598 CALVIN B. BRIDGES 



white 9 red 9 white cf redd^ 



2 128 86 2 



3 131 157 2 



5 259 243 4 



The cross of white pink females by eosin vermiUon pink males 

 was originally planned only on a small scale for the purpose of 

 making observations on the eye color of the daughters. When 

 there appeared a few matroclinous daughters, the scale of the 

 experiment was increased. However, the color of the males which 

 would correspond to the exceptional females is very close to 

 white, and it would be easy to miss some of them among the 

 normally produced whites. Accordingly, some of the females 

 from the white pink stock were mated to wild males. I raised 

 four cultures, using as the mothers in each case five white pink 

 females. The results show that non-disjunction was wide-spread 

 in that stock and had maintained itself there during the six 

 months (some fifteen generations) between the two crosses. The 

 results are tabulated below: 



Pi 



11 910 845 19 



That it is the same phenomenon here is shown by the results 

 of mating a white daughter (of the seven) to wild males. 



Pi white 9 wildcf 



Fi white 9 red 9 white cf rede? 



3 99 64 3 



Half of these white females should be heterozygous for pink 

 if they really were produced in the manner assumed. One bred 

 to a pink male showed that she was in fact heterozygous for 

 pink. 



Pi white 9 (of the three) pinkcf 



Fi white 9 red 9 pink 9 white cf redcf 



2 70 71 126 2 



