GENETICS PURPLE EYE COLOR DROSOPHILA 



283 



TABLE 7 



The B. C. offspring given by the Fi ivild-type daughters, from the outcross of a purple 

 vestigial male to a wild female, when back crossed to purple vestigial males 



other internal and external factors not yet analyzed. The best 

 that can be done in correction is to calculate mean values from 

 as many experiments as possible where none of the recognized 

 causes of variation are especially active and thus obtain a sort 

 of composite picture of the 'normal' condition. 



