THE HORMONES IN HUMAN REPRODUCTION 



old hereditary pattern of the body does not yield readily to 

 these upstart hormones. 



As will be understood from the introductory discussion of 

 castrate atrophy (at the beginning of this chapter), these 

 same effects of estrogens occur in adult animals that have 

 been deprived of their ovaries, just as in immature animals. 

 In short, the action of estrogens is to bring up the immature 

 uterus to the full adult stage, and then to keep it up, ready 

 and waiting for the further changes that will be imposed upon 

 it by the action of the corpus luteum. All this has been amply 

 confirmed in the highest animals ; in monkeys by direct experi- 

 ment on immature and castrated animals, in human patients 

 by therapeutic treatment of women whose ovaries had been 

 removed for surgical reasons. 



We once saw a fantastic outcome of estrogen treatment. 

 Thomas R. Forbes, while a student in my laboratory at the 

 University of Rochester, tried estrone on some 18-inch 

 female alligators. These creatures were still several years 

 short of sexual maturity, and their oviducts (they have no 

 uteri, being oviparous) were very immature. The heavy 

 dosage of estrone crowded years of development of the 

 oviducts into a few weeks, while the rest of the alligator's 

 body remained small. Before long their bellies began to bulge, 

 they sickened and died. At post-mortem Forbes found the 

 abdominal cavities full of nothing else but coil after coil 

 of hypertrophied oviducts, which had pushed the liver up 

 toward the head, jammed the intestines into the flanks, and 

 finally killed the unfortunate creatures when they could no 

 longer find room for these redundant viscera. It would not be 

 possible (I hasten to add) to produce such tragically dispro- 

 portionate growth in humans or other mammals except 

 perhaps by treatment during the embryonic period. 



In mammals, of course, the vagina shares in all this re- 

 sponse of the reproductive system to estrogenic hormones, 

 and in the rat, mouse and guinea pig it gives tell-tale signs 



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