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HANDBOOK OF PHYSIOLOGY. 



is from about 4 to 6 feet long, is subdivided for descriptive purposes into 

 three portions (Fig. 164) viz. : thecacum, a short wide pouch, commu- 

 nicating with the lower end of the small intestine through an opening, 



FIG. 197. Agminate follicles, or Peyer's patch, in the state of distention. x 5. (Boehm.) 



guarded by the ileo-ccBcal valve ; the colon, continuous with the caecum, 

 which forms the principal part of the large intestine, and is divided into 

 ascending, transverse, and descending portions ; and the rectum, which, 

 after dilating at its lower part, again contracts, and immediately after- 



m, tn 



FIG. 198. 



FIG. 198. Section of small intestine, showing villi, Lieberkuhn's glands and a Peyer's solitary 

 gland, m, m, muscularis mucosae CKlein and Noble Smith.) 



FIG. 199. Vertical section of a villus of the small intestine of a cat. a, striated basilar border 

 of the epithelium; 6, columnar epithelium; c, goblet cells; d, central lymph -vessel; e, smooth 

 muscular fibres; /, adenoid stroma of the villus in which lymph corpuscles lie. (Klein.) 



wards opens externally through the anus. Attached to the caecum is the 

 small appendix vermiformis. 



Structure. Like the small intestine, the large intestine is constructed 

 of four principal coats, viz., the serous, muscular, submucous, and mu- 

 cous. The serous coat need not be here particularly described. Con- 

 nected with it are the small processes of peritoneum containing fat, 



