PHYSIOLOGY OF PEPSIN-FORMING GLANDS. 
G85 
During tlie latter part of the digestive period there is in the Toad as in the Frog, a 
more or less complete restoration of the normal quiescent state of the gland-cells. 
The restoration, however, does not take the same course in all animals ; usually as the 
cell increases in size there is a corresponding increase in the number of the granules ; 
this is not always the case, for in some Toads, especially in the gastric oxyntic glands, 
the formation of granules does not keep pace with the growth of protoplasm. 
One other variation on the normal course of events is worth mention : occasionally 
there is no perceptible change in the anterior gastric glands during the first three or 
four hours of digestion ; since it can scarcely be doubted that the glands secrete during 
this time, we are led to infer (cp. below, p. 704) that the apparent absence of change 
is due to the formative keeping pace with the excretory processes. 
Fasting causes changes like those which occur in the first stage of digestion, with 
the exception that the mucous cells of the necks of the glands become more instead of 
less prominent. This is perhaps only the case when the fasting is not too prolonged. 
The posterior oxyntic glands are usually more affected than the anterior. 
Feeding with sponge does not cause very great changes in the oesophageal or gastric 
glands, although a very acid secretion with a high peptic power is obtained : the cell- 
granules become smaller, but I have not observed that they are more affected in one 
part of the cell than in another. 
The Pepsin-Content of the (Esophageal and Gastric Glands. 
As in the Frog so in the Toad, the amount of pepsin contained by a definite weight 
of dried mucous membrane is less as the cells become less and less granular during 
digestion. I have made no experiments to determine the pepsin-content of the 
mucous membrane in successive hours after feeding, but have analysed for pepsin only 
such cases in which I could be certain of a difference in the amount of granules 
contained by the respective gland-cells. 
I have also compared the amounts of pepsin contained by the different parts of the 
oesophagus and stomach. The method of proceeding was like that described above in 
the case of the Frog. The amount of pepsin contained by the parts was found to vary 
directly with the amount of granules contained by them. The latter part of the 
oesophagus and first part of the stomach contains most pepsin; the amount of pepsin 
is rather less in the succeeding part of the stomach ; the posterior gastric region in 
which these glands are not markedly granular in life contains considerably less pepsin 
than the preceding ; the pyloric region contains only a very trifling quantity. 
