200 PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



organism from that of the carnivora. Even in such a typical group of 

 herbivorous animals as the ruminants we find that in them, when new- 

 born, the complex stomach is rudimentary and their alimentary canal 

 differs but little from that of the carnivora, simply foreshadowing what 

 will ultimately be developed when the animals are placed upon a purely 

 herbivorous diet. Among the carnivora the most typical examples will 

 sometimes refuse vegetable nourishment, and the tiger and lion and the 

 eagle have been known to die of starvation rather than touch it ; never- 

 theless, an eagle has been educated to eat and digest bread. The native 

 repugnance to certain foods is often overcome by cooking, and it is with- 

 out doubt to this circumstance that man is omnivorous in character. 

 Thus, dogs and cats do not eat corn, but they will eat bread. This is, 

 however, in all probability to be explained by the fact that the uncrushed 

 seeds are incapable of digestion by carnivorous animals, since their 

 organs of mastication do not permit of the liberation of the nutritive 

 principles from their undigestible envelopes. Cooking, nevertheless, does 

 lead many animals to eat food which is unnatural to their species ; thus, 

 the rabbit will refuse raw meat, but will often willingly accept and digest 

 boiled meat. Certain animals are both carnivorous and herbivorous. 

 This is especially illustrated among the birds, where some are fructivorous 

 in winter and insectivorous in summer ; so the small fructivorous monkey 

 will eat insects and seek for eggs and little birds scarcely hatched. Even in 

 the same groups of animals some are carnivorous and some herbivorous; 

 thus, among plantigrades and the cetaceans we have examples of each. 

 It is worthy of notice, however, that when forcing the diet is arrested 

 and animals are restored to their native state, they will again return to 

 their natural food. The herbivora forming the food of the carnivora, 

 and feeding themselves on vegetable matters for the maintenance of 

 their species, must consequently be in excess of the carnivora. 



We thus see that the choice of food is controlled by the animal's 

 habits and appetites. Herbivorous quadrupeds graze and consume 

 grasses, bulbs, and grains suitable to the organs of their digestive 

 apparatus, while the carnivora devour the flesh of the herbivora, and 

 show aversion to the carcasses of animals allied to themselves in their 

 habits. An artificial mode of existence forces on animals predilections 

 which in a state of nature are not observed. In nature they are essentially 

 moderate in their desires, but* when domesticated will eat what they 

 would in a state of nature avoid, and never appear to be satisfied, 

 devouring much more than when in the field, filling themselves to 

 repletion. In their natural state the exercise connected with the selection 

 of food is of great importance to the health of the herbivora. They 

 cannot fast long, like the carnivora, nor can they in a single meal con- 

 sume enough to enable them to pass hours or days in a state of torpor 



