456 



THE ALIMENTARY CANAL 



[OH. XXVII. 



Peyer's patches are found in greatest abundance in the lower part 

 of the ileum near to the ileo-csecal valve. They consist of. aggregated 

 groups of lymphoid nodules ; they vary from one to three inches in 



FIG. 385. Transverse section through four 

 crypts of Lieberkiihn from the large 

 intestine of the pig. They are lined 

 by columnar epithelial cells, the 

 nuclei being placed in the outer part 

 of the cells. The divisions between 

 the cells are seen as lines radiating 

 from L, the lumen of the crypt ; o, 

 epithelial cells, which have become 

 transformed into goblet cells, x 350. 

 (Klein and Noble Smith.) 



FIG. 3S6.-A gland 

 of Lieberkiihn in 

 longitudinal sec- 

 tion. (Briuton.) 



length, and are about half-an-inch in width, chiefly of an oval form, 

 their long axes being parallel with that of the intestine. They are 

 almost always placed opposite the attachment of the mesentery. 



When the lymphoid nodules occur singly, as they often do both in 

 small and large intestines, they are called solitary glands, or follicles. 



FIG. 387. Agminate follicles, or Peyer's patch, in a state of distension. 



(Boehm.) 



The Large Intestine in an adult is from about 4 to 6 feet long ; 

 it is subdivided for descriptive purposes into three portions, viz. : the 

 ccecum, a short wide pouch, communicating with the lower end of the 

 small intestine through an opening, guarded by the ileo-ccecal valve ; 



