TABOO AND GENETICS 59 



is originally quantitative, not qualitative — in 

 amount rather than in kind. 



Mating European moths with European, or 

 Japanese with Japanese, produced pure, uni- 

 form sex-types, male and female. But a cross 

 of European with Japanese strains resulted in 

 intersexes. Goldschmidt concluded that (i) all 

 individuals carried the genetic basis for both 

 sexes ; and (2) that these basic factors were two 

 chemicals of enzyme nature. One of these he 

 called Andrase, enzyme producing maleness, 

 the other Gynase, enzyme producing femaleness. 

 Further, (3) since each chemical sex determiner 

 is present in both individuals in every cross, 

 there must be two chemical " doses " of male- 

 ness and two of femaleness struggling for mastery 

 in each fertilized egg. (4) If the total dose of 

 maleness exceeds the total dose of femaleness, 

 the sex will be male, and vice versa. (5) These 

 quantities get fixed by natural selection in a 

 single race which always lives in the same 

 environment, i.e., the doses of maleness and 

 femaleness in a given sex always bear practically 

 the same relation to each other. Hence the 

 types are fixed and uniform. (6) But different 

 races are likely to have a different strength of 

 chemical sex-doses, so that when they are 

 crossed, the ratios of maleness to femaleness 

 are upset. Often they are almost exactly 

 equal, which produces a type half male and half 



