TEE INTESTINES. 



479 



already given when speakinc: of the attachments proper to the cjecum. The 

 muscular tunic is formed of circular fibres, crossed externally by longitudinal 

 bands, which maintain the organ in transverse folds. The itmcous membrane is 

 thicker than that of the small intestine, and is also distinguished from it by the 

 absence of the Bruimrriaii and atjmiiuttpd (jlaiuh. It has, however, the solitary 

 follicles and crypts of Lieberkuhn, as well as some few intestinal villi. The blood- 

 vessels are the ccecal arteries and veins. The lymphatics pass to the sublumbar 

 receptacle ; the nerves are derived from the great mesenteric plexus. 



Functions. — The coccmn serves as a reservoir for the enormous quantities of 

 fluid ingested by herbivorous animals. The greater part of this fluid in its rapid 



Fig. 282. 





OENERAL V'EW OP THE INTESTINES OF THE HORSE (SEEN FROM THE RIGHT SIDE, WITH THE 

 PELVIC FLEXURE AND A PORTION OF THE SMALL INTESTINE CARRIED BEYOND THE 

 ABDOMINAL CAVITY). 



a, tEsophagu'i; 6, right sac of the stomach; c, small intestine, showing its origin or duodenal por- 

 tion, encircling the base of the ca?cum ; d, c.ecum ; e, origin of the large colon; /, first portion 

 of the large colon ; g, supra-sternal flexure ; h, second portion of the large colon ; i, peh'ic liexure; 

 j, third portion of the large colon; k, diaphragmatic flexure; I, fourth portion of the large colon; 

 m, termination of the free colon; n, rectum; o, mesentery proper; p, colic mesentery (meso- 

 colon); q, anus; r, internal inguinal ring; s, spermatic vessels; t, deferent canal; u. bladder; v, 

 vesiculfe seminales; x, pelvic enlargement of the vas deferens; y, prostate; z, suspensory 

 lignnient of the penis. 



passage through the stomach and small intestine, escapes the absorbent action 

 of the villi and accumulates in the caecum, into which it may be said to wash 

 the alimentary mass it comes in contact with : it thus dissolves the soluble 

 and assimilable matters this mass may yet contain, and so favours their entrance 

 into the circulation, through the immense absorbing surface formed by the 

 mucous membrane of the large intestine. 



The aliment undergoes still further change, and digestion is completed in 

 this viscus, principally in the Herbivora. 



B. Colon. 

 The colon is divided into two portions, which differ from each othei in 



