116 ELEMENTS OF COMPARATIVE ZOOLOGY. 



To the perissodactyls belong, of living forms, the tapirs, 

 rhinoceroses, and horses. The tapirs live in the forest 

 regions of the tropics of both continents. They have a 

 hog-like body, large prehensile upper lip; teeth, i |, c \, pm 

 j, m |; while their fore feet have four toes, the hind feet 

 three. Yet, although the fore feet have an even number 

 of toes, these are not symmetrically arranged, as in artio- 

 dactyl forms, the pig for example, but one (third) is en- 

 larged and bears most of the weight of the body. 



The rhinoceroses have three toes on each foot; the skin 



FIG. 48. Sumatran rhinoceros (Ceratorhinus sumatrensis) . From Liitken. 



is extremely thick; the snout bears one or two well- 

 developed horns, in which there is no bony core; and 

 canine teeth are not developed even in the young. There 

 are six species known, those occurring in Africa having 

 two horns, while in the East Indies are both one and two- 

 horned forms. 



In the horses the reduction of toes has gone still farther, 



