348 DR FOULIS ON THE DEVELOPMENT OF THE OVA, ETC. 
thus by degrees come to be more or less deeply imbedded in the vascular 
stroma. From the plan and mode in which these changes take place it is 
evident that the several epithelial masses must be connected with each other 
in a plexiform fashion, and consequently that the ovary at this period of deve- 
lopment is composed of a framework of connective tissue, the meshes of which 
communicate freely as in a cavernous tissue. Some, and sometimes many, 
among the imbedded epithelial cells become conspicuous by their size and the 
size of their nuclei, as we have already seen to occur amongst the superficial 
epithelial cells. Other cells remain of small size, and surround the larger cells 
as a kind of epithelium. The connective tissue stroma between the imbedded 
masses of epithelial cells constantly undergoes increase, and especially grows in 
between the several egg cells with their epithelial investment. Thus each 
epithelial ball is divided by these ingrowing vascularised trabecule into as 
many cavities as it contains egg cells. 
In describing the ovary of a newly born child, WaLDEYER thus states, in 
reference to its tubular structure, “One sees long branching formations in the 
form of tubes, anastomosing with each other, as VALENTIN first described, and 
lying separate from each other at considerable distances. They pass upwards 
opening with narrow mouths into the epithelium, and appear as direct tubular 
gland-like processes of it. 
“ At the time in which the tubes described by PFLUGER exist, that is, as far 
as I can find, from the ninth month till a short time after birth, they present 
the structure ascribed to them by PriLicer, with the exception already men- 
tioned, that there is as little of membrana propria in them as there is in the 
primary follicles. In the tubes, and mostly in the middle of them, as PritcEr 
described, we meet with egg cells distinguished by their size and form, often 
immediately concatenated one behind the other. Whether in the tubes new 
egg cells are formed, I cannot decide; but I think it likely, because here, as 
well as on the surface epithelium, some epithelial cells may develope into egg 
cells. Division of the egg cells in the tubes PFLUGER seems to have observed, 
but I have not seen it in fresh specimens.” 
Follicles are formed from the tubes as well as from the egg compartments, 
directly through the growth of interstitial tissue. At the lower end of the tube, 
as may be well explained from the want of a membrana propria, interstitial 
tissue grows into the tubes and encloses the individual egg cells along with a 
portion of the not fully developed epithelial cells which surround them, and im 
this way primary follicles are produced. 
In summing up WALDEYER thus remarks :— 
“ Ag the chief result of my investigations, it must be stated that both the 
egg and the follicular epithelial cells are derived directly from the germ epl- 
thelium. There is a reciprocal growth of vascular connective tissue and germ 

