DILUTION EFFECTS IN CERTAIN EYE COLORS 441 



Pi 



The Fi females and males were exactly alike in color and like 

 the wild flies. An eosin female gave by a vermilion pink male 

 55 red daughters heterozygous for eosin, vermilion and pink and 

 45 eosin males. 



Red heterozygous for white, vermilion, and pink 



When wild red females were crossed to white vermilion pink 

 males the daughters were heterozygous for the desired three 

 factors : 



Pi 



red 9 X W V P— X W V P 

 white verm, pink c? X w v p — ■ p 



Fi females Fi males 



XWVP XWVP 



X w V p p 



red 9 rede? 



104 96 



38 33 



142 129 



The red eyed females are like the wild flies. 



The preceding crosses show that the color of the red eye is 

 not diluted, as far as can be seen, by being heterozygous in one, 

 two or three factors. Whether dilution can be produced by the 

 introduction of heterozygosity for still more eye colors we cannot 

 state, since we have not made up red-eyed flies heterozygous for 

 these eye color factors plus the other eye color factors known to 

 us at present. The evidence seems to indicate that the red eye 

 is too densely pigmented for differences produced by heterozy- 

 gosity to become evident. 



