nerves, it is quite possible to predict from the appear- 
ance of the brain the principal sensory and motor endowments 
of the animal to which it belonged. In the main Mr. Hill’s 
results confirm those already obtained by Ferrier and other 
experimental physiologists ; they seem, however, to show that 
they are open to correction in certain important points with 
regard to the areas allocated to the senses of smell, hearing, and 
facial sensation. 
The Action of Cold on Microphytes.—Prof. M ‘Kendrick, 
Glasgow. gave an interesting account of the methods of trying 
to destroy small organisms like bacteria, not as is commonly 
done by heat, but by cold. It is known that by means of 
Coleman’s cooling machine meat may be kept from putrefying 
for a considerable time, but in attempting to sterilise a putrescible 
solution by means of cold, it was found that, though in some 
cases putrescence was delayed, in no case were the organisms 
completely destroyed. Organic fluids were exposed to tempera- 
tures more than 120° below o° F., but on thawing they were 
found to contain living organisms still. Thus the hope of pre- 
serving putrescible matter by means of cold—an important 
economical result—is, so far as investigation yet goes, destroyed. 
The organisms under cold seem to be in a nearly solid state, 
though we cannot call it a crystalline state. In a paste solution 
the water is crystallised under cold, the paste remaining spongy. 
Possibly cold may separate from these minute organisms the 
water they contain, and this water is again absorbed on thawing. 
Meat under cold becomes very friable, while yet minute frag- 
ments of it show the same microscopic constitution of muscle. 
It is well known that frogs have been found in blocks of ice 
and been revived. Frogs have been frozen at 20° F. in about 
half an hour. On thawing slowly the animal, in two instances, 
completely recovered. When it was frozen for longer than half 
an hour it did not recover ; but, though reflex action was gone, 
there remained some irritability both in nerves and muscles. It 
was found also that certain vital functions may be arrested by 
cold, and thus conceivably higher organisms may be kept vitally 
inert for an indefinite time. Experiments were also tried on 
warm-blooded animals. A rabbit subjected to a temperature 
100° below 0° F, recovered. No temperature lower than 73° 
below o°? F. has been obtained in free atmosphere. Prof. 
M‘Kendrick gave a short sketch of the literature of the subject. 
The Action of Ozonised Air upon Micro-Organisms and 
Albumen in Solution, by J. J Coleman, F.1.C., F.C.S.—This 
paper described a number of experiments conducted by the 
author in conjunction with Prof. McKendrick, F.R.S., being 
supplementary to their joint investigation upon the influence of 
cold on microphytes. Air artificially impregnated with ozone 
by means of a Ruhmkorff coil, so as to contain a much larger 
percentage of ozone than any natural atmospheric air, was passed 
continuously through a 1 per cent. solution of white of egg 
placed in a glass flask, the inlet and outlet tubes of which were 
carefully plugged with cotton wool previously to commencing 
the experiment. It was found that a stream of air containing an 
amount of ozone equal in weight to the albumen in solution 
passed through 100 c.c. of the liquid for thirty hours, failed in 
producing the slightest trace of oxidation, and that the ozonised 
air passed through the liquid quite unaltered. During the course 
of the experiment and for six days following the development of 
micro-organisms ceased, but at the end of that time, and not- 
withstanding the cotton wool plugs, the liquid became slightly 
