THE LARGE INTESTINE. 151 



Mucous Membrane, is covered with columnar non-ciliated epithelium, and 

 thrown into crescentic transverse folds, the Valvtdcz Conniventes, or valves 

 of Kirkring. It also presents numerous vascular projections or Villi, each 

 formed of basement membrane, epithelium, a lacteal vessel, a capillary 

 plexus, granular corpuscles, and longitudinal muscular fibres, and number- 

 ing about four millions in the whole length of the intestine. 



Cellular Coat, contains the vessels of the intestine, and connects the other 

 two coats together. 



Muscular Coat, consists of external longitudinal and internal circular 

 fibres, the former being thinly distributed along the bowel, the latter form- 

 ing a thick layer, but not making complete rings. 



Describe the Glands of the Small Intestine. The mucous membrane 

 of the small intestine contains 



Crypts of Lieberkuhn, or Simple Follicles, are minute tubular depressions, 

 found all over the intestine and also in the stomach. 



Brunner's Glands, are small conglomerate glands, found only in the duo- 

 denum and the first part of the jejunum, being most numerous near the 

 pylorus. In structure they resemble the pancreas. 



Solitary Glands, are lymphoid organs, situated throughout the intestine, 

 though most numerous at the lower portion of the ileum. They are agmi- 

 nated into some 20 or 30 oval patches, named 



foyer's Patches, on the surface opposite to the mesenteric attachme its, 

 some of which are as much as 4 inches in length. They are most numer- 

 ous and largest in the ileum, and are most developed during digestion. 



THE LARGE INTESTINE. 



Describe the Large Intestine. It is about five feet long, of large calibre, 

 sacculated, consists of the same coats as the small intestine, the mucous being 

 smooth, and without villi, the muscular having its longitudinal fibres collected 

 into 3 narrow bands, producing a pouching of the tube. It presents the fol- 

 lowing PARTS andflom/s, viz. 



OECUM, or Caput Ccecum Colif a dilated blind pouch behind the entrance 

 of the small intestine.* It is the beginning of the large intestine, lies in 

 the right iliac fossa, and is two-thirds covered by peritoneum. 

 Appendix Vermiformis, & a blind prolongation about 3 to 6 inches long, 

 narrow and worm-like, directed backwards and* upwards from the lower 

 part of the caecum, being retained by a fold of the peritoneum. 

 fleo-ccecal Valve, or Valve of Bauhin, guards the entrance of the small 

 intestine, being formed by two crescentic folds of the mucous and cellular 

 coats and circular muscular fibres, each covered with villl on the. side 

 toward the ileum, but smooth on the caecal side. 



