74 



J. N. LaDgley, 



in life, the granules are often fairly distinct on teasing out the cells 

 in salt solution; in the pyloric gland -cells the granules are usually 

 so indistinct that I should not feel justified on the microscopic ap- 

 pearances alone, in assuming that they are not due to a slight alte- 

 ration in the hyaline interfibrillar substance. There are however other 

 grounds which render, I think, this assumption justifiable. 



In all cells which contain much pepsinogen, distinct granules are 

 present. Further, the quantity of pepsinogen varies directly with the 

 mass (number and size) of the granules; that is, pepsinogen when 

 present in cells in sufficient quantity to be readily observed is pre- 

 sent in the form of granules, hence it seems probable that in cells 

 which contain a small amount only of pepsinogen, the pepsinogen is 

 also present in the form of granules which however are not conspi- 

 cuous on account of their small size. 



And in fact in most cases, the less pepsinogen a cell contains 

 the smaller are its granules ; this is especially well seen in the gastric 

 glands of lower vertebrates, in some of these moreover the glands 

 near the pyloric region may be semi-transparent and apparently ho 

 mogeneous during life whilst after treatment with osmic acid, granules 

 become obvious, which except as regards size are like the granules, 

 which are of the anterior region of the stomach visible in life in the 

 cells. Since the granules are in these cases preserved by osmic acid, 

 their detection is easy. 



It is then probable that pepsinogen when present in a cell is 

 present in the form of granules, and that when pepsinogen is present 

 in small quantity the granules will be too small to be easily seen. 

 Now the semi-transparent chief- cells of the posterior gastric glands 

 of the rabbit do contain pepsinogen, but they contain comparatively 

 little; and the still more transparent pyloric gland-cells also contain 

 pepsinogen but they contain much less than the chief-cells; hence I 

 conclude that the granules which are fairly well seen in the one, and 

 indistinctly in the other, in fresh teased out specimens, are really 

 pepsinogen granules comparable to those easily seen in the majority 

 of the chief-cells of mammalian gastric glands. 



With regard to the border cells, there is no satisfactory proof 

 that they contain pepsinogen, and the evidence for. the presence of 



