THE URIXOGEXITAL SYSTEM 



399 



low irregular projections into the stroma, or the latter begins to 

 penetrate the ovigerous layer at irregular distances so as to 

 produce elevations. This condition is well illustrated in Fig. 

 229. 



In the course of development the ovigerous layer continually 

 increases in thickness, and the projections into the stroma form 

 veritable cords of ovigerous tissue, which correspond to the 



i^s^^iS: 



^^ 





Fig. 230. — Cross-section of the ovary of a fledgling of Numenius ar- 

 cuatus 3-4 days old. The germinal epithelium is below. (After 

 Hoffmann.) 

 s. c, Sexual cords. 



cords of Pfltiger in the mammalian ovary. The cords carry 

 the primitive ova with them. The surface of the ovary also 

 begins to become lobulated by the extension of the stroma tra- 

 beculae. Successive stages in the growth and differentiation of 

 the primitive ova occur from the surface towards the inner ends 

 of the ovigerous strands. Fig. 230 represents a section through 



