62 FEEDING ANIMALS. 



its anterior portion, called small intestine, but is irregu- 

 larly dilated in its posterior part, and here called large 

 intestine. 



The small intestine in the horse (D D, fig. 1) is a cylindrical 

 tube from 1 to 1M inches in diameter, and is about 24 yards 

 long. The internal surface of the small intestine, like the 

 stomach and other viscera, is provided with a muscular 

 coat, and a mucous membrane ; the former produces the 

 peristaltic motion which moves its contents along toward 

 the ccecum, and the latter is covered with glandular folli- 

 cles which pour out a digestive fluid an alkaline mucus. 

 The small intestine in its duodenal portion receives through 

 two orifices the bile and pancreatic juice, and these with 

 the intestinal mucus, are constantly acting upon and com- 

 plete the digestion of the food passing through it. It is 

 also in this intestine that the nutritive principles of the 

 food are absorbed and pass into the general circulation. 

 This leads into the large intestine, which is divided, in its 

 different portions, into the coecum, the large colon, small 

 colon and the rectum. 



The coecum in the horse (F, fig. 1) is about 3 feet in length, 

 and has a capacity of a little over 7 gallons. This part of 

 the large intestine furnishes a reservoir for the large quanti- 

 ties of fluid ingested by herbivorous animals. Here, what 

 is left of the assimilable matters of the food, is dissolved 

 out and enter into the circulation through the absorbents 

 of the mucous membrane of the large intestine. 



The colon (E E) is divided into two parts, the large and 

 small colon. The former is from 10 to 13 feet in length, and 

 there contracts into the small colon. It has a capacity for 

 holding 18 gallons. The small colon is about twice the 

 diameter of the small intestine, and about 1O feet in 

 length. The large colon absorbs fluids and soluble nutri- 

 tive matters. When the matters taken for food reaches the 

 small colon, deprived of its assimilable principles, the ex- 



