514 MR. F. E. BEDDARD ON THE DEVELOPMENT AND [ Dec. 7, 
one cell thick, but the nuclei of its constituent cells are so crowded 
together that it is not easy to be certain upon this point. The- 
outlines of the follicular cells are in many places plainly visible, and 
irregular processes (Plate LIII. fig. 6) project from these cells toward 
the interior of the mass. This may very well be owing to the 
shrinking of the central mass of cells, and the consequent breaking 
away of its connection with the peripheral epithelium. A comparison 
of the complete series of sections through the developing ovum (the 
section fig. 6 is towards the middle of the series) shows that, 
whether or not there is a connection between the entire periphery of 
the central cells and the follicular epithelium, there certainly is such 
a connection throughout a limited area lying on that side of the ovum 
which is nearest the external surface of the ovary, a little above (or 
below) the pedicle which unites the germinal epithelium with the 
ovum. In this region the nuclei were more abundant and crowded 
together than in the central cells of the mass, and were of uniform 
size and rounded form ; in fact they show an exact similarity to the 
nuclei of the follicular epithelium, which in this stage, as already 
mentioned, forms a distinct layer. The mass of cells which connects 
the follicular layer with the central cells is therefore closely similar 
to the follicular layer, and has the appearance of a proliferation and 
growth inwards of that layer. The central cells, as in the previous 
stage, have nuclei of varying size ; some are long and oval, and others 
shorter and more spherical ; the latter resemble in every particular 
the nuclei of the surrounding follicular layer. 
A characteristic feature of this stage is the commencing formation 
of yolk, which is visible here and there (figs. 27-31) in the cells of the 
central mass, and in the form of droplets of homogeneous appearance 
and varying size. ‘This formation of yolk is not confined to the 
central cells, but is recognizable also in the cells which make up the 
follicular layer. 
Here and there among the central cells are homogeneous masses, 
evidently the same as those referred to in the description of Stage I. 
as a probable resultant of the breaking-down and fusion of certain of 
the central cells. These masses were, however, much less developed 
than in the earlier stage. 
This stage is evidently, from the facts above narrated, in a further 
condition of development than that which I have termed Stage I. ; 
this is also shown in the gradually-advancing separation of the peri- 
pheral layers from the germinal epithelium of the ovary. 
In the earlier stage the pedicle which unites the epithelial layers 
with the germinal epithelium on the surface of the ovary is not only 
very thick, but composed almost entirely of germinal epithelial cells 
in a state of active multiplication. The stroma of the ovary had 
barely penetrated into this mass of invaginated germinal cells. 
In Stage II. the body is just as near to the surface of the ovary, 
and there is a shallow depression on the surface of the ovary corre- 
sponding in position to the centre of the pedicle of attachment, which 
would appear to be the remains of the invagination of the germinal 
epithelium. The activity of the germinal epithelium has, however, 
