120 The Cardiac Glands of Mammals 
A point remains to be discussed which is of the greatest importance 
in deciding the origin of the cardiac glands, namely, the occurrence in 
them of the other characteristic elements of the fundus gland, the pa- 
rietal cells and the pepsin-forming chief cells. Schaffer has shown that 
the former occur in the cardiac glands of man in varying numbers. 
This observation I can confirm. The parietal cells of the human car- 
diac glands exhibit the characteristics which have been described for 
those of the fundus glands by Zimmermann, g8, are frequently binu- 
cleated, and contain distinct intracellular ducts. The parietal cells 
are not confined to any special region of the cardiac mucosa nor to any 
definite part of the gland, although I have not observed any in relation 
with the cylindrical epithelium of the foveole. 
Schaffer also saw among the usual transparent cardiac glands certain 
more deeply staining tubules which he describes as follows: 
“Daneben findet man Driisenschlatiche welche nahezu cubische Zel- 
len mit compactem stark gefirbtem Protoplasmakorper und kugeligem 
Kern besitzen; dies sind offenbar im Gegensitze zu der vorigen durch 
das Reagens nicht verinderte oder ruhende Zellen vor oder nach der 
Secretentleerung.” These may have been resting cells, as Schaffer sug- 
gests, or zymogenic chief cells, which I have found to be of quite fre- 
quent occurrence in my preparations. In Miiller’s fluid preparations 
the distinction between these two kinds of cells is not obvious owing to 
the solvent action of the fluid on the granules and prozymogen. 
In my material these zymogenic chief cells occurred even more fre- 
quently than parietal cells. Their presence served to throw into strong 
relief the differences between them and the ordinary cardiac gland cells. 
Like the parietal cells they showed no special preference for any part 
of the cardiac region but occurred in the highest as well as the lowest 
portion of it. In the simple tubular glands of the distal region, they 
were usually found at the deep end of the tubule, but in the complex 
tubulo-racemose glands near the cesophageal epithelium their arrange- 
ment was less definite. Sometimes they occupied in common with a 
few parietal cells the terminal tubules of a gland. Some of the large 
compound glands at the margin of the @sophagus were almost exclusively 
zymogenic, in others some of the tubules were mucous, the rest zymo- 
genic, while in the majority of cases one or two tubules only or a few 
cells in some of the tubules presented the structure of chief cells. The 
tubules formed of zymogenic chief cells are as a rule narrower and 
have a smaller lumen than those formed of mucous cells. 
In sections stained in toluidin blue it is possible to distinguish the 
two kinds of tubules in the cardiae glands with a very low power, owing 
