368 B. F. KINGSBURY 



primary follicle or medullary cord and in the process of growth 

 simply becomes wrapped around, enclosing ovum and its follicular 

 epithelium of the opposite pole, as well as some of the stroma. 



In support of the above interpretation and as opposed to the 

 reverse one of regressive change by a process of enucleation, may 

 be advanced: (1) the fact that in general the smaller egg cells are 

 less enclosed; (2) that they lie generally more peripherally; (3) 

 that the line of fusion of the investing epithelium may often be 

 detected (figs. 19, 20, 22); (4) that the free egg cells possess in 

 most instances at least a sheathing simple follicular epithelium; 

 (5) 'that degenerating egg cells lying free in the stroma are but 

 seldom encountered. 



Accepting the interpretation above set forth, it can hardly be 

 doubted that these follicles owe their irregular form relations to 

 a compounding of the growth of the stroma and that of the follicu- 

 lar elements. It may be suggested that their peculiarities are to 

 some extent due to an attempt at follicle formation in an ovary 

 during rapid growth; or, put differently, the growth of follicular 

 elements and ovarian stroma in lines at variance with each other 

 prevents the free expansion and uniform growth so characteristic 

 of the adult ovary, so that the growing follicular cords must 

 grow around the ovum and hence come to invest it (figs.^24 and 

 25). The reverse, from the same point of view, might easily be 

 conceived to occur and the follicular cells be stripped off as a re- 

 sult of the pressures and tensions of the stromal growth, and thus 

 the ovum be left naked in the midst of the stroma, producing thus 

 the effect of enucleation without attributing to the ovarian stroma 

 a specific activity in the process. Indeed, from the figures of 

 von Winiwarter and Saimnont, as well as my own observations, 

 this appears frequently to be the case. What chemical corre- 

 lations may likewise be involved cannot be estimated. - 



The follicular structures in the ovary at this period are of very 

 varied form. In order to obtain a three-dimensional view of the 

 relations, a model was made of a portion of an ovary (no. 26) in 

 which folhcular cords, follicles and ova inside the primitive cor- 

 tex are illustrated. The ova shown are in all cases immediately 

 surrounded by their simple folhcular epithelium. Of two of the 



