324 



NATURAL HISTORY. 



species (Rhinoceros tichorhinus}, though that the latter had great horns is proved by the nature of the 



bones of the nose and face which supported their weight. The Sumatran bicorn Rhinoceros combines, 

 with comparatively small horns, moderately developed incisors in both jaws. 



The sternum of the mature animal consists of four bones, the first of 

 which is compressed into a ploughshare-like shape, and projects in a point in 

 front of the first rib. All the bones of the fore limbs of the Rhinoceros 

 resemble those of the Tapir more than those of any other animal ; but 

 from their much larger size are not at all likely to be confounded with 

 them. Of the hind limbs, the points offering peculiarities are as follows : 

 The femur is remarkable for being extremely flattened from before backwards, 

 and the projection called by Cuvier the third trochanter projects very much, 

 forming a hook ascending towards a hook which descends from the projec- 

 tion known as the grand trochanter, thereby leaving an oval hole between 

 these two projections. With regard to the lower portions of the hind leg, 

 resemblances are to be found both to the Horse and Tapir, the tibia, fibula, 

 and tarsus being built on the same plan as those of the former, although 

 some of the bones of the tai*sus resemble those of the Tapir more than 

 they do those of the Horse. There are also some points of resemblance in 

 the metatarsus to that of both the Horse and Tapir. The difference 

 between the hind legs of the Rhinoceros and Elephant is very marked, and 

 their gait is different. 



The dentition of the Rhinoceros differs in a very remarkable degree 



from that of the family of Horses. The grinders . i 



are implanted by distinct roots, and in the upper 



jaw their crowns are traversed by two deep folds of 



enamel, which constitute open valleys. In the lower 



jaw they are composed of two crescent-shaped lobes, also 



open. The covering of " cement" is thin, and never 



fills up the valleys, as in the case of the more complex 



dental system in tho Horse. The normal number of the 



grinders is seven in each jaw, while the incisors, as we 



have already remarked, vary, not only in form, but also 



are sometimes absent, and canines are not developed in 



any of the living or fossil members of the family. 



FEMtUI Of KHINOCEKOS. 



THE AFRICAN EHINOCEROSES. 



Of the number of species of Rhinoceros there is con- 

 sidei-able doubt. At least four, possibly five, inhabit 

 Africa, and four Asia. With regard to the African 

 species, we will first take the large " WHITE " RHINOCEROS 

 (Rhinoceros simus) described by Burchell. This is an 

 animal measuring somewhat over twelve feet in length 

 and about five feet ten inches in height. It has a square 

 nose and two large rounded horns, the anterior one 

 averaging about two feet six inches in length, but not 

 uncommonly found measuring three feet six inches, 

 sometimes even over four feet ; the posterior rarely or 

 never exceeding fifteen inches, and generally not being 

 more than twelve inches. Its skin is smooth, and without any of those folds so characteristic of 

 the Asiatic species. It inhabits all the country south of the Zambesi, and probably it may also 

 exist in Central Africa. It feeds solely on grass, and sometimes collects into small herds. 



OSWELL'S RHINOCEROS* in no way differs from R. simics, except that the front horn points 



* Rhinoceros Oswdlii. 



DENTITION OF RHINOCEROS. A, UPPER ; 

 B, LOWER JAW. 



