CHAPTER V 



A HORMONE FOR GESTATION 



IF this were a detective story, not merely a story of 

 detection, the reader would at this point be directed to 

 turn back to pages 41-44, in which (he would solemnly 

 be informed) he will find all the clues necessary to solve the 

 great Corpus Luteum Mystery. Having reread those pages 

 and having inspected the photographs of the corpus luteum, 

 Plate IX, he will be in possession of all the information that 

 enabled Louis-Auguste Prenant of Nancy in 1898 to suggest 

 that the corpus luteum, subject of so much previous con- 

 jecture and so little fact, is actually an organ of internal 

 secretion. This guess, I admit, required sharp wits. Today 

 every reader who has studied biology ought to get the same 

 idea when he sees this small but vivid organ, walled off from 

 the rest of the ovary by its fibrous capsule, drained by no 

 secretory duct but obviously equipped with a rich network 

 of blood vessels, and composed of large and characteristic 

 cells resembling those of the adrenal gland. Seen under the 

 microscope as pictured in Plate IX, C, this arrangement 

 fairly shouts "I am a gland of internal secretion" ; to recog- 

 nize that fact forty-four years ago was a real feat of scien- 

 tific detection. 



But even in novels of crime the sleuth's clever guess must 

 be followed by careful accumulation of evidence for the 

 jury; still more is this the case when the object of detection 

 is the function of an important gland and the seeker's reward 

 a valuable addition to scientific knowledge and human 

 welfare. 



I do not pretend to write this chapter in cool detachment. 

 Its theme-word progesterone has for me connotations that 

 will never be found in the dictionary. In the first place I 

 invented the word myself, as far at least as the letter "t," 



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