Ry oR, Bensley - = 129 
stains much more intensely in muchematein and mucicarmine. As in 
the human subject, the mucigenous distal zones of the cells vary in 
extent, from a narrow border along the lumen to one-half or two-thirds 
_of the cell. Rarely the whole cell is filled with secretion but not to 
such an extent that the shape of the nucleus is materially altered by 
compression. 
The transition from this area to the fundus gland area, appears under 
a low magnification to be an abrupt one, but closer inspection shows that 
this is due to the sudden appearance of the parietal cells in great num- 
bers. The glands which immediately succeed the cardiac glands are 
composed entirely of mucous cells and parietal cells. The ferment- 
forming chief cells make their first appearance at the very bottom of 
the glands, increasing rapidly in number and displacing the mucous 
cells until the latter are confined to the neck of the gland. Thus, there 
is, if one leaves the parietal cells out of consideration, a gradual transi- 
tion between the cardiac glands and fundus glands. There is also a 
gradual transition in the nature of the cells composing the gland to 
the cells of the free surface similar to that shown to exist in the pig 
and in man. 
In Arctomys monax the cardiac glands occupy a zone about 2 mm. 
in width around the opening of the cesophagus. They are for the most 
part simple tubular structures slightly expanded at the lower extremi- 
ties, and opening at the upper end into wide and deep depressions. 
Neither parietal nor zymogenic chief cells are present in these glands 
and the cells differ from those of the animals already considered in the 
fact that the secretion completely fills the cell, the nucleus on this 
account exhibiting a basal position and a crescentic form. The transi- 
tion to the fundus zone is as in the guinea-pig except that the parietal 
as well as the chief cells gradually increase in number as the fundus 
gland region is approached. The secretion of the cells stains readily in 
muchematein, mucicarmine and particularly in methyl blue, enabling 
one to distinguish readily the cells from the ferment-forming cells 
which in Arctomys as in the Rodentia generally, exhibit a very well- 
developed proximal zone filled with prozymogen. 
In the Myomorpha, with the exception of Myoxus, the stomach is 
divided into a right and left portion. The glands are entirely confined 
to the right division of the stomach, the left being lined by a non-glan- 
dular stratified squamous epithelium similar to that of the cesophagus. 
The line of junction of the two divisions is marked internally by a 
well-defined fringe, the Grenzfalte, which is really a fold of the mucous 
membrane. Corresponding to this externally there is a more or less 
9 
