THE HORMONES IN HUMAN REPRODUCTION 



to find a test for whatever hormone one suspects to exist — 

 some sharp-cut characteristic effect that is lost when the 

 gland is removed and that can be restored by giving back the 

 gland in implants or in extracts. At each step of our story in 

 this book such a method has been the key to success. The 

 vaginal smear test for the estrogens, the rabbit uterus test 

 for progesterone, promptly made possible the purification of 

 these substances. If the test is quick and cheap, the results 

 will come that much faster. Berthold's experiment with the 

 cockerels provided an ideal method of testing for a hormone 

 of the male sex gland. Success came to those who followed his 

 lead, putting aside premature efforts to work with slowly 

 growing mammals or to rejuvenate old men. Between 1907 

 and 1927 two or three European investigators reported that 

 they had extracts of the testis which induced growth of the 

 head furnishings of cocks. None of these experiments, how- 

 ever, was fully convincing. Meanwhile the estrogenic hor- 

 mones were isolated and discovered to be soluble in fat sol- 

 vents. In 1927 a graduate student in biochemistry under 

 Professor F. C. Koch at the University of Chicago, L. C. 

 McGee (now a physician in Elkins, West Virginia) applied 

 the new methods of extraction to the tissues of the bull's testis 

 and promptly secured a relatively pure extract that was 

 capable of producing rapid growth of capons' combs (Fig. 

 32). This lead was followed up by a group of workers in 

 biochemistry and zoology in the University of Chicago, 

 including McGee, F. C. Koch, C. R. Moore, L. V. Domm, and 

 Mary Juhn, and by various workers abroad. The successive 

 steps in the purification and identification of the male or 

 androgenic hormones were much like those in the isolation of 

 the estrogenic substances. In 1929, S. Loewe and S. E. Voss 

 of Dorpat (Estonia) and also Casimir Funk and B. Harrow 

 of New York found androgenic substances in human urine 

 from males. The indefatigable Butenandt and his aides then 



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