INHERITANCE OF SEX AND RELATED PHENOMENA 217 
have gone about three-fourths of the way toward the assumption of 
the entire set of female characters. 
Goldschmidt ascribes these results to differences in potency of the sex- 
factors. The European gypsy moth was found in all races to possess sex- 
factors of low potency, whereas in the Japanese races the potency was 
in general higher, but ranged from the lowest to the highest condition. 
Thus males of a moderately strong Japanese race mated to females of a 
Japanese race of slightly less potency give in /’, very low-grade female 
intersexes. When mated to a somewhat less potent Japanese race a 
higher grade of female intersexualism results, and when mated to the 
weakest European race nothing but high-grade female intersexes are 
produced. The highest grade of female intersexualism, the transforma- 
tion of those individuals which are genetically females entirely into 
males, results from matings of females of European races of the lowest 
potency to males of Japanese races of the highest potency. Now if the 
development of sexual characters depends upon the sex-factors acting 
in conjunction with other elements in the genotype, the existence of sex- 
factors or rather of systems of factors might operate in somewhat the 
following fashion. In the female the sex-factor in a heterozygous condi- 
tion acts in conjunction with a set of factors some of which are perhaps 
sex-linked, although the number of chromosomes, 62 in this case, would 
indicate that perhaps most of them were located in other chromosomes. . 
In a heterozygous condition then a certain sex-factor with those factors 
with which it acts produces a female with the female set of secondary 
sexual characters. In the homozygous duplex condition the same sex- 
factor, presumably acting in conjunction with the same set of factors as 
in the female, produces a male with the male set of secondary sexual 
characters. If now there should be variations in the potency of a sex- 
factor, as Goldschmidt assumes, then a strong sex-factor, or a sex-factor 
which would interact more effectively in a given genetic environment 
would have a tendency in the heterozygous condition to throw the reac- 
tion more in the direction of that formerly conditioned by the existence 
of the normal sex-factor in the homozygous condition. Such relations 
would result in the formation of female intersexes, individuals genetically 
females so far as the chromosome constitution is concerned, but develop- 
ing male characters in a degree corresponding to the greater potency of 
the introduced sex-factor as compared with the sex-factor normal for 
the race in question. In case the introduced sex-factor, along with the 
factors with which it normally interacts and which must never be dis- 
regarded, equals in sex-determining power that of the normal sex-factor 
in the duplex condition, then we might expect to get males of the chromo- 
some constitution WZ. This appears actually to be the case in certain 
of the experiments. Similarly a weaker potency of the sex-factor might 
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