216 



MR. J. B. SUTTON ON DISKASES IN MAMMALS. [Apr. 20, 



carrying with it, the ileo-csecal 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. 



The inarsupium of a Short-beadecl Plialanger, Bfluhus hreviceps, opened in 

 order to show a scirrhous cancer growing from the mammary gland. 



The microscopic characters of the growth are shown in iigure B. 



is most frequency affected in this way in the human subject; but 

 it is au example of the rarer form that occurs in this situation, viz. 

 the ileo-csecal 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 

 azarcB 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 



