-+> Fauna : Mammals 



reference to the structure of their molar teeth or the specialisa- 

 tion of their stomachs connected with the re-chewing of food. 

 In the Chevrotains, the stomach is less specialised than the 

 digestive apparatus of the Pecora and Camels, having but 

 three (instead of four) separate 

 compartments. Although the mo- 

 lar teeth of the chevrotains are 

 selenodont that is to say, with 

 a grinding surface crumpled into 

 crescentic folds the foremost of 

 the premolars (as may be seen 

 from my illustration of the skull) 

 are narrow teeth with quite a sharp 

 cutting-edge, a more primitive 

 feature than can be met with in 

 the Deer, Giraffes, Cattle, and 

 Antelopes. The Chevrotains also 

 offer more generalised charac- 

 teristics in regard to the placenta. 



But perhaps the most in- 

 teresting feature in these little 

 animals is the structure of the 

 limbs. Any one glancing at the 

 skeleton of a cow or sheep will 

 notice that in the fore and hind 

 limbs the bones between the wrist 

 and heel joints and the knuckles 



or instep are fused into a single long bone, instead of being as 

 many in number as the functional toes. The ox, for example, 

 is a two-toed animal, walking on what would be equivalent in 

 us to the third and fourth fingers (counting the thumb as the 

 first finger). But the bones that are called the metacarpal and 



723 



281. HIND-LEG OF WATER CHEVROTAIN 



