of the ordinary Hippopotamus amphibius, which died during the 

 year past in this country. He figures the brain, alimentary and 

 reproductive systems, and adds much of importance to our 

 knowledge of this great beast. In conclusion, he thus remarks 

 on the natural affinities of the hippopotamus with the Ungulata 

 and other mammals, especially the manatee. " In observing the 

 manatee that lived for several months in the Philadelphia Zo61og- 

 lcal Garden, the manner in which it rose to the surface of the 

 water to breathe reminded me often of the hippopotami that I 

 watched in the Zoological Garden of London and the Jardin des 

 Plantes in Paris. The slow way in which the animals rise to the 

 surface, the motionless pose of the almost sunken body, the nos- 

 trils often just appearing at the surface, etc., are very much alike 

 in both animals. In speaking of the alimentary canal, I called 

 attention to the stomach of the manatee, which represents that of 

 the hippopotamus in an atrophied condition, while, on the other 

 hand, the stomach of the hippopotamus is intermediate between 

 the peccary and the ruminants. As regards the heart it will be 

 remembered that in the young hippopotamus, at least, it is bifid, 

 ' - itib] n - in this respect that of the manatee. The female gen- 

 erative apparatus of the peccary and hippopotamus are almost 

 identical. Again, the sexual vesicles are found in both hippopot- 

 amus and manatee. While the placenta does not appear to me 

 to have the importance attached to it bv some authors as a guide 

 in determining the affinities of animals', it is proper to mention in 

 this connection that according to Milne Edwards and Garrod the 

 placenta of the hippopotamus is diffuse, and appears to be non- 

 deciduous, and such is the case, according to Harting, in the 

 dugong, and therefore in the manatee, probably, for, as a matter 

 of fact, the placentation of the manatee is unknown. 



" While the brain of the hippopotamus appears to be a modifi- 

 cation of a type common to the pig, peccary, sheep, ox, giraffe, 

 etc., it has also, it seems to me, affinities with that of the manatee 

 In a word, then, beginning with the pig, we pass by an easy 

 transition to the peccary, which leads to the hippopotamus and 

 thence, in diverging lines, to the Ruminantia on the one hand, and 

 the manatee on the other. Palaeontologists have not discovered a 

 form which bridges over the gap between the hippopotamus and 

 the manatee, but it will be remembered that certain fossil bones, 

 considered by Cuvier to have belonged to an extinct species of 

 hippopotamus, //. medius, are regarded by Gervais as the remains 

 >! th • Ifalithcn tm fossiL; m extinct Sirenian, of which order the 

 manatee is a , According to Professor Owen, 



the molar teeth also, both in the Halil Inotherium, 



another Si reman, are constructed on the same pattern as those of 

 the hippopotamus. It is proper to mention, however, that the 

 same distinguished observer considers the teeth of the manatee 

 and the Prorastomus, another extinct Sirenian, to be rather allied 



