PHYSIOLOGY OF PEPSIN-FORMING GLANDS. 
677 
worm, very marked signs of secretory activity result. The chief feature is the diminu¬ 
tion in the size of the gland-cells ; the nuclei are usually oval, frequently lie close to 
the basement membrane, and are surrounded by only a small amount of darkly staining 
cell substance (see Plate 78, fig. 1). It is to be noted that this gland is much more 
highly magnified than the rest). The recovery, too, is long delayed, and an inner non- 
granular zone is visible in the posterior oxyntic glands for some time after the cells have 
begun to increase in size. The amount of change produced here—and in the case of 
feeding fasting summer Frogs —seems to be greater than that produced by a like 
treatment of normal hungry Frogs. I say the change seems to be greater, since it is 
hazardous to institute a comparison between the amount of change produced in glands 
which start secreting in different states. Assuming, however, that the comparison is 
just, a not unlikely conclusion is suggested, viz. : that the formative processes require 
certain elaborated material, and that during the stimulation of the glands of the 
fasting Frog with sponge, the elaborated material is largely used up, so that the 
rapid waste brought by the presence of digestible food cannot be made good so 
quickly as normally. 
It is worth remark that the oxyntic and oesophageal glands do not necessarily show 
a parallelism in the amount of change they respectively undergo in digestion. Under 
special circumstances the one or the other may be most affected. 
Lastly, we have to consider whether on feeding a Frog there is a preliminary increase 
in the size of the oxyntic cells or in the number or size of the granules contained by 
them, before the decrease sets in. From what I have already said, it will be seen that, 
as far as my observations go, the preliminary increase, if it takes place, can only last a 
short time. Even of such brief increase I have seen no instance. I am not, however, 
inclined to deny that it might under certain circumstances take place. 
Changes occurring in the Pyloric Glands and in the Necks of the Oxyntic: 
Glands during Digestion. 
The changes are of a like nature in both, but usually more strongly marked in the 
former, and, as might be expected, the changes do not run a parallel course in the 
two portions of the stomach. My observations have been made upon osmic acid 
specimens. Of the early stages of digestion I cannot speak with any confidence. The 
mucigen border in all cells frequently appears to be larger and to bulge more at its 
free surface; this I am inclined to attribute rather to a swelling of some constituent 
of the outer part of the cells than to an increase by metabolism. However this may 
be, there is, at the height of digestion with a heavy meal, a very considerable 
diminution in the amount of mucigen in all the cells.' 1 ' The cylinder cells of the 
surface are affected in a similar manner although to a less degree. All the cells, too, 
are smaller. The inner portion of the sub-cubical cells in osmic acid specimens instead 
* Sewail and myself found similar changes take place in the mucous cells of the oesophagus and of the 
oesophageal glands during digestion. (Journal of Physiol., vol. ii, p. 284, 1879.) 
