398 PROCEEDINGS OF THE CANADIAN INSTITUTE 
of the cell on its free surface is due to the reagents employed. Ebstein® 
found both closed and open cells, the latter form arising from the first 
through the transformation of their contents into mucous. Bieder- 
mann? found the cells always open and the mouth of each containing 
a plug which is chemically and morphologically different from the 
remainder of the cell. The stopper shows a longitudinal striation. 
Regéczy* regarded these cells as ciliated, having found cilia on them 
in the frog and in some fishes, frequently on a portion of the peri- 
pheral membrane. In some cases the cilia were cemented in one 
mass at the end of the cell, and in others, again, he observed the 
absence of these cilia apparently through their withdrawal into the 
cell. They are very easily destroyed by chemical reagents, which 
cause also a swelling up of the contents of the cell. 
The many different views of the structure of these cells are no 
doubt due to observing epithelium prepared in a manner which 
changes more or less its normal appearance. Alcohol, Muller's fluid, 
solutions of potassic bichromate, and ammonia bichromate, cause a 
swelling up and an emptying of the contents of the cell in its outer 
third. When examined in the fresh state all cells have the arched, 
glancing border, apparently due to the meeting of two fluids of dif- 
ferent consistency. The contents are similar throughout the cell, 
and finely granuled, Owing to the action of the reagents mentioned: 
the outer two-thirds of the cell becomes clear and glassy, and the 
arched border is absent. When a specimen is hardened in osmic 
acid, on the other hand, the arched border is preserved, the outer 
third of the cell contents is somewhat more coarsely granuled, and. 
more darkly stained than the remainder, the latter effect not by any 
means due to the greater ease with which the acid attains to that 
portion of the cell. Rarely did the use of this reagent betray the 
absence of the arched border or the apparent presence of a peripheral - 
cell-wall. At the same time the division of its contents into muci- 
gen and protoplasm not coinciding with that shown by other reagents. 
was a constant one throughout. A structure closing the mouth of 
the cell and answering to Biedermann’s ‘plug,’ has never been 
observed by me in the stomachs of the many fishes which I have- 
studied, 
1 Archiv fiir Mikr. Anat. Bd. VI., page 519. 
2 Wiener Akad. Sitzungberichte LXX., Bd. IJI., s. 377. 
% Archiv fiir Mikr. Anat. Bd. XVIII., page 408. 
