216 MR. J.B. SUTTON ON DISEASES IN MAMMALS. [Apr. 20, 
carrying with it, the ileo-czecal valve (see fig. 9, p.217). The 
invaginated portion measures two and a half inches. The portion 
of gut above the constricted portion was very congested and almost 
gangrenous. ‘The intussusception was very acute, and probably killed 
the animal, a Lemur, very quickly. The case is further interesting, 
for the intussusception occurred at that part of the intestine which 
Fig. 8. 
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2 
Ay 
2, 
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4 
mr 
The marsupium of a Short-headed Phalanger, Belideus breviceps, opened 
order to show a scirrhous cancer growing from the mammary gland. 
n 
The microscopic characters of the growth are shown in figure B. 
is most frequently affected in this way in the human subject; but 
it is an example of the rarer form that occurs in this situation, viz. 
the ileo-czecal variety. 
The investigation into disease, structural aberrations, and mal- 
formations of animals is of considerable importance apart from its 
intrinsic interest. Darwin, in his ‘ Descent of Man,’ 2nd ed., 1874, 
page 6, writes :—‘ Man is liable to receive from the lower animals, 
and to communicate to them, certain diseases, as hydrophobia, 
variola, glanders, syphilis, cholera, herpes, etc. ; and this fact proves 
the close similarity of their tissues and blood, both in minute 
structure and composition, far more plainly than does their com- 
parison under the best microscope or by the aid of the best chemical 
analysis.” He then quotes Rengger to the effect that the Cebus 
azare in its native land is liable to catarrh, apoplexy, inflammation 
of the bowels, and cataract. 
This quotation seems to indicate beyond doubt that, had sufficient 
evidence been forthcoming regarding diseases of animals, Darwin 
