228 Gastric Glands of Dog after Gastroenterostomy 
ing peripheralward, and a reversal of this process during the following 
five or six months, during which there is a replacement of these mucous 
cells by ferment cells, extending centralward. The same phenomena 
followed the suturing of simple incisions which I made through the 
gastric mucosa in the fundus region. Throughout all stages of these 
processes the increase in number of one kind of cell is exactly pro- 
portional to the decrease in number of the other kind, a fact which 
suggests strongly that the new mucous cells formed in the first month 
and the new ferment cells formed in the following months arise each by 
transformation of previously existing cells of the other variety. This is 
confirmed by the fact already noted that when the process of ferment 
formation in cells is extending toward the anastomosis during the four 
or five months following the one immediately after the operation, the 
most advanced ferment cells, that is those nearest the line of union, 
contain only a very few zymogen granules. During the first month, 
‘too, while the mucus forming process is extending into gland bodies 
farther and farther from the anastomosis, the most advanced mucous 
cells contain only a little mucus, which stains feebly, while those near 
the line of union are almost full of mucus and take a very strong stain 
with mucicarmine. 
A consideration of the other possible modes of derivation of these cells, 
namely, division of previously existing cells of the same kind, or trans- 
formation of parietal cells, shows that they do not arise in either of 
these ways. There are no indications that the new mucous cells which 
are formed within a month after the operation arise by division of pre- 
viously existing mucous cells in the gland bodies. Mitotic divisions 
among these cells are extremely rare and there is no appreciable increase 
in the number of these mitoses after the operation. It is also very 
unlikely that many of them arise by proliferation of the mucous chief 
cells of the gland necks and travel down the glands to replace the 
ferment cells of the bodies, because there is very little, if any, increase 
‘in the number of mitoses in the neck region and there is no evidence 
of active migration of cells at this time. Further, there are no evidences 
of degeneration or disappearance of body chief cells except in the two 
or three glands which degenerate on account of injury by the knife or 
sutures. The new ferment cells which appear in gland bodies between 
the first and seventh months after operation cannot arise by transforma- 
tion of previously existing ferment cells, because examination of pre- 
ceding stages shows that absolutely no ferment cells existed in any part 
of the glands in the situation where new ferment cells arise. The trans- 
formation of parietal cells into chief cells, while suggested by Trinkler, 
