STEUCTITRE OF THE HORSE. 123 



INTESTINES. 



The intestines are divided into the hirge and small; the two, 

 however, form a continnoii?; miiscnlo-membranous tube, with 

 many widenings and convolutions; their length in an average- 

 sized horse being about ninety feet. The coats of the intestines 

 are similar to those of the stomach. The muscular coat con- 

 sists of two layers of fibers, an outer longitudinal and an inner 

 circular one. In certain intestinal diseases of the horse the cir- 

 cular fibers contract spasmodically, producing strictures. The 

 small intestines are continuous with the stomach at its pyloric 

 orifice. They are about seventy-two feet in length. When fully 

 expanded they hold about eleven gallons. The divisions of the 

 small intestines by anatomists have received the names of the 

 Duodenum, Jejunum, and the Ileum. The jejunum succeeds 

 the duodenum, and includes about two-fifths of the remainder of 

 the small intestines, the ileum constituting the rest; they are 

 attached to the free edge of the mesentery. 



The mucous membranes of the small intestines are furnished 

 with glands and absorbents. Besides the mucous follicles, there 

 are small glands resembling the acini of the salivary glands. 

 They are found in the duodenum, and are known as the glands 

 of Brunner. Very small glands are found throughout the in- 

 testines, known as crypts of Lieberkuhn. The Beyer's patches 

 are found in the jejunum and ileum. They are oval or circular 

 groups of solitary glands. Other isolitary glands, scattered 

 throughout the intestines, resemble very much the sacs forming 

 Peyer's patches. The absorbents originate in the villi, wdiich 

 are small finger-like vascular processes, thickly distributed over 

 the mucous surface, consisting of loops of the lacteal vessels, 

 surrounded by a network of capillaries, fine muscular fibers, and 

 small, granular corpuscles. 



The large intestines consist of the csecum, the great colon, the 

 floating colon, and the rectum. The capcum is much larger than 

 the small intestines. It measures about thirty-six inches in 



