128 The Cardiac Glands of Mammals 
gland cells and are related to the surface epithelium through a similar 
perfect transition. The difference is one of degree rather than kind, 
the cardiae gland cell discharging at a later period of development and 
with obvious reluctance, the mucin-forming function which the pyloric 
gland cell assumes early and performs perfectly throughout life. 
I have not made an exhaustive comparison of the reactions with 
synthetic dyes of the cells composing the pyloric and cardiac glands, 
but so far as I have gone, they have been similar. I should not be sur- 
prised, however, if further experiment revealed differences of staining 
capacity, because it is hardly to be expected that imperfectly function- 
ing secreting cells like those of the cardiac glands would always cor- 
respond, in the phase of elaboration to which they carried their stored- 
up product, with such active elements as the cells of the pyloric glands. 
The fundus gland zone of the pig is of great interest owing to the 
fact that the glands of a very considerable portion of it may be reason- 
ably regarded as intermediate between cardiac glands and true fundus 
glands. These fundus glands are unique among mammalian gastric 
glands in the fact, first noted by Greenwood, that the mucous chief 
cells are not confined to the neck of the gland, but extend into the body 
and many of the glands may be formed of mucous cells and parietal 
cells to the exclusion of zymogenic chief cells even in their deepest 
portions. The ferment-forming chief cells are thus relatively reduced 
in number. 
Thus the cardiac glands of the pig correspond with those of man in 
their muciparous function, in their relation to the surface epithelium, 
and in their comparative inactivity in secretion as indicated by the 
structure of the cell. They differ from those of man in the complete 
absence of parietal and ferment-forming cells except in the inter- 
mediary zone. 
Ill. THe Carprac GLANDS oF RODENTIA. 
In the guinea-pig, the cesophageal epithelium terminates at the open- 
ing of the cesophagus into the stomach in a sort of irregular fringe which 
bears a superficial resemblance to the Grenzfalte of the Myomorpha 
but on microscopic examination proves to be composed of the corneous 
layer of the epithelium only. 
The cardiac glands in this animal are confined to a narrow zone 
about one-third of a millimeter in width. The glands of this area are 
devoid of both parietal and zymogenie chief cells. The cells of which 
they are composed resemble very closely in structure those of the human 
cardiac glands although the distal portion which contains secretion 
