THE EXPERIMENTAL PRODUCTION OF 



PSEUDOHERMAPHRODITISM IN 



THE MONKEY* 



MODIFICATIONS of the urogenital tract in the genetically determined female 

 have long been observed and described as occurring in man and domestic 

 animals. Differentiation of accessory sex organs in a genetic female so that 

 they resemble those of a male is termed female pseudohermaphroditism. Ob- 

 viously, such profound changes in structure must have been initiated in early 

 intra-uterine life. The masculinization of female offspring in mammals has 

 been accomplished experimentally by Dantchakoff/ who used sex hormones 

 to develop embryonic heterosexual genital ducts in the guinea pig, and by 

 Greene and Ivy," who produced similar changes in the rat. 



In the experiments to be described in the present paper, masculinization 

 of the female monkey fetus resulted in a striking resemblance to human in- 

 fants who at birth have all the appearance of a male (cryptorchid), but whose 

 subsequent developmental history is such that the question of sex does arise 

 and in whom upon examination a uterus and ovaries are found. 



Material and Methods 



Testosterone propionate was the androgen used. Crystals dissolved in sesame 

 oil in a concentration of 20 mg. per cc. were injected intramuscularly six times 

 a week. The wish to spare the animal an abdominal section at the very begin- 

 ning of the experiment led us to avoid the direct method of Dantchakoff, who 

 introduced pellets of hormone into the amniotic cavity of guinea pig embryos. 

 There were no previous data to indicate dosage in the monkey, so three graded 

 dosages were arbitrarily chosen, 5, 10, and 20 mg. per day. Monkey 05 received 

 5 mg. per dose; monkeys 99 and 77, 10 mg.; and monkeys 96, 59 and 36 the 

 largest amount, 20 mg. Table 1 summarizes for each individual the daily and 

 total amounts of testosterone propionate administered and the time of the 

 initiation and duration of the treatment. 



The rhesus monkey (Macaca mulatta) provides us with a primate laboratory 

 animal in which anatomical and physiological characteristics of the repro- 

 ductive organs are similar to those of man. For the purpose of properly timing 

 the period for injection of the pregnant animal it was necessary in our study 

 to have definite information concerning the beginning of pregnancy. The 



* This work was supported chiefly by grants to the Department of Obstetrics and Gyne- 

 cology, from The John and Mary R. Markle Foundation and the Fhiid Research Fund of 

 Vale University School of Medicine and also aided by a grant from the International Cancer 

 Researclr Foundation to the Department of Anatomy. 



[583] 



