THE DIGESTIVE TEACT. 



597 



proof; here acinous mucous glands begin to appear, blending 

 with those of the duodenum. 



The connective tissue of the mucosa of the stomach, especially 

 in children, is composed largely of the myxomatous variety and 

 abundantly supplied with lymph-corpuscles. Both in the fundus 

 and the pyloric portion of the stomach of man lymph-tissue 

 appears as follicles and groups of follicles, which by mistake 

 have been termed " lenticular glands." Their number, however, 

 varies greatly, and in the localities where they exist pepsine 

 glands are not found. 



The mucosa of the stomach has a nearly continuous layer of 

 smooth muscle-fibers, composed of circular and longitudinal 

 bundles ; the circular fibers send pro- 

 longations between the tubular glands. 



The muscle-layers of the stomach 

 proper are of considerable width, and P 

 principally arranged in two layers 

 an inner circular and an outer Ion- 

 gitudinal ; the bundles of both being 

 freely interlaced with oblique bundles. 

 The circular layer produces the sphinc- 

 ter-muscle of the pylorus. 



(5) The Small Intestine. In trans- 

 verse sections of the small intestine 

 the layers constituting its wall appear 

 as follows : (a) the mucosa, producing 

 reduplications above the level of the 

 inner surface, the mill, and reduplica- ^ cuboi dai epithelia of the tubular 



tions below the level Of the inner SUr- glands; P, epithelia laden with pep- 

 ., . n , .... T -, -, X71 sine ; G, connective tissue between 



face, the tubular intestinal glands ; (b) the tubuies, containing injected 

 the submucous layer, holding circular wood-vessels. Magnified 300 mam- 



HORIZONTAL SECTION. 



I 



and longitudinal layers of smooth 



muscle-fibers, and a varying amount of lymph-tissue (the so- 

 called adenoid tissue) ; (c) the muscle of the intestine proper, 

 composed of a broad circular and a narrow longitudinal layer of 

 smooth muscle-fibers ; and (d) the covering peritoneum. (See 

 Fig. 255.) 



The mill are reduplications of the mucosa, of a conical or cyl- 

 indrical shape, very long and narrow in portions where the mus- 

 cle of the intestine is contracted; broad and short, on the 

 contrary, where the muscle of the intestine is extended. In the 

 highest degrees of distension (by gaseous material) the inner 



