alimentary tract of the king SALMON 
79 
Epithelium oj the cardiac stomach . — The cardiac epithelial coat presents on the sur- 
face always a layer of slender cylindrical cells of the usual cylindrical or columnar epi- 
thelial type. Perhaps these cells are more slender than is noted in many animal species. 
Where the coat forms sharp folds the cylindrical cells wall in cross section of the folds 
present great fan-shaped masses. 
The cells are almost always slender at the base and somewhat broader at the apex 
of the cell. They vary in size, but average in thickness 3 at the base and 6 /z at the 
free end. The length of the cells of the free surface varies from 33 to 50 [i. The nucleus 
is in the basal third of the cell. It is a slender oval mass showing a rather close chromatin 
network. The normal size of the nucleus is on an average 2 by 6 /z. The outer fourth 
of the superficial epithelial cell is usually paler, contains less stainable protoplasm, and 
is relativel)^ larger. This zone is one that takes a most active part in fat absorption. 
The cylindrical cells are not granular. Gulland’s “ figure 8 represents a view of the cells 
for Salmo solar. The whole gastric epithelium is thrown into deep folds in the empty 
stomach, folds which are more or less obliterated in the actively digesting organ. When 
the walls are not greatly distended then the folds are deeper and more pronounced, and 
the superficial epithelial coat and the deeper seated gastric glands are rather distorted in 
position and appearance. A more normal relation of the parts of the mucosa is presented 
in the distended stomach, and in such a stomach, moreover, the relations are most 
readily determined. The most superficial of the cylindrical cells, the ones that form the 
free surface bordering on the lumen of the stomach, are the longest and most slender. 
From this surface, extending down into and lining the mouths of the crypts, the cylin- 
drical cells become gradually and uninterruptedly smaller. The only change in type, 
however, is one of relative size of the cells. The crypts themselves vary greatly in 
depth, forming longer or shorter tubes into the bottoms and sides of which the gastric 
glands open. (See fig. 3, pi. xxvi.) 
The epithelial cells lining the tubes of the crypts nowhere present abrupt change in 
structure from the most superficial type. Where the tubes are relatively long the lining 
cells, presumably the neck cells of Gulland, become short, cubical, and of uniform size. 
In the bottoms of the crypts the cubical type of cylindrical cell changes quite suddenly 
to the secreting type. There is no intermediate structurally different type of neck cell 
in the king salmon as suggested by Gulland “ for the Atlantic salmon. The term, 
“neck cell,” when it is used, must refer merely to the fore-shortened type of cylin- 
drical cell. 
The point at which the transition takes place from the cylindrical to the glandular 
type is rather difficult to observ^e, since it seldom happens that a vertical section cuts 
through this critical region. Gulland presents a figure of such a transitional region 
for the Atlantic salmon and calls attention to the change in cell t)^pe. In figure 3, 
plate XXVI, I show the relation as it exists in the adult king salmon. The opening 
between the crypt and the gland duct is distinctly constricted and rarely cut exactly 
through its lumen, except in stomachs taken at a stage of digestion in which the whole 
wall is decidedly relaxed. Then the gland mouth may be more distended or relaxed. 
Paton, D. Xoel, op. cit., p. 5, and fig. 9. 
