PLANT-EATING MAMMALS 165 



sharply-pointed cheek-teeth as in insect-eating forms; but these 

 negative features are not so conclusive as the positive indication 

 of plant-eating habit afforded by the stomach, which, instead of 

 being a simple sac as in man and most monkeys, is complex, 

 consisting of three separate divisions. Vegetarian mammals, 

 notably the ruminating forms, commonly possess a complex 

 arrangement of the sort. Reasoning from analogy, Owen, after 

 studying the anatomy of monkeys of this group, put them down 

 as leaf -eaters at a time when the nature of their food was 

 a matter of conjecture. Subsequent observation proved the 

 correctness of this surmise, as Entellus Monkeys and their kind 

 feed largely on leaves and juicy shoots. 



HOOFED MAMMALS (UNGULATA) 



The majority of the animals included in the large and im- 

 portant order of UNGULATA are characteristically vegetable-feeders, 

 though the omnivorous pigs and their allies form an important 

 exception to this. It may be remembered that there are two 

 sub-orders of Ungulates (see vol. i, p. 104) (i) the odd-toed forms 

 or Perissodactyles, including Tapirs, Rhinoceroses, and Horses; 

 and (2) the even-toed species or Artiodactyles, including the 

 non-ruminating groups of Swine and Hippopotami, and the 

 ruminating animals embraced under the headings of Deer, 

 Antelopes, Cattle, and Giraffes. It will suffice for the present 

 purpose to devote most of our space to considering in detail the 

 food and feeding of the Horse and Ox, highly specialized repre- 

 sentatives of the two sub-orders. The points specially deserving 

 consideration will be the means employed in securing food 

 (prehension), and afterwards reducing it to a fit state for absorp- 

 tion into the blood and lymph. 



The Horse (Equus cabalhis], like most grazing animals, spends 

 a large part of its time with the head bent down to the ground, 

 and if the raising of it, which is constantly necessary, were brought 

 about by muscular action solely, a wasteful amount of force would 

 be expended. But in such cases the greater part of the work is 

 done by the elasticity of a strong neck-ligament, which runs from 

 the back of the skull to the long spines of the chest vertebrae, and 

 sends branches forwards to be attached to the joints of the neck. 

 Herbage is gathered into the mouth by the agency of the lips, 

 which are extremely sensitive and flexible. Regarding them, 



