70 STRUCTURE AND ECONOMY OF THE HORSE. 



gall bladder. The bile is a yellow bitter fluid, and its chief uses 

 appear to be those of a chemical agent, promoting the decom- 

 position of the chyme, and, also, stimulating the secretion of 

 mucus, and the peristaltic motion of the intestines. 



The Pancreas, or Sweetbread, is also a gland which secretes a 

 thin watery fluid, similar to saliva. It lies close to the spine, is 

 connected with the diaphragm and the left kidney. It is of a 

 pale red colour, and, like other glands, is furnished with arteries, 

 veins, nerves, and absorbents. Its fluid is separated from arterial 

 blood, and is conveyed into the intestines by means of a tube, 

 which empties itself close to that of the liver. 



The Spleen is a peculiar organ, loosely attached to the convex 

 portion of the stomach. It is about three pounds in weight, 

 long, and larger at one end than the other. Its colour is exter- 

 nally blue ; but, when cut into, is the same as venous blood, of 

 Avhich it seems filled. In its structure, it appears to consist of 

 numerous cells. Its use has long been a subject of difficulty and 

 dispute with physiologists ; but it is now supposed to act as a 

 reservoir for superfluous fluid. It has been removed from living 

 animals without subjecting them afterwards to apparent in- 

 convenience ; consequently, its purpose cannot be of vital im- 

 portance. — Ed.] 



CHAP. XVI. 



ON DIGESTION. 



[The horse is strictly a vegetable feeder: in a state of nature 

 his food is confined to the sjrass of the field ; and althoujrli in a 

 domesticated state he largely subsists on nourishment in a more 

 concentrated form, such as grain, yet it is impossible to make 

 him live on animal food ; his teeth, his stomach, and intestines 

 are all adapted for the comminution and digestion of vegetables : 

 the former are broad, for the purpose of grinding the food as in 

 a mill ; and the intestines are bulky, so as to contain a large 

 quantity of food. 



The horse at grass is almost constantly feeding ; he does not, 

 like the ox, gather together large tufts of grass, but he takes a 

 short bite, and delights in a sweet herbage. The manner in 

 which he gathers his food is worthy of notice : he does not bite 

 it off" with his teeth, but having closely embraced a short bite 

 between the incisor teeth or nippers, he pulls it off" by making a 

 slight motion of the head : this is the only duty of these teeth, 

 for the tongue immediately passes on the food to the molar teeth, 

 between which it is ground as in a mill. The under molar teeth 



