370 B. F. KINGSBURY 



showing their development, so that it is somewhat difficult to 

 judge of the evidence — aside from the interpretation of the pecu- 

 liar medullary follicles of younger ovaries — that lead them to 

 regard these as quite distinct from the follicles of the earlier 

 period. Sainmont's figures (4 to 9) appear to me far from con- 

 vincing. In their description their resemblance to the medullary 

 follicles is pointed out and the similarity in their mode of ' degen- 

 eration. ' They differ in the presence of a better developed theca 

 and the relation and character of the interstitial cells. 



As in their formative period — as I interpret it — -these follicles 

 are characterised by their great irregularity and the numerous 

 ova usually contained. This appears in figure 13 of a single sec- 

 tion, and more so in a model made from a section of the same 

 ovary. In between these follicles occur numerous cords of cells 

 (which -were reproduced in part) and strands of interstitial cells- 

 (not shown in the model). The stroma forms a well defined 

 theca for the follicle and it is there that the interstitial cells chief- 

 ly occur. Two of the uTegular pluri-ovular follicles are drawn 

 separately (figs. 31 and 32). Their irregularity is clearly apparent 

 from these. The cords of cells are apparently vanishing struc- 

 tures — small groups of follicle cells derived from the medullary 

 cords or of cortical origin. In these follicles several ova are 

 contained. 



The approach of sexual maturity is attended by a profound 

 degeneration of the Graafian follicles formed during the pre-sexual 

 period. In ovaries of this stage nearly all the larger Graafian 

 follicles are found to be in some stage of aresia, as illustrated in 

 one of the figures in my paper on the interstitial cells. Eight 

 ovaries of this period were examined. The conclusion of von 

 Winiwarter and Sainmont that the degenerations of this period 

 involve also the primary follicles as well and that the ova of the 

 sexual maturity are derived from a third ' down-growth' from the 

 surface epithelium, renders this period one of marked importance. 

 As far as the material studied by me goes, it has afforded no evi- 

 dence of such a new formation of ova; in nearly all cases an abun- 

 dance of resting or primary follicles in the cortex was found to be 

 present, and it is believed that the primary follicles found in the 



