SEX INHERITANCE 127 
intersexuality appears. Externally the daughters 
_are “almost indistinguishable from normal males.”’ 
The instincts are entirely male and the moths try 
unsuccessfully to mate with females. The gonads 
look like testes, but show in sections a mixture of 
ovarian and testicular tissue. A step further and 
the daughters would be completely transformed into 
males. The next cross gives this final stage. When 
Jap. O male is crossed to any race of European 
female, only males are produced, 7.e., all the 
daughters become sons. 
The reverse picture is given by those combinations 
in which the intersexes are sons partly changed 
over into daughters, a condition that Goldschmidt 
terms male intersexuality. The wings are generally 
streaked with white and in the extremest type only 
a few spots of the brown characteristic of the male 
appear on the wing-veins. The testis may contain 
some ovarian tissue, but the changes in the gonads 
do not appear to run parallel to those seen on the 
surface. 
The explanation that Goldschmidt offers for these 
intersexes is entirely different from the explanation 
that is demonstrated for the gynandromorphs of 
Drosophila. He accepts the chromosome theory of 
sex determination, and applies it to the present 
case on the basis that the female is heterozygous 
for the sex chromosome Mm (ZW), and the male 
hymozygous MM (ZZ). In addition, however, 
Goldschmidt adds another set of sex-determining 
factors that he calls FF (inclosing them in brackets), 
