196 



TYPES OF ANIMAL LIFE 



in the structure of their feet. In the first place, the 

 hind-foot has three digits, yet this does not make it 

 an odd-toed ungulate, because only two are functional 

 and the line of symmetry passes down between them, as 

 in the other even-toed hoofed beasts. The fore-foot is as 

 in the swine. The other exceptional character is the 

 median union of the upper portions of the two middle- 

 foot bones into a single solid structure or cannon bone. 

 This union exists in all the ruminants except the African 



Fig. 54, 



THE COLLARED PECCARY. 



water chevrotain. The camels and llamas have but two 

 toes to each foot, but the other ruminants have generally 

 the two lateral digits more or less represented. In the 

 bison there are only minute representations of the two 

 lateral digits, with the addition, in each fore foot, of a 

 short rudiment of each corresponding middle-hand 

 bone, but quite separate from the digits to which they 

 correspond. 



Beasts in general have, like ourselves, three kinds of 

 teeth — cutting teeth, in front ; eye teeth, called canines 



