504 
Katharine Foot and E. C. Strobell 
He assumes that F and G are linked, that M and A are linked, and 
that m and a are linked, and expresses this by Amting bis formnlae as 
füllows : 
$ (F G) (F G) (M A) (ni a) 
c?(FG) (FG) (MA) (MA). 
He simpUfies these forraulae by dropping F and M, tlius: 
? G G A a 
cJ G G A A. 
He designates a inutation in the feniale secondary sexual cliaracter 
(the above-mentioned tvliite wings, for example) by G', and assumes that 
G'is dominant to G. 
He assumes furtlier that A is dominant to G. (»A über G epista- 
tisch ist.«) 
Applying liis scheine to the case of CoUas, Goldschmidt shows 
that in three different combinations of his theoretical factors, the ex- 
pected results are in accord with Gerould’s facts: 
First: On the assumption that the wild feniale CoUas is heterozy- 
gous for the factor for white wings, and that it is absent in the male. 
Seeon d: On the assumption that the male is heterozygous for 
the factor for white wings, and that it is absent in the feniale. 
Third: On the assumption that both male and feniale are heterozy- 
gous for the factor for white wings. Although in this last case the ratio 
of white or yellow wings in the feniale is not in accord with the demands 
of his forniula, he believes this discrepancy will be corrected by more 
data. 
On page 84 Goldschmidt gives three more combinations of his 
theoretical factors; these reniaining to be tested by experimental bree- 
ding. 
These three combinations theoretically demand that all the females 
should have white wings, and in these cases, therefore, white wings are 
an exclusively feniale character, for they are characteristic of all the fe- 
males, just as the genital spot of variolarius is characteristic of all the 
iiiales. It is evident, then, that if Goldschmidt’s scheine can theoreti- 
cally explain the results of our cross-breeding experiments with Euschistus, 
one of these three combinations must be used, for no scheine can be of 
valiie for the variolarius hybrids that is not ajiplicable to the pure form 
