458 T. H. MORGAN AND C. B. BRIDGES 



eosin vermilion 9 Xw^vP — Xw'^vP 

 ^ white verm, pink cf X w v p — p 



Fi female Fi male 



X w« V P X w« V P 



X w v p p 



white-eosin compound eosin vermilion cf 

 vermilion 9 heterozygous heterozygous for pink 

 for pink 



247 186 



The converse experiment, white vermiUon females mated to 

 eosin vermiUon pink males, gave white-eosin compounds ver- 

 milion heterozygous for pink, and white males. The Fi here 

 does not offer as direct a comparison as the preceding, but in 

 F2 below some very interesting combinations occur : 



Pi 



white vermilion 9 XwvP — XwvP 

 eosin verm, pink cf X w® v p p 



331 295 



Gametes ofFi9 Xwvp — XwvP — Xw^vp — Xw'^vp 

 Gametes ofFicf Xwvp — XwvP — p P 



F2 females F2 males 

 Xwvp XwvP Xw'^vp Xw^vP Xwvp XwvP Xw^vp Xw^vP 

 Xwvp Xwvp Xwvp Xwvp p p p p 



Xwvp XwvP Xw^vp Xw^vP Xwvp Xwvp Xw^p Xw^vP 

 XwvP XwvP XwvP XwvP P P ' P — P 



As the zygotic formulae above show, half of all the flies (eight 

 classes) should be white. The colored females are of three kinds, 

 white-eosin compound vermilion, white-eosin compound vermil- 

 ion heterozygous for pink, and white-eosin compound vermihon 

 pink. Likewise the colored males are of three colors, eosin- 

 vermilion, eosin-vermilion heterozygous for pink, and eosin-ver- 

 milion pink. The separation of the males is exactly the same 



