362 THE ANATOMY OF VEETEBEATED ANIMALS. 



the tarsus tas the ordinary seven bones. The pulley of the 

 astragalus is not very deeply grooved, and is hardly at all 

 oblique. The facet for the cuboid is very small. The 

 metatarsals resemble the metacarpals in their number and 

 symmetry, but there is no rudiment of the fifth. 



In some species of Rhinoceros there are ^ incisors in the 

 milk dentition, and ^rrx 01^ t-t incisors in the permanent 



2*2 1*1 



dentition. In the latter the upper incisors are large, 

 long-crowned teeth, very unlike the lower ones, of which 

 it seems probable that only one pair, in any case, are 

 permanent teeth. In some Rhinoceroses, as has been 

 already stated, the adult is devoid of incisor teeth. 



There are no canines in either dentition. Of the 

 four milk molars, the first, as in the Horse, is smaller than 

 the others, and is not replaced. The structure of both the 

 upper and the lower molars is substantially the same as in 

 the Horse, but the roots are developed much sooner; 

 the laminae of the upper molars take a much more trans- 

 verse direction; the laminae of the upper molars do not 

 develop pillars, though accessory crests may be developed 

 from the two faces of the posterior lamina; the lower 

 molars have no pillars ; and the cement does not fill up 

 the valleys between the wall and the laminae. 



The cardiac division of the simple, though large, stomach 

 is lined by a white callous epithelium, as in the Horse. The 

 small intestine presents large processes or tags, haK an inch 

 long or more, upon which the true viUi are borne. The 

 caecum is very large, and the colon enormous. There is no 

 gall-bladder. The heart and brain are very similar to 

 those of the Horse. 



The male can hardly be said to have a scrotum, as the 

 testes lie close to the abdominal ring. A prostate, vesiculae 

 seminales, and Cowper's glands are present. The long penis 

 has a mushroom-shaped glans, and the animal is retro- 

 mingent. The cornua uteri are proportionately longer than 

 in the mare. The teats are two and inguinal in position. 



