THE HORMONES IN HUMAN REPRODUCTION 



vestigations. He therefore took a castrated female monkey 

 and gave her a course of injections of estrogenic hormone. 

 When he discontinued the treatment, bleeding ensued. In 

 other experiments he removed the ovaries and immediately 

 began daily doses of estrogenic hormone. As long as the 

 hormone was given, there was no bleeding; that is to say, 

 the hormone was able to substitute for the ovary. When it 

 was discontinued, the bleeding occurred. 



The following diagram represents graphically the experi- 

 ments just described. 



Removal of ovaries; estrin deprivaiion: 



ovaries removgd^ ^.f^j-Zil^J^^^""^ 



INTACT ANIMAL CASTRATE ANIMAL \ 



ovAries rg-moved-^^ i^^-estrin ^iven--^ 



INTACT 



C AST RATE \ 



Fio. 24. Illustrating the experiments of Edgar Allen, 1927, 1928. In 

 this and the following 3 graphs the black bars indicate uterine bleeding. 

 These diagrams are from an article by the author in the American 

 Journal of Obstetrics and Gynecology, by courtesy of the C. V. Mosby 

 Company. 



On this basis Allen formulated the estrin-deprivation 

 hypothesis of menstruation, which suggests that natural 

 menstruation, like the experimental bleeding, is due to a 

 cyclic reduction of the amount of the estrogenic hormone 

 available in the body. 



Subsequent experiments done with carefully graded doses 

 of the hormone, including especially those of Zuckerman, of 

 Oxford, have shown that not only total deprivation, but also 



{ 162 } 



