PHYSIOLOGY OF PEPSIN-FORMING GLANDS. 
G81 
further, that in some of the former, granules like those of the oesophageal glands not 
infrequently occur. If, then, the granules are connected with the formation of 
ferment, we should expect a definite weight of the anterior gastric region to contain 
more ferment than an equal weight of the median gastric region. This, in fact, is 
the case (see experiment given below); part of the difference in amount is, however, 
probably due to the difference in the size of the glands in the two regions. 
Lastly, we can consider the pyloric glands. The acid extract of the dried mucous 
membrane does contain some pepsin, for it dissolves carmine-fibrin more quickly than 
hydrochloric acid alone; but the amount is very small, and we know that a small 
amount of pepsin is found in nearly every tissue. I have not compared the ferment- 
content of the pyloric region of the stomach with that of other tissues, since it seemed 
to me that even if any pepsin is produced by the pyloric glands the amount must be 
so small as to be unimportant in digestion. There seemed to me to be no reason for 
ascribing any special function of producing pepsin to the pyloric glands in the Frog, 
and consequently no reason for ascribing any such function to the cells of the necks of 
the oxyntic glands. 
The following experiment will show the method I have used in determining the pepsin-content of the 
oesophagus and different portions of the stomach :— 
Experiment .—Frog killed by destroying brain and spinal cord. GEsophagus and stomach removed, cut 
open longitudinally, and pinned down with the mucous membrane uppermost. A moist sponge is passed 
once over it, starting from the pyloric end, and thus the greater part of the mucus or other stomach 
contents removed. To remove the remaining fluid or mucus the surface of the mucous membrane is 
carefully pressed with blotting paper, then moistened with salt solution, and again pressed with blotting 
paper. 
The oesophagus and stomach are then spread out on a glass slide with the mucous membrane down¬ 
wards and the muscular coat removed. The character of the glands is examined under the microscope 
and the intermediate regions between the different kinds of glands are cut away— i.e., the junction of the 
oesophageal and gastric glands is removed, and that region which contains both oxyntic glands and pyloric 
glands. The oxyntic gland region is then cut through transversely into two, as nearly as possible, equal 
portions. Thus we obtain the mucous membrane of 
(1) CEsophagus. 
(2) First portion of stomach. 
(3) Second portion of stomach, containing no pyloric glands. 
(4) Third portion of stomach, the pyloric region containing no oxyntic glands. 
The glass slide with these four pieces of mucous membrane is put in a warm chamber at about 33° C. 
for one day, and then kept till required in a bell jar over strong sulphuric acid. 
The oesophagus and stomach of several Frogs are treated in the same way. Of (1), (2), and (3), 
003 grm. is weighed out; of (4) 0'015 grm.* 
To each of (1), (2), and (3) 3 cub. centims. of hydrochloric acid (0’2 per cent.) is added, to (4) l - 5 
cub. centim. They are then put in small stoppered bottles, and left for twenty-four hours at 33° C. 
To (1), (2), and (3) 9 cub. centims. hydrochloric acid (02 per cent.) is added, to (4) 4'5 cub. centims. 
Each is well shaken up and filtered. 
* Of the Frogs I have used, two give about 0'03 grm. of (1), three give about the same weight of (2) 
and (3), nine to twelve give about the same weight of (4). 
4 T 
MDCCCLXXXI. 
