352 INTERNAL SECRETIONS 



and masculinization having been for Sand an incentive to 

 carry out experiments upon the simultaneous implantation 

 of both glands, and he started on these in 1914. Afterwards 

 similar experiments were performed by other investigators 

 on mammals and fowls, especially by Pezard, Goodale, Moore 

 and Minoura (in Lilhe's laboratory), Zawadowsky, and by 

 Lipschiitz and his co-workers, Krause and Voss. Most of these 

 experiments gave full support to the conclusions of Steinach 

 and Sand. 



I. The Antagonism between Testis and Ovary. 



We learned in Chapter VI. that there is a certain antagonism 

 between the male and female sex glands. We discussed the 

 question whether sex characters which are favoured in their 

 development by male sexual hormones, could be inhibited 

 by female sexual hormones, and vice versa. The antagonism 

 between the male and female sex gland was a subject of dis- 

 cussion also in another sense. According to Steinach (1916) 

 an ovary which had been implanted in an ordinary male 

 guinea pig, and a testicle which had been implanted into an 

 ordinary female, will not "take" and will not continue to 

 function in the new host, but will finally undergo resorption. 

 A similar statement was made about the guinea pig by Athias 

 (1915). Numerous experiments have been made by Sand 

 (1918) on rats and guinea pigs, the result always being a 

 negative one. Any parts of the graft which were still present 

 were found to be in a state of degeneration. 



According to Steinach and Sand this antagonism between 

 the male and female gonad can be overcome if the host is 

 previously castrated and both testis and ovary are simul- 

 taneously engrafted into such a sexually "neutralized" 

 organism, as Steinach says. But even by this method Steinach 

 did not succeed as well as in ordinary experiments with 

 testicular or ovarian grafts, the number of successful experi- 

 ments with simultaneous implantation being much smaller 

 than those with ordinary crossed or heterosexual trans- 

 plantation. According to Steinach, in simultaneous trans- 

 plantation the graft does not survive so long as in an ordinary 

 transplantation, and he explains this as due to the antagonism 

 between both glands persisting to a certain degree also in the 

 previously castrated host. In the experiments of Sand there 



