44 Psyche [March 
The first filial generation (Fi) consisted of 3 winged males 
and 44 wingless females. 
The second filial generation (F.) was composed of 2 
winged males and 25 wingless females. 
The third generation (Fs) contained 1 winged male, 1 
wingless male, and 12 wingless females. 
Eight of the 12 wingless females of the Fs generation 
were kept virgin, while three females were mated to the 
winged male. A single female was mated to the wingless 
male. 
In the Fi from wingless female x wingless male one naked 
wingless female pupa was produced. It died before maturity. 
Three virgin wingless females produced 14 wingless fe- 
males. 
In another vial one virgin wingless female produced 19 
wingless females. 
Again 3 virgin wingless females produced one wingless 
female. It died in the cocoon. 
The three wingless females mated to the winged male 
produced 3 wingless females which died in their cocoons. 
A wingless virgin female produced 9 wingless female 
pupse. These I removed from the cocoons alive. 
In all, wingless females x winged males produced 6 winged 
males, 1 wingless male and 84 wingless females. Wingless 
females x wingless males gave one wingless female. Virgin 
wingless females produced 33 wingless females. 
Conclusion . 
From the fact that virgin females in general produced 
females, we see that we are dealing with a mode of sex 
determination differing from the Apis type which must be 
worked out before the question of the inheritance of wings 
may be comprehensively attacked. Could I have been dealing 
with a parthenogenetic strain or has change of conditions 
produced a functional difference in reproductive mode? It 
is hoped that someone, working where suitable food supply 
is available the year round, may take up with Scleroderma 
this interesting problem of sex determination and its allied 
question of wing inheritance. 
