INTESTINAL MUCOUS MEMBRANE. 163 



gastric follicles, one portion of them occupies the 

 vicinity of the cardiac orifice (those secreting pepsin), 

 whilst the other (consisting of mucous glands) is 

 found near the pylorus ; both have been already 

 described (PL XXV. fig. VIII. ; PL XXVI. fig. I). 



The mucous coat of the stomach is rich in blood- 

 vessels which, first supplying its glands, terminate 

 nearer its surface in a very regular capillary network, 

 the largest meshes of which surround their orifices. 

 Its Jyinphatic vessels communicate with the little 

 glands which lie along the greater or lesser curvatures 

 of the organ. The mode of distribution and ultimate 

 termination of the very numerous nervous branches 

 which it receives from the great sympathetic and 

 pneumogastric, are not clearly demonstrated. 



The mucous membrane of the small intestine, which smaii intestine. 

 in all the essential points of its structure resembles 

 that of the stomach, differs, from it, nevertheless, both 

 in the appearance of its surface, and in the character 

 of certain of its glands. Upon its free surface two 

 species of prominences are noticeable valvulce con- 

 niventes and villi. The former are long semilunar 

 folds, formed by the plaiting of the membrane upon 

 itself; their direction is perpendicular to the axis of 

 the canal, and each occupies the half or two-thirds of 

 its circumference ; they slope . off to a point at either 

 extremity, and are_ connected to each other by little 

 oblique folds. They are very large and numerous in 

 the duodenum, where they overlap each other like 

 shingles on the roof of a house, and in such a manner 

 that their free edges look downwards. As we trace 

 them downwards, following the surface of the bowel, 



