Basil C. H. Harvey 211 
I have been able to confirm his observations, seeing them frequently in 
parietal cells, occupying the intracellular canal system, or contained 
in vacuoles, or sometimes, also, apparently in the cytoplasm itself, al- 
though in the latter case it must be borne in mind that they may be in 
extremely small ramifications of the intracellular canals. They do not 
appear to have any association whatever with the chief cells. 
A few parietal cells appear in all my preparations of material fixed 
in aqueous bichromate solutions, which take a yellowish brown or yel- 
lowish green color with this fixative and take no further stain whatever 
with acid fuchsin, orange G, Ehrlich’s triacid mixture, eosin, mucicar- 
mine, muchematein, neutral gentian, or paracarmine. With copper- 
chrome-hematoxylin they stain like other parietal cells but give up the 
stain very readily, so that in sections properly differentiated they are 
unstained with this method also. They are unaffected by hydrochloric 
acid or ferricyanide of potassium even after prolonged exposure, and 
they do not give the iron reaction of MacCallum. They do not blacken 
in osmic acid nor take any stain with Sudan III. In material fixed in 
solutions which do not contain salts of chromic acid they do not appear, 
the parietal cells being nearly uniform in color and staining reactions. 
Occasionally they present the full and rounded outline common to 
parietal cells, but many are irregular in shape and many are shrunken. 
Their nuclei are spherical and contain a normal amount of chromatin 
staining in hematoxylin. The karyoplasm is yellowish green. The 
cytoplasm contains fine granules which stain in hematoxylin but give up 
the stain much more readily than the granules of other parietal cells. 
They retain it, however, more firmly than the cytoplasm about them, so 
that in sections stained with this method there sometimes appear cells 
in which the cytoplasm is yellowish green while the granules contained 
are black. Cells somewhat similar to these were described by Popoff, 98, 
in material taken from stomachs in inflammatory conditions and fixed in 
Flemming’s fluid. He reports similar staining reactions, but found in 
the cells karyokinetic figures and net formations which I was quite un- 
able to find in my preparations, although I employed the methods which 
he recommends. These peculiar parietal cells resemble very closely the 
chromaffine cells described by Kohn, oz, in the suprarenal gland, the 
glomus caroticum and in various parts of the sympathetic nervous system. 
Their staining reactions are similar, the most important one, namely, 
the selective affinity for salts of chromic acid, being very distinct in 
my preparations, so that the parietal cells are separated into two classes 
by it. The granules of these cells in the stomach seem to possess 
