OVARIAN FOLLICLES IN FERRETS AND FERRET-POLECAT HYBRIDS. 317 
The Post-inseminal Growth oe the Follicles. 
It has been pointed out that the average size of the ovarian follicles of animals 
in full heat, in which no attempt at insemination was made, the first oestrus of the 
season, is ‘3215 mm. 3 , and that the average size of the largest follicles in animals in 
which insemination had been unsuccessfully attempted is '9567 mm. 3 
After insemination, on account of the rapid formation of the secondary liquor 
folliculi, the average size of the largest follicles increases to 17815 mm. 3 , as estimated 
from the largest follicle of each of twenty ovaries (Tables YI— IX), the ova in the 
follicles being either in the first maturation spindle stage or in the first polar body 
stage of development; therefore in a period varying from 19 to 41 hours after 
insemination the follicles increase to over five times their original size. 
After rupture, and before redistension, the average size of the largest follicles falls 
to 7800 mm. 3 , as measured in 14 ovaries in which rupture of the follicles had 
occurred, and in which it was noted that redistension had not recommenced (Tables 
VII-XII). Measurements made upon the largest follicles of 35 ovaries in which the 
follicles had ruptured, closed, and redistended give the average size of the redistended 
follicles as 1'9478 mm. 3 — that is, somewhat larger than the average size of the ripe 
unruptured follicles. 
The redistension of the ruptured follicles may commence 41 hours after insemina- 
tion, but it may not have commenced 10 hours later. The redistension may be 
completed at any time between 61 and 120 hours after insemination. 
Changes in the Follicular Epithelium during the Maturation and the 
Distension of the Follicles. 
At all periods of the growth of the follicles the protoplasm of the follicle cells 
contains a considerable amount of substance which assumes a grey, or greyish-black, 
or bluish-black appearance when treated by iron-hsematoxylin methods, and which 
stains a more or less definite violet under the influence of Benda’s alizarine stain ; 
presumably, therefore, it is of mitochondrial nature. This substance may be either 
in the form of granules or filaments, and the filaments may form a more or less 
definite reticulum. 
In the primitive follicles, in which the follicular epithelium has the form of 
flattened curved plates, the mitochondrial substance is granular, the nuclei of the 
cells are ovoid : their chromatic substance is distributed throughout the bodies 
of the nuclei ; it has the form of spheroids of varying size, of which one is 
usually somewhat larger than the others. The spheroids are scattered irregularly 
in the interior of the nuclei, but it is not possible to say that any definite nucleoli 
are present (figs. 4, 5, PI. I). 
When the follicle cells become cubical or columnar the granules of the cell 
