164 



COMPARATIVE ZOOLOGY. 



FIG. 128. Feet of Carnivores : A, Plantigrade (Bear); B, Pinnigrade (Seal): C, 

 Digitigrade (Lion). 



some may be wanting, so that we have one-toed animals 

 (as Horse), two-toed (as Ox), three-toed (as Ehinoceros), 

 four-toed (as Hippopotamus), and five-toed (as the Ele- 

 phant). The Horse steps on what corresponds to the nail 

 of the middle finger ; and its swiftness is conditioned on 

 the solidity of the extremities of the limbs. Horses of 

 the greatest speed have the shoulder-joints directed at a 

 considerable angle with the arm. 



Pie. 129. Feet of Hoofed Mammals: A, Elephant; B, Hippopotamus; C, Rhinoc- 

 eros; D, Ox; E, Horse, a, astragalus: cl, calcaneum, or heel ; s, uaviculare; 6, 

 cuboides ; ct, ci, cm, cuneiform bones ; the numbers indicate the digits in use. 



