354 



CALVIN B. BRIDGES 



TABLE 11 



The F2 offspring of two Fi mass cultures from the outcross of an Fi cherry male 

 heterozygous for whiting {ex Ml 19) to cherry female 



CREAM III 



In a culture which was part of an experiment on lethal lb 

 (Morgan and Bridges, '16) Miss E. M. Wallace found (February 

 27, 1914) a few females which were much lighter in eye color 

 than their white-eosin sisters. Following my suggestion that 

 this color might be a cream similar to cream a or cream II, these 

 females were given me for experimentation. I outcrossed one 

 of them to an eosin male of pure stock. The Fi males (table 12) 

 showed that this female had carried yellow and white in one X 

 and eosin in the other, this being the condition expected from 

 her parentage. The cream was seen to be recessive, since all of 

 the Fi flies were standard in color, and not sex-linked, since it 

 did not appear in the sons of the cream mother. 



An Fi mating was made between an eosin female and an eosin 

 male, since by this means both. yellow and white could be elimi- 

 nated from the experiment. In F2 the cream color reappeared 

 but in numbers rather fewer than the expected quarter (table 

 12). In appearance this cream III was very nearly as light as 

 the homozygous cream II. 



TABLE 12 



The Fi and F2 offspring from the outcross of a new cream (cream III) 9 to an 



eosin cf 



