THE HORMONES IN HUMAN REPRODUCTION 



and Otfried Fellner in Vienna, found that a really potent 

 preparation could be made by extracting the ovary with fat 

 solvents (alcohol, ether, acetone). Their products readily pre- 

 vented castrate atrophy, developed the infantile uterus, and 

 enlarged the mammary glands. In the last year or two before 

 the War of 1914-1918 these results were refined and stand- 

 ardized by several workers, the best work being that of Robert 

 Frank of New York and Edmond Herrmann of Vienna. 



The sum total, then, of twenty years of investigation was 

 the demonstration that there is a substance in the ovary in 

 general, in the corpus luteura, and in the placenta, which has 

 the property of causing growth of the uterus of the infantile 

 animal and of preventing castrate atrophy in adult animals. 

 The relationship of this substance to the estrous cycle and to 

 menstruation was decidedly a problem for the future, and 

 its presence in so many tissues hindered rather than helped 

 the effort to untangle the specific endocrine functions of the 

 ovary and of the corpus luteum. 



The Vaginal Test; Isolation of the Hormone 



During the war the European laboratories dropped such 

 problems as this, but in the United States the discovery (or 

 rather, rediscovery and clarification) of the vaginal cycle of 

 rodents by Stockard and Papanicolaou turned the work in 

 another direction. I mentioned in Chapter III that Edgar 

 Allen in 1922 described a similar cycle of vaginal changes in 

 the mouse. Allen was very much impressed by the striking 

 coincidence of the peak of the vaginal changes with the pres- 

 ence of mature follicles in the ovary. This led him to consider 

 the possibility that there is a hormone in the follicles and par- 

 ticularly in the follicle fluid. The hypothesis that the special 

 events of estrus are due to a secretion of the follicle, rather 

 than of some other element of the ovary, was already widely, 

 if somewhat vaguely entertained, because various observers 

 had noticed that the mature phase of the follicles is closely as- 



{ 82 } 



