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THE AMEBIC AN NATURALIST [Vol. XLIX 



with the hope of finding whether or not scarlet was common in 

 this region. I have bred many of the stocks since that time, but 

 so far no scarlets have appeared. 2 



Behavior op Scarlet in Heredity 

 One of the original virgin scarlet females was mated to a 

 scarlet male. The union was fruitful and a pure scarlet race 

 was produced which has bred true since that time. The sexes are 

 easily distinguished, the life cycle is about thirty days, and after 

 long experience I have found it comparatively easy to breed 

 this fly in captivity. 



Scarlet was crossed to a wild stock which had been taken about 

 four months previously in Terre Haute. This stock bred true 

 to black eyes. The flies were studied in mass culture and virgin 

 flies were used in crossing (the sexes were separated every 18 

 hours) . The offspring, which had eyes like the wild stock, were 

 mated in mass culture for the F 2 generation. The following 

 tables give the results from the crosses. 



These tables bring out the fact that the new eye color is a 

 simple Mendelian recessive character since it approximates the 



Hons in this species. In the fall of 1911 a female of D. repleta was taken 

 in the Zoological laboratory at Columbia University and from this a stock 



less difficulty for more than a year. It was comparatively easy to keep the 

 colony going in the same bottle by adding food from time to time but 



observation I examined many hundreds of repletas without finding a single 



