PHYSIOLOGY OF PEPSIN-FORMING GLANDS. 
G7! 
in twenty-four hours from the time of feeding the animal, in others they do not become 
so for several days. It will be noticed that the granules begin to increase before the 
food has left the stomach. 
The Changes which occur in the (Esophageal Glands when the Animal 
is fed with Sponge. 
Hitherto I have spoken of the effect of feeding with worm, i.e., with a readily 
digestible substance ; having in mind Heidenhain’s experiments on the isolated 
fundus in Dogs I was anxious to see what would be the effect on the oesophageal 
glands of mechanical stimulation of the gastric mucous membrane. To this end a 
number of Frogs were fed with sponge. 
If the piece of sponge is small so that it can pass the pylorus a slight effect only is 
produced : usually a thinning of granules in outer portion of the cells of the anterior 
oesophageal glands, and a small zone in the posterior oesophageal gland-cells. 
When the piece of sponge is too large to pass the pylorus, it serves as a continual 
stimulus to the oesophageal glands. The extent of the change produced is within 
certain limits the greater the larger the piece of sponge; it varies, too, widely with the 
condition of the Frog. The changes produced are like those produced by feeding 
with worm, but go on very much more slowly. The first distinct thinning of granules 
is usually not seen for three or four hours, and may not be obvious till even later. 
Tire glands near the stomach are first affected. The disappearance of granules then 
goes steadily on. 
It will be remembered that in the worm-fed animal the granules begin to increase 
in six to twelve hours. After feeding with sponge no such increase occurs until at 
any rate some days. 
The extent to which the disappearance of granules proceeds varies in different cases : 
in many cases two days after feeding* with a rather large piece of sponge, occasionally 
in a less time, scarcely any granules are left; and in some glands not a granule is to be 
seen (Plate 77, fig. 6 (a), 6 (6)). 
When the clear zone is largely developed there are usually to be seen in it, often in rows, fine granules 
much smaller than those which form the remains of the granular zone (see Plate 77, fig. 6 (&)). 
At this stage the diminution, both in the size of the cells and in the size of the 
granules, is very striking. Moreover a very characteristic appearance is imparted to 
many of the glands by the large size of the lumen. The diameter of the lumen varies 
considerably in neighbouring glands; in some it is more than half the length of the 
cells ; when granules remain they form a kind of ragged fringe to it (Plate 77, fig. 5). 
* Nussbatjm (op. cit., s. 749) made some observations upon the direct stimulation of the oesophageal 
mucous membrane, the cardia being ligatured before the auimal was fed with sponge. He found under 
such circumstances that the granules entirely disappeared from the cells in three to five hours. Sewall 
and myself (op. cit., p. 285) were unable to observe any such rapid action. 
