124 SEX INHERITANCE 
nucleus should give rise to male parts. Another 
suggestion was made by Morgan, namely that one 
sperm fuses with the egg nucleus and gives rise to 
female parts, while another sperm that has also 
entered, develops independently and produces male 
parts (Fig. 36 K, B). It is known that more than 
one sperm may enter the egg of the bee. A third 
explanation is offered by the theory of elimination 
of a daughter X-chromosome (Fig. 36 K, C), as 
in Drosophila. This explanation would apply in 
those cases where the bees were hybrids, provided 
the racial characters that were involved in the 
Eugster bees and in von Engelhardt’s bees are 
carried by the sex-chromosome—a point not yet 
determined. 
INTERSEXES AND SEX 
As first shown by Brake, remarkable mosaics of 
male and female characters are found in hybrids 
between the European and Japanese varieties of 
gipsy moths Porthetria dispar and japonica, when 
the cross is made one way but not when made the 
other way. We owe to Goldschmidt not only a 
most complete account of such hybrids but also of 
hybrids between several Japanese local varieties of 
this moth. A most astonishing series of mixtures 
of male and female characters come to light, not 
as sporadic occurrences, but as regular phenomena 
of the crosses. In his earlier work Goldschmidt 
called these mixed forms gynandromorphs, but his 
