124 
fi 
The Cardiac Glands of Mammals 
Tur CARDIAC GLANDS OF THE PIG. 
It is in this animal among placental mammals that the cardiac glands 
reach their greatest extent. 
= Foveola 
gastrica 
ee Neck of gland and 
point of transition 
of epithelium 
sf -tnp of smooth 
oh, muscle fipres 
‘fees--Muscularis 
mucosae 
FIG. 6. 
mucosa of the cardiac gland zone of 
Vertical section of tunica 
x 72. 
pig. 
They occupy fully one-third of the avail- 
able surface of the mucous membrane, 
comprised in a triangular area at the 
left extremity of the stomach. ‘The mu- 
cous membrane of this area is only a 
fraction of the thickness of that of the 
middle or fundus gland region and con- 
tains throughout glands composed of 
but one kind of cell. 
As regards the general arrangement 
and shape of the glands and the nature 
of the interglandular tissue, little can 
be added to the admirable descriptions 
of Ellenberger, 88, and Greenwood, 85. 
Fig. 6 shows a section of the mucous 
membrane of this region as seen under 
a low power objective. The superficial 
portion of the mucous membrane is oc- 
cupied by the closely-set foveole of the 
glands, which are much narrower and 
more numerous than in the fundus re- 
gion. The foveole descend in the mu- 
cous membrane, becoming narrower as 
they go and at their lower ends receive 
one or two glands. These are wavy 
tubules branching but slightly, usually 
very narrow at their upper ends but 
frequently presenting at their lower 
ends a bulb-hke expansion containing a 
larger lumen. 
The surface epithelium of this stom- 
ach, while similar in all important details to that of other mammals is 
unique in one respect; the theca of mucus is of extraordinary size and 
as a result nearly fills the cell, the nucleus being flattened by compres- 
sion in the base of the cell. 
Similar cells line the upper portions of the 
foveole, but it is seen that on going down the sides of the latter the 
mass of mucus becomes relatively smaller and the nucleus rapidly ex- 
pands to its normal spherical shape. 
