66 P. C. Williams 



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DISCUSSION 



Amoroso: Before putting Mr. Williams' paper open to discussion 

 I would like to ask him one question. Are these atretic phenomena 

 equally well expressed in the adult ovary as in the immature ovary? 



Williams: That I do not know. 



Zuckerman: Is the first sign of atresia in the normal ovary invariably 

 in the granulosa? A paper published about two years ago discussed the 

 nature of the atretic process in the X-irradiated ovaries as compared 

 with the normal, and the suggestion was made that X-irradiation, like 

 any noxious stimulation, began a process of atresia which started with 

 degeneration of the oocyte. An abortive division first occurs. I under- 

 stood that in the atresia which occurs in the normal ovary, changes in 

 the oocyte began after changes in the granulosa. 



Williams: I do not know which comes first. 



Parkes: You seem to have very well-preserved eggs in some of the 

 follicles which have become atretic. Is that usual under those conditions? 

 One expects to find rather a bad looking egg inside an atretic corpus 

 luteum. 



Rowlands: I can confirm, from my limited experience with the guinea 

 pig ovary, that the egg does seem to be preserved in a good condition 

 for a very long period of time in an atretic follicle and the zona 

 pellucida remains recognizable in a corpus luteum atreticum for a large 

 part of the pregnancy. 



Strauss: I would like to ask if you think that antrum formation is 

 dependent on an endocrinological process ? 



Williams: Yes, I think it certainly is. 



