508 SPECIAL HISTOLOGY. 



free ends; in many genera, they are of two very distinct kinds, the 

 mucou-s gastric glands, with a cylinder epithelium and the peptic gastric 

 glands (Magensaftdriisen) with cells similar to those which exist in man. 

 A more detailed description of some forms will be found in my " Mikro- 

 skop. Anatomic" (II. 2, p. 140) ; and I here subjoin figures (p. 507) of 

 the two forms of the glands in the dog, merely to render my meaning 

 intelligible. 



The secretion of the gastric glands has not been so completely exa- 

 mined in man, that we can say with certainty whether they all secrete 

 gastric juice or not. A few experiments which I instituted with regard 

 to this point, tend to 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 ivitli different properties 

 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, 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 form a thick covering over the mucous membrane, but in the finely 

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

 fore the term peptic cells (Labzellen, Frerichs)* may well be applied. 

 According to my observations, however, these peptic cells do not neces- 

 sarily become thrown off, nor take any direct share in digestion, but 



* [Literally, "rennet-cells." TRS.] 



