l62 INTERNAL SECRETIONS OF THE OVARY 



same effect has been observed (500) when the injected immature 

 animals have been sterihzed by exposure to X-rays and there- 

 fore possess no Graafian folhcles. In such cases the production 

 of cestrus, and therefore of oestrin, must have been dependent on 

 the stimulation of the tissue of the irradiated ovary. In the 

 ovary of the sterilized adult, no histological changes were 







r 



>4l^. 





Fig. 61. — Group of Tubal Ova following Super-ovulation 



DURING precocious CEsTRUS IN THE MoUSE. 



Forty-eight ova were present in this tube. (From Smith and Engle. 



observed following the injection of anterior pituitary suspen- 

 sions, but the duration of cornified vaginal smears was 

 prolonged. 



The only important difference between the work of Zondek 

 and Aschheim and that of Smith and Engle seems to be that 

 whereas the latter authors always found that normal follicular 

 maturation occurred, the former found that atretic corpora lutea 

 and blood follicles were also produced. Smith and Engle (581) 

 actually state: ' In contrast to the large number of follicles 

 which are found undergoing atresia in the normal animal, we 



