THE STOMACH. 509 



frequently exert their action simply by pouring the juice which they 

 prepare into the glands. 



151. We have seen, that beside the glands, only a very scanty tis- 

 sue enters into the mucous membrane. Around their extremities alone, 

 do we find a dense, continuous, reddish layer 0-022-0-044 of a line in 

 thickness (Briicke), the muscular layer of the mucous membrane, con- 

 sisting of bundles of common connective tissue and of smooth muscles, 

 interwoven, the latter of which cross one another principally in two 

 directions, and, in the Pig, even pass between the glands and into the 

 plicce villosce. In man, we meet only with vessels, and an amorphous 

 connective tissue, without elastic fibrils, interposed between the glands, 

 forming at the surface of the mucous membrane, a clear, perfectly 

 homogeneous stratum, the structureless membrane of authors, which is 

 continuous with the membrane proprice of the separate glandular 

 tubes, but cannot, like them, be isolated. 



The whole internal surface of the stomach from the cardia (where 

 the tessellated epithelium of the oesophagus terminates by a sharp 

 notched edge), possesses a simple covering of cylindrical cells, about 

 0-01 of a line long on the average, which lie immediately upon the 

 outermost homogeneous portion of the mucous membrane, without any 

 interposed substance. During life, this cylinder epithelium whose 

 other relations will be treated of below, in describing the small intes- 

 tine, where a layer of exactly similar nature is to be met with is 

 closely united with the mucous membrane, though not so intimately, but 

 that its elements are, at times, detached to a larger or smaller amount 

 by the mechanical violence to which it is necessarily occasionally sub- 

 jected in the stomach. After death this takes place so readily, that the 

 cells can be seen in situ, in man, only under very favorable circum- 

 stances. Perhaps, also, detachment of the epithelium to a certain ex- 

 tent may take place normally, in one way or another, during digestion; 

 at least, in animals the quantity of loose epithelial cells is often very 

 great and they frequently almost entirely constitute the mucous coating 

 which covers the surface of the stomach. 



Besides the tubular glands, the stomach also contains, though they 

 are inconstant and vary very much in number, closed follicles the so- 

 called lenticular glands, which are identical in structure with the soli- 

 tary follicles of the small intestine, and therefore need not be further 

 described in this place.* 



* [" Although it may be that the lenticular glands of the stomach are always present in 

 children, they are certainly inconstant in adults, since in many cases no trace whatever can 

 be discovered of them. In other instances they are exceedingly numerous, covering the 

 whole surface of the stomach, but in this case, the invariably diseased state of the alimen- 

 tary tract, suggests the idea, that they stand in some connection with it. In many mammalia 

 no trace of such structure is to be found, while, according to Bischoff (Mull. Arch. 1838), 



