The villi number many millions, and are interesting as containing the 

 lacteals, a set of vessels by which the food is absorbed and conveyed into 

 the system. It is sufficient in this place to say that they present a central 

 tube, which commences with a free extremity above, and ends in a net- 

 work at the base of the villus in the wall of the intestine. These lacteal 

 vessels are each invested by a 

 mantle of smooth muscular tissue, 

 and this again by a plexus of 

 capillary blood - vessels. The 

 whole is enclosed by a trans- 

 parent membrane covered with 

 cells that project into the cavity 

 of the intestine. The Lieber- 

 kuhnian follicles are simple tubes 

 very closely set and lined by 

 columnar epithelium. The se- 

 cretion they pour into the intes- 

 tine has high digestive powers 

 for all kinds of aliment. 



The large intestine con- 

 sists of three parts, the caecum, 

 the colon, and the rectum. The 

 small intestine opens into the 

 first part of the large intestine 

 by an orifice that is guarded 

 by a fold of mucous membrane 

 named the ileo-csecal valve, which 

 prevents the return into the 

 small intestine of the food which 

 has entered the caecum. True 

 villi stop abruptly at this spot, 

 and are not found in the large 

 bowel. 



The csecum is a greatly en- 

 larged portion of the intestine. It occupies the right side of the abdomen, 

 and has a capacity of 7 or 8 gallons. The surface is marked by four 

 longitudinal bands of muscle, which being shorter than the other coats, 

 pucker them into great bulging pouches. The upper extremity is curved 

 and presents two openings, one by which the small intestine terminates 

 in it; and the other very narrow, which communicates with the colon, or 

 second division of the large intestine. 



A, Ileum, orterminnl portion <<f small intestine. B, Caecum. 

 C, E, Large colon. D, Pelvic flexure. V, Single colon. 0, 

 Rectum. H, Anus. The arrows indicate the course taken 

 by the food in the process of digestion. 



