142 INTERNAL SECRETIONS OF THE OVARY 



form and constitute the bulk of the sterihzed ovary. Im- 

 mediately after irradiation of the adult, the small follicles be- 

 come atretic without, however, undergoing complete degenera- 

 tion; the larger follicles (with the dosage used] survive and may 

 eventually ovulate. Thus mice may become pregnant up to 



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Fig. 48. — Ovary of Mouse sterilized at Birth. 



This shows an abnormal condition of luteinization found in a 

 small percentage of sterilized ovaries. 



some ten days after the application of a dose of X-rays suffi- 

 cient to result in complete sterility later. The remaining tissues 

 of the smaller follicles become entirely disorganized, and the 

 ovary ultimately consists of a more or less uniform tissue 

 derived from granulosa cells. Small anovular follicles are also 

 present in the ovaries of the irradiated adult. They are formed, 

 however, not by proliferation from the germinal epithelium, but 

 by the degeneration of the ovum and the growth of the mem- 



