THE HIPPOPOTAMI 



1031 



neck from the strain of its weight. The portion of the skull iff^ front of the eyes is 

 very much longer than that behind them, and the sockets of the eyes (as seen incur 

 gure of the skeleton) are completely surrrounded by a very prominent bony ring, 

 which has an almost tubular form. In the pigs, on the other hand, the socket of 

 the eye is open behind (compare the figure on p. 1009). The prominence of these 

 sockets causes the relatively-small eyes of the hippopotamus to project far above the 

 level of the forehead. The ears are small and rounded, and the slit-like nostrils are 

 placed rather close together on the highest point of the broad, bristly muzzle; while 

 both ears and nostrils alike can be completely closed at the will of the animal. The 

 neck is extremely short and powerful; and the body is so deep, that when the ani- 

 mal is walking on soft mud, the under surface comes in contact with the ground. 

 Disproportionately short for the size of the animal, the tail is laterally compressed 

 from side to side. The short and broad feet are furnished with four well-developed 

 short toes, all of which touch the ground when walking; and are incased in rounded 

 black hoofs, of which the middle pair have not their inner surfaces flattened, so that 



SKELETON OF HIPPOPOTAMUS. 



the hippopotamus lacks the cloven hoof of the pigs and the Ruminants. The toes 

 of the feet are partially connected by webs. Although there are a number of bris- 

 tles on the muzzle, and also a few on the sides of the head and neck, as well as at 

 the extremity of the tail, the skin of the hippopotamus is naked; it is also rather 

 rough and warty, and of enormous thickness. 



The gigantic mouth of a hippopotamus, when opened to the widest, is one of 

 the ugliest sights imaginable, looking like a huge red cavern, from the edges of 

 which project the enormous tusks and incisor teeth. The tusks, or canines, are the 

 largest of the teeth in the jaws, and are curved backward in a bold sweep, with 

 their extremities obliquely beveled off by mutual attrition; they grow throughout 

 the life of the animal, and their points are directed downward. The incisor teeth 

 likewise grow during the whole period of existence, and thereby differ from those of 

 the pigs, which form roots. In the existing species, there are not more than two 

 pairs of these teeth, and whereas those of the upper jaw are directed downward, 

 the lower ones project forward in advance of the jaw. The sides of the jaws are 



