DILUTION EFFECTS IN CERTAIN EYE COLORS 435 



Red heterozygous for vermilion and pink 



A careful examination of the Fi females from vermilion female 

 by pink male failed to show any change produced by the hetero- 

 zygosity of the two factors for vermilion and pink. The results 

 have been given in ^'Further experiments with mutations in eye 

 color of Drosophila,^ but under a different system of nomencla- 

 ture from the one here adopted. 



Pi 



Red heterozygous for eosin and pink 



When the eosin female is mated to a pink male, the daughters 

 are red heterozygous for both eosin and pink but in color are 

 like the normal red. The sons are 6osin, as explained in the in- 

 troduction in the cross of eosin female to white male, because of 

 sex-linkage : 



p eosin 9 Xw^ P — Xw^ P 

 pink cf XW p — p 



* In addition there appeared one red male 



The converse cross produced normal red sons, and females 

 heterozygous for eosin and pink: 



p pink 9 XWp— XWp 



eosin cf Ww^P P 



' Jour. Acad. Nat. Sciences, Philadelphia, November, 1912, p. 338. 



