414 R. S. CUNNINGHAM 
probably is important in relation to other activities, or poten- 
tial activities, of these cells. No further conclusions can legit- 
imately be drawn from these observations at the present time. 
The ovary 
The cells covering the ovarian ligaments in the rabbit are 
the ordinary, normal, flat mesothelial elements, but at the point 
of attachment these cells pass by rather an abrupt transition 
into the cuboidal cells which constitute the investiture of the 
ovary proper. These cells, commonly known as the germinal 
epithelium of the ovary, are cuboidal in shape and have clearly 
defined, sharply staining nuclei. They seem to rest upon a 
very definite basement membrane and the nuclei are placed in 
general about midway between the surface and the base. 
When vitally stained these cells stored the dye in the infranu- 
clear zone, but only in relatively small amounts in comparison 
with the amounts which were taken up at the same time by the 
clasmatocytes and other cells commonly known as the more 
active in their reaction to the vital dyes; so that in lightly stained 
rabbits there were very few granules to be seen in these cells, 
not more than were found in the cells of the peritoneum generally. 
An increase in the amount of stain given caused a greater increase 
in the amount of dye which was stored by the cells covering the 
ovary, and a very prolonged course of staining produced an 
astonishing picture; the amount of dye in the cells increased 
very greatly until the bases of the whole layer seemed entirely 
filled with the dye (fig. 1). A more accurate description of the 
vitally stained germinal epithelial cells is given from one experi- 
ment that demonstrates especially well the very large amount 
of dye that can be stored: the cells of the germinal epithelium 
varied considerably in size and shape, usually they were cuboidal 
with a tendency to columnar form, the outer border occasion- 
ally tended to be rounded and to show slight indentations be- 
tween the cells. The nuclei were relatively clear and stained 
well. They were located near the center of the cell, but there 
was aslightly wider zone between the nucleus and the basement 
