252 



FIRST LESSONS IN ZOOLOGY. 



hence they do not grow out. In the horse, which nibbles 

 the grass, sharp chisel-like incisors are needed both in the 

 upper and lower jaw. Moreover, feeding only on grass or 

 leaves, the flesh or canine teeth are not needed, and they 

 are absent; but the molars are square and flat-topped for 

 crushing their food. In all important respects, then, the 

 hoofed animals are perfectly adapted to their surroundings. 

 Being weak and unprotected, they go in herds, and, as in 

 horses, asses, oxen, or buffaloes, they have self-appointed 

 leaders. Horses, deer, and oxen are timid, nervous crea- 

 tures, and a single bear, panther or lion, will put a herd of 

 them to flight. Hence it is necessary that there should be a 

 great number of individuals, and so it has come to pass that 

 the type of hoofed mammals has been very successful in 

 point of numbers, the order being only less numerous in 

 species than the rodents, and perhaps greatly exceeding 

 ^ ^ them in numbers of individuals. 



And so have resulted the greal 

 herds of horses and sheep, anc 

 the droves of cattle necessary t( 

 doing that work in the world 

 which it was destined for man to 

 undertake. We could do without 

 rats, mice, and other rodent ver- 

 min; but what could we do with- 

 out beasts of burden, and hoofed 

 beasts to afEord us beef, pork, 

 and mutton? 



Hoofed Mammals ivith Odd 

 Toes. — To this group belong the 

 tapir, rhinoceros, and horse. Of 

 these the most interesting, from 

 a scientific point of view, are the 

 tapir and the horse. Put them 

 side by side, and how unlike they 

 are ! The tapir is short-legged, uncouth, and clumsy in 

 figure, its snout almost proboscis-like, and the feet end ia 



'met 



Fig. 250.— a, fore foot of Tapir; 

 B, of Horse, u, ulna; r, radius; 

 p, pisiform bone; c, centrale; sZ, 

 semi-limar; sc, scaphoid; u, unci- 

 form; cp, capitatum; tr^ trape- 

 zoid; met, metacarpus; 2, 3, 4, 5, 

 8d, 3d, 4tli, andBth digits. 



