MORPHOGENESIS OF THE MAMMALIAN OVARY 



375 



period can be explained as due simpl}" to the intrinsic conditions 

 of growth. 



The relations of the zones that mark the morphogenesis of the 

 cat's ovary may be illustrated by a series of schemata (text fig- 

 ure 7) wherein schema A indicates approximately the conditions 

 in the 75 mm. fetus, schema D, the zones of the adult ovary. 

 These schemata may also be directly compared with the photo- 

 graphs reproduced as figures 8 to 15. The nomenclature of the 

 ovary has been briefly discussed (p. 357). 



Fig. 7 Schema to illustrate the appearance of the zones in the morphogenesis 

 of the cat's ovary. C.P., primitive cortex; C, cortex (definitive) ; N.E., epithelio- 

 stromal nucleus; N.B., nucleus basalis; Z.I., intermediate zone; Z.P., zona par- 

 enchymatosa; Z.V., zona vascularis. 



In an attempted analysis of the morphogenesis of the mamma- 

 lian ovary it would be necessary to compare the development in 

 small, medium-sized and large animals in detail, in order thereby 

 to eliminate the effects of size, and arrive if possible at the intrin- 

 sic aspects of the organogenesis. Such an analytical comparison 

 of mammalian ovaries has hardly been done. The recent account 

 of Felix of the development of the human ovary, as already 

 sketched, indicates possibilities, and to it, along general lines, the 

 development of the ovary of the cat appears to conform. The 

 existence of 'medullary cords' and Pfliiger's 'egg tubes' must be 

 regarded as of secondary significance as but variations in the 

 mode of growth. The neogenic zone of Felix obviously compares 

 with the primitive cortex of the ovary of the cat. It is to be 

 regretted that the description did not include the important 

 period of development during childhood. 



