12 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



Relying on their observation that in the rabbit there is a gradual diminution in the 

 number of granules in the chief cells, from the fundus along the greater curvature, 

 and on the undoubted fact that the pyloric secretion contains a proteolytic ferment, 

 these observers concluded "that the pyloric gland cells and the chief cells of the 

 fundus are fundamentally the same," and that " the chief cells of the fundus " are " a 

 highly differentiated form of the pyloric gland cells." Stohr? in 1882 arrived at a 

 similar conclusion, as a result of his researches on the stomach of man, the cat, dog, 

 and badger. 



Many investigators, however, as a result of physiological experiment and 

 observation, have come to the conclusion that the pyloric gland cells are something 

 quite different from the chief cells of the fundus gland. Among these may be 

 mentioned Nussbaum,^ Sappejr,? Bonnet, « and Bikfalve, who regard the pyloric 

 glands as mucous glands. The most recent contribution to this subject is that 

 contained in the Lehrbuch der Vergleichenden Mikroskopischen Anatomic, pub- 

 lished this year by Oppel, of Freiburg. From an exhaustive examination of the 

 literature of this branch of research, and from personal observation, this author* 

 concludes that " Die Pylorusdrusenzellen sind Zellen sui generis welche sich sowohl 

 vom Oberflachenepithel wie von den Hauptzellen unterscheiden. Sie sezernieren 

 pepsinhaltigen Magensaft." 



One has only to consider the conflicting nature of the results achieved, or to 

 observe the various ways in which similar observations have been interpreted, to 

 convince oneself that the solution of the problem of the morphology and physiologyi 

 of the mammalian pyloric gland is not to be attained by the ordinary methods of 

 physiological research. 



It appeared to me that some information might be afforded by a careful study, 

 of the structure of the cells of the various gastric glands, at different periods of 

 digestion, together with a comparison of the structure of the cells in the various 

 vertebrate classes. In order that this investigation might not be open to th^ 

 objection I have urged in reference to the work of Heidenhain and Ebstein, it was 

 necessary to find some agent that would fix equally well the form and contents of 

 the cell. To the difficulty of accomplishing this, I have already alluded, in speaking- 

 of the work of Langley, who found that by the use of osmic acid he could preserve 

 the granules in the chief cells of a few mammals only. It has since been found that 

 mercuric chloride, in saturated aqueous solution, would fix perfectlj'- the zymogen^ 

 granules of many glands. This reagent, as well as the various osmic acid mixtures, 

 were tried and found to possess certain disadvantages. Whilst they fixed perfectly 

 and satisfactorily the cells of the surface, and of the deepest portions of pieces of 

 mucous membrane immersed in them, the zymogen granules had quite disappeared 

 from the middle regions of the glands. Alcoholic solutions of mercuric chloride 

 "were then tried, with the result that whilst the zymogen granules of the whole gland 

 were well preserved, the cells themselves had undergone considerable change of 

 form. It was subsequently found that the addition of an equal volume of two per 

 cent, aqueous solution of potassium bichromate to the alcoholic solution of 

 mercuric chloride, would prevent the shrinkage of the cells, and at the same time 

 effect a satisfactory fixation of the zymogen granules in all parts of the glands 

 containing them. 



With the help of this reagent I have investigated the stomachs of several 

 mammals, and of members of the lower vertebrate classes, and have been led to 

 conclude, that the relationship of the pyloric glands to the glands of the fundus 

 region is, within certain limits, a constant one, and that the pyloric glands are to be 

 regarded as feebly differentiated structures, corresponding in the nature of their 

 cells to the upper portions of the fundus glands. 



(7) Archiv f. Mik. Anat. Bd. XX. 



(8) Archiv f. Mik. Anat. Bd. XXI. 



(9) See Oppel. Lehrbuch der Vergleichen Mikroskopischen Anatomie, p. 269. 



