132 The Cardiae Glands of Mammals 
cat, dog, rabbit, hedgehog and opossum. ‘The results in these instances 
correspond so closely with those in the animals selected for description 
that it was not considered desirable to prolong the histological portion 
of the paper by further description... In every case I was able to satisfy 
myself that the cardiac gland cells were mucin-forming elements, stain- 
ing in the modified solutions of Mayer and related in the usual way to 
the surface epithelium. 
In the opossum, the only marsupial at my disposal, there is a narrow 
zone of cardiac glands, around the cardiac orifice of the stomach. These 
are tortuous tubules entirely composed of mucous cells which stain 
readily in muchematein and mucicarmine. 
It should be remarked that as a rule in those animals in which the 
cardiac zone is extremely small the cells are relatively more active in 
secretion than in animals in which the cardiac zone is large. 
SUMMARY OF RESULTS IN THE HISTOLOGY OF THE CARDIAC 
GLANDS. 
As regards the nature of the cardiac glands, my results are directly 
opposed to those of Ellenberger, Edelmann and Schaffer, who concur in 
the conclusions that they are not mucous glands. Ellenberger con- 
trasts them with the pyloric glands which he regards as mucous glands, 
and expresses the opinion that they are serous glands. Edelmann re- 
.gards the cardiac glands as sui generis, but not mucus-forming. Schaffer 
compares them with the pyloric gland cells and the chief cells of the 
fundus glands which he evidently regards as similar. 
Little importance can be attached to any of these views because they 
are obviously not based on a clear conception of the fundamental struc- 
ture of the chief cell and pyloric gland cell. 
My conclusions are as follows: 
1. The cardiac glands are mucous glands, because their cells contain 
a secretion which stains with Mayer’s muchematein and mucicarmine 
and are connected with the mucigenous epithelium of the surface by 
a transition, the middle point of which is formed by actively dividing 
cells containing little mucin, which occur at the deeper constricted ends 
of the foveolar depressions. It is reasonable to suppose that cells which 
have a common origin from an element that is already differentiated 
as a secreting cell, are not strikingly different in nature. 
2. The cardiac gland cells are fundamentally different from the chief 
cells of the body of the fundus glands, inasmuch as the latter give none 
of the staining reactions of mucin, but, on the contrary, contain two 
characteristic substances which are phases in the elaboration of their 
