DEVELOPMENT OF THE OVARIES AND OVA. 



195 



epithelial cells, enclosing a variable number of them, which 

 thus by degrees come to be more or less deeply imbedded in the 

 vascular stroma. At c, fig. 197, such shoots of the connective 

 tissue are seen, and at d d epithelial cells either imbedded or 

 in process of becoming so. 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 is com- 

 posed of a framework of vascular connective tissue, the meshes of 



Fig. 197. 



Fig. 197. (Fig. 11, Plate ii., of my Treatise.) Vertical section of the 

 ovary of a human foetus at the thirty-second week. (Hartnack 2-7.) 

 a a, Epithelium ; b 6, youngest egg cells lying in an epithelial stratum ; 

 c, connective-tissue trabeculas that project into the epithelial layer ; 

 e e, primordial follicle, with an investment of small connective-tissue 

 cells ; /, groups of epithelial cells (egg balls) that have already become 

 imbedded, with a few subjacent and larger cells (primordial eggs) ; g, 

 granule cells of M. His. 



which communicate freely as in a cavernous tissue. M. His (52) 

 and Kolliker (59) have already called attention to the peculiar 

 cavernous structure of the foetal ovary, though undoubtedly 

 without recognizing the mode in which it originates. Kolliker, 

 however, quite correctly refers the formation of the several 

 follicles to the continuous growth of connective-tissue septa 



Ktween the cells of the epithelial cell clusters, to which he 

 :, 



