402 INTERNAL SECRETIONS 



Daphnia atkinsoni, and Sexton and Huxley on the crustaceaa 

 Gammarus chevreuxi, a brackish water amphipod. 



Two points stand out in Goldschmidt's results which are of 

 special importance for us. First, no doubt can be possible as 

 to the conclusion that the factor causing intersexuality and 

 controlling its degree, in the case of the moth, is not the gonad ; 

 and, secondly, that the variability so characteristic in every 

 domain of intersexuality may be understood as a function of 

 time, 



Goldschmidt calls the intersexuality observed in insects 

 a zygotic one, as opposed to the hormonic intersexuality present 

 in mammals and birds. Zygotic intersexuality means that the 

 result is already determined at the moment of fertilization as 

 in insects, whereas in mammals and birds the somatic and 

 psychical characters can be changed by the action of hormones. 

 This terminology of Goldschmidt is not a very fortunate one, 

 as probably also in mammals and birds the result or the degree 

 of intersexuality may already be determined, though not 

 necessarily at the moment of fertilization. The difference 

 between insects on the one hand and mammals and birds on 

 the other is evidently only that in the first case the factor 

 causing the turning over to the other sex is not localized in the 

 sex gland, but rather, as Goldschmidt assumes, in all the cells 

 and tissues of the organism, whereas in the second case the 

 factor may be certainly located in the sex gland and possibly 

 also in some other organ of internal secretion. There is really 

 in both cases a "zygotic" intersexuality. 



It is of great interest to note that Goldschmidt adverts in a 

 certain degree to hormones when explaining the individual 

 phenomena of what he calls zygotic intersexuality in the moth. 

 He assumes that in every individual hormones of both sexes 

 are present, the quantitative relation between the two hormones 

 being constant for every sex of a given race. Intersexuality 

 develops when this normal quantitative relation is disturbed, 

 the quantity of hormones of one sex becoming greater than 

 normal; such a disturbance is caused when crosses between 

 races with different normal quantitative hormone relations 

 occur. Further, Goldschmidt supposes that the time at which 

 the turning over to the other sex takes place also depends on 

 the quantitative relation between male and female hormones in 

 the same individual; the inversion will take place the earlier, 



