ORGANS OF DIGESTION. 317 



crude or less prepared state ; the nutritious portions bear a 

 much smaller proportion to the whole mass, and, accordingly, 

 the food taken is of very considerable bulk. To meet these 

 peculiarities the digestive organs are .much more spacious 

 and more complicated 'than those of the carnivora; means 

 are afforded for detaining the food until the nutriment can be 

 properly extracted, a larger amount of chemical and vital 

 fbrce is employed, and a more abundant supply of "nervous 

 energy afforded. The horse, in a state of nature, is almost 

 continually feeding ; he bites short and well triturates his 

 food, but is almost constantly so engaged ; and though, in a 

 domesticated state, the food is not so abundant' nor so fre- 

 quently taken, it is in a much more' nutritious form. Corre- 

 sponding to these natural habits, we find that though the ali- 

 mentary canal altoge^er is of enormous bulk, the stomach 

 itself is single and of moderate size. Digestion is almost 

 constantly going on ; food is passing out of one orifice of 

 the stomach as it comes in at the other, and the supply of 

 bile is constant, there being no reservoir for it — no gall- 

 bladder. The smallness of the stomach is compensated for 

 by the prodigious bulk of the large intestines. Thus the 

 horse, though an animal that requires a large quantity of food, 

 is yet able to perform great physical exertions, and can make 

 them after a full meal more readily than any other animal. 



The ox, the sheep, and other ruminating animals, have, 

 like the horse, very extensive digestive organs, but very dif- 

 ferently arranged. The horse,i in a state of nature, will 

 rarely get fat ; the ox and the sheep, in good pasture, will 

 almost invariably do so, and will otherwise greatly increase 

 in size ; the digestive organs are, therefore, more bulky than 

 in the horse, and much more complicated. The intestines 

 are of greater length, though not so large, and instead of 

 one stomach there are no less than four. 



The natural food of the sheep is embraced by the joint 

 apposition of the incisor teeth of the under jaw and the 

 cartilaginous pad on the upper, and is separated mainly by 

 the action of the muscles of the head' and neck, giving the 

 head an almost constant motion, which may be readily ob- 

 served when the animal is feeding on pasture. The grass 

 is torn off, not bitten; but when turnips form the food the 

 teeth are more actively employed, and consequently are 

 more worn and become sooner lost. The food being mode- 

 rately chewed by the molar teeth or grinders, to which it is 

 27* 



