The Chromosomes of Euschistus variolarius, Euschistiis serviis etc. 505 
also, and the theoretical deniands of all the above three combinations 
are in accord with the facts of pure variolarius to a certain extent, for 
tliey theoretically demand that the character shall be a constant feature 
of the sex to whicli it is hniited. 
The three formulae are based on the following assuinptions: 
Formula No. 1. The male is homozygous for the white wings factor, 
and the female is without this factor. 
Formula No. 2. The male is homozygous for the white wings factor, 
and the female is heterozygous for this factor. 
Formula No. 3. Both male and female are homozygous for the 
white wings factor. 
As the genital spot of variolarius is a male character, instead of a 
female character, Goldschmidt’s scheme must be adapted as follows: 
First: The factor for the spot must be hnked with A instead of 
G (A' instead of G'). 
Seeon d: G must dominate A instead of the reverse. 
Third: The male must be heterozygous for the female sex, instead 
of the female being heterozygous for the male sex. 
To test the worldng of formula No. 1 for pure variolarius, we must 
make the female, instead of the male, homozygous for the factors for 
the genital spot, for No. 1 assumes that the sex that is homozygous for 
white wings, is homozygous also for sex, thus: $ G G A' A' x G g A A. 
This formula obviously will not fit variolarius, for the spot is a con- 
stant male character and therefore the male must be either heterozygous 
or homozygous for the spot factors. 
To test the working of formula No. 2 for pure variolarius we must 
make the female (instead of the male) homozygous for the factors for 
the genital spot, and the male (instead of the female) heterozygous for 
the spot factors, thus : $ G G A' A' x G g A' A. 
' This formula would not work for variolarius, because half the males 
and half the females from such a pair would be heterozygous for the spot 
factors, and 25 per cent of the males from these heterozygous pairs would 
be without the spot. 
Formula No. 3 when applied to pure variolarius, works out as follows: 
? 
c? 
Gg A'A' 
GA' 
gA' 
Soma G G A' A' 
Gametes G A' 
X 
Zygotes G G A' A' (no spot) 
G g A' A' (spot). 
Archiv f. Zellforschung. XII. 
33 
