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HAND-BOOK OF PHYSIOLOGY. 



similar change during secretion; but 'they are more branched and convo- 

 luted and their ducts are longer. (Watney.) The duct of each gland 

 passes through the muscularis mucosse, and opens on the surface of the 

 mucous membrane. 



(3.) The glands of Peyer occur chiefly but not exclusively in the small 

 intestine. They are found in greatest abundance in the lower part of the 



FIG. 187. 



FIG. 188. 



FIG. 187. Transverse section of injected Peyer's glands (from Kolliker). The drawing was taken 

 from a preparation made by Frey: it represents the fine capillary-looped network spreading from 

 the surrounding blood-vessels into the interior of three of Peyser's capsules from the intestine of the 

 rabbit. 



FIG. 188. Vertical section of duodenum, showing a, yilli; b, crypts of Lieberkuhn, and c, Brun- 

 ner's glands in the submucosa s, with ducts, d: muscularis mucosae, m; and circular muscular coat/. 

 (Schofield.) 



ileum near to the ileo-caecal valve. They are met with in two conditions, 

 viz., either scattered singly, in which case they are termed glandules soli- 

 tarice, or aggregated in groups varying from one to three inches in length 

 and about half-an-inch in width, chiefly of an oval form, their long axis 

 parallel with that of the intestine. In this state, they are named glandules 

 agminate, the groups being commonly called Peyer's patches (Fig. 189), 

 and almost always placed opposite the attachment of the mesentery. In 

 structure, and in function, there is no essential difference between the 

 solitary glands and the individual bodies of which each group or patch is 

 made up. They are really single or aggregated masses of adenoid tissue 



