PHYSIOLOGY OF PEPSIN-FORMING GLANDS. 
6G9 
coloration.'"' Neither show any granules. The distinction comes out, however, on 
keeping the specimens in glycerine (Plate 77, fig. 2), partly by the protoplasmic portion 
becoming darker, and partly, I think, by the mucigen portion becoming lighter. The 
distinction is also clear if the osmic-hardened stomach is left in alcohol a week or 
more before sections are made. In the sub-cubical cells the nucleus is placed in the 
outer portion of the cell and takes up nearly the whole of its transverse diameter. 
The. glands in the intermediate zone .—In the intermediate zone between the oxyntic 
and pyloric glands, the glands become shorter, the ellipsoidal cells of the oxyntic glands 
become fewer, and some of them are replaced by cells similarly shaped but containing 
few or no oxyntic gland granules; amongst these glands are found simple pyloric 
glands, which increase in number towards the pylorus until they form the sole con¬ 
stituent. Close to the intestine the glands are very irregular in form, and become 
more and more simple depressions of the surface epithelium. 
The Changes which occur in the (Esophageal Glands during Digestion. 
Sewall and myselft have previously given some account of the most striking 
event of secretory activity, viz.: the using up of the cell granules. We found that in 
the normal hungry Frog the cells were granular throughout and that very soon after 
feeding the animal the granules began to disappear, and continued to disappear until 
about the sixth hour ; at some later period which we left undetermined the granules 
began to increase, and increased steadily until the cells were again granular throughout. 
To this account I would make one or two additions. 
When a Frog is fed, the oesophageal glands near the stomach show greater signs of 
secretory activity than glands more remote. This is the case, at any rate, when only 
a moderate amount of food is given. The glands which are nearest the stomach are 
the first to show a clear zone, then those just above, and so on to the beginning of the 
oesophagus. 
Generally speaking, the smaller the amount of food given the more is the obvious 
effect confined to the oesophageal glands that are near the stomach, and within certain 
limits the more digestible the food and the greater its amount the more simultaneous 
is the change taking place in the glands. 
Hence, in comparing the state of the glands at different times after food has been 
given, it is important to take a strip down the whole length of the oesophagus; and 
in comparing the amount of pepsin in different stages of digestion it is important to 
take pieces of the oesophagus from a corresponding region. 
As the outer zone increases the granules in the inner zone become smaller, the 
* The mucous cells are also fairly equally stained in specimens treated with osmic acid only. This 
probably explains how it is that Bleyer (quoted by Partsch) failed to observe mucous cells in osmic acid 
specimens. 
f Op. cit. 
