272 HISTOLOGICAL CHANGES. [BOOK n. 



renewed vigour, so in the pancreas with the disappearance of the 

 granules from the inner zone, there is a rejuvenescence of the pro- 

 toplasm, to be followed both in the one case and the other by a 

 subsequent conversion of the protoplasm into a product, viz. 

 mucigen and trypsinogen respectively. In both cases the product 

 of the protoplasmic metabolism is deposited in the inner parts of 

 the cell, though the line of demarcation between the inner and 

 outer zone is much more distinct in the pancreas than in the 

 mucous gland. In the former abundance of granules is identical 

 with a broad inner zone, scarcity of granules with a broad outer 

 zone; and similarly the growth of the new protoplasm is most 

 obvious as an increase of the outer zone. In the mucous cell too 

 the mucigen appears on the inner side of the cell. This distinction, 

 however, between an inner and outer zone is not an essential 

 feature of the matter, though probably the growth of new proto- 

 plasm naturally tends to take place at a greater rate on the side 

 of the cell most exposed to the blood-stream, i.e. on the outer side 

 towards the basement membrane, and the deposition of zymogen or 

 mucigen tends to be greatest on the other side nearer to the lumen, 

 into which its products are about to be discharged. 



When we come to study other glands, such as the serous 

 salivary glands, the glands of the stomach, and the hepatic cells, 

 we have evidence that in these also the same essential processes 

 are going on. Certain special features however are in various 

 instances met with, and, these becoming exaggerated by particular 

 modes of preparation, are apt to obscure the normal series of 

 events. 



Thus in the case of the glands of the stomach, if we were 

 to trust exclusively to the indications given by sections of glands 

 hardened in alcohol, we should be led to make the following state- 

 ment. In an animal previous to taking a meal, the central or ' chief 

 (as distinguished from the ovoid, 'border,' or 'peptic') cells of the 

 gastric glands are pale, finely granular, and do not stain readily 

 with carmine and other dyes. During the early stages of gastric 

 digestion, the same cells are found somewhat swollen, but turbid 

 and more coarsely granular ; they stain much more readily. At a 

 later stage they become smaller and shrunken, but are even more 

 turbid and granular than before, and stain still more deeply. 

 This is true, not only of the central cells in the so-called peptic 

 glands, but also of the cells of which the glands of the pyloric end 

 of the stomach are built up. The ovoid or border cells appear 

 swollen during digestion, and project more on the outside of the 

 gland, but otherwise seem unchanged. This series of events is 

 different from that which we have seen to take place in the pancreas, 

 inasmuch as the cells appear to become more granular instead of less 

 granular during activity. But we have reason to think that the 

 granular character of the gastric cells thus seen during digestion 

 is due to some special material precipitated by the alcohol, where- 



