1881.] NATURAL SCIENCES OF PHILADELPHIA. 145 



appearance and size of the corpus striatum, .s, taenia, thalamus 

 opticus, 0, and hippocampus major, when compared side b}^ side 

 with the corresponding parts of the Manatee, resembled these 

 more than the}' did those of the Giraffe, Llama, Peccar3\ etc. Of 

 the corpora quadrigemina in the Hippopotamus, the testes, ^, 

 were broader than the nates, n, and less rounded in shape. ^ 



If the above description of the brain of the Hippopotamus be 

 correct, it follows that the general form of its hemispheres, the 

 arrangement of its fissures, etc., deviate but little from the t3'pical 

 ungulate brain, while the capaciousness of its ventricles, the form 

 of its basal ganglia, and the cerebellum, resemble rather those of 

 the brain of the Manatee. 



Sweat Glands. — As is well known, when the Hippopotamus 

 comes out of the water there exudes from tlie slcin a pinkish, 

 reddish secretion, which quicldy dries up and does not reappear 

 until the animal comes out of the water again. This secretion 

 has probably given rise to the name blood-sweating Behemoth, 

 bj'^ wliich the Hippopotamus is often known among showmen. 

 This secretion was first examined by Tomes, ^ who stated that it 

 consisted of a transparent fluid containing colorless and red- 

 colored corpuscles, the color of the secretion being due to the 

 solution of the latter. Crisp ^ examined and figured the glands 

 supposed to produce this secretion. It will be remembered that 

 his specimen was burnt to death, and it was to be expected, there- 

 fore, that the skin was affected. For this reason I requested that 

 admirable microscopist, Dr. J. Gibbons Hunt, to examine the skin 

 of my Hippopotamus, and I give his result in his own words : 



" I put in a camera lucida slietch of the blood-gland (fig. 4) 

 of the Hippopotamus magnified 25 diameters. It has no limiting 

 membrane, but bioplasts or nuclei of the usual apparent form 

 make up the entire gland. In the centre these gland-cells are loosely 

 arranged, thus allowing the contents to escape, perhaps, like com- 

 mon sweat glands do, in which, similarly, there is no external or 

 internal membrane." 



The contents of the gland-cells loosel}' arranged in tiie centre 

 are probabl}" the corpuscle, the solution of which, according to 



^ Peters gives in Moiiatsberichte of Berlin Acad., 1854, a brief description 

 of the brain of the Hippopotamus, but unfortunately not ilhistrated. 

 2 Proc. Zool. Soc. of London, 1850. 

 ■^ Op. cit., p. 603. 

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