88 SPECIAL HISTOLOGY. 



show that here, as in animals, it is only particular glands — those 

 in fact of the middle of the stomach — which yield the proper, 

 active secretion ; however, further observations must be made 

 on stomachs in the freshest and most normal state, to confirm 

 this result. In any case, the secretion of the glands is for 

 the most part a fluid, though in the mucus, a small quantity 

 of which usually covers the mucous membrane, we not only 

 meet with half-destroyed cylinder epithelium, but almost 

 invariably, with a certain quantity of proper glandular cells ; 

 and it is impossible to say whether these are essential, or only 

 accidental constituents of the glandular secretion. 



In many animals there are two secretions with different pro- 

 perties corresponding with the two forms of gastric glands, 

 a fact to which Bischoff and Wasmann first drew attention, 

 and which I can confirm. In the Dog, glands with cylinder 

 epithelium exist in the pylorus ; those with round cells in the 

 remainder of the stomach ; there is the same arrangement in 

 Ruminants and in the Rabbit ; whilst in the Pig, it is only 

 the middle of the stomach and especially the great curvature, 

 which presents the latter glands. A series of experiments on 

 artificial digestion, which were carried out by Dr. Goll, of 

 Zurich, and myself, principally with the pig's stomach, afforded 

 the distinct result, that, so far as their solvent powers are 

 concerned, the glands present very different relations ; those 

 with round cells act upon protein compounds which have been 

 coagulated by acids in a very short time i while those with 

 cylinder epithelium, either have no action at all or take a long 

 time to produce a slight effect. Furthermore a well-marked 

 acid reaction is presented by that region of the stomach only 

 in which the former glands are situated. The active organic 

 substance, pepsin, is not contained in the gastric mucus, which, 

 consisting of detached epithelium cylinders, often forms a thick 

 covering over the mucous membrane, but in the finely granu- 

 lated, rounded cells of the peptic gastric glands, to which there- 

 fore the term peptic cells (Labzellen, Frerichs) 1 may well be 

 applied. According to my observations, however, these peptic 

 cells do not necessarily become thrown off, nor take any direct 

 share in digestion, but frequently exert their action simply by 

 pouring the juice which they prepare into the glands.] 

 1 [Literally, " rennet-cells." — Eds.] 



