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Further Experiments with the Mutant, Scarlet, from 

 Drosophila Repleta. 



HoBART Cromwell. 



The mutant, scarlet, from Drosophila repleta, was first described 

 by Hyde in the American Naturalist, 1914, Vol. 49, p. 183. This new 

 eye-color was found to be a recessive Mendelian unit, giving a ratio of 3 

 to 1 in the F2 generation. In order to familiarize myself with Mendel- 

 ism, I undertook to determine whether or not the black-eyed flies of the 

 F2 generation were in the ratio of one homozygous to two heterozygous 

 as the Mendelian formula demands. 



The following tables give the results of the crosses between sera-let 

 and the wild stock. All the Fi flies had black eyes like those of the 

 original wild parents. These were then inbred in mass culture, as is 

 shown in Tables I. and II. 



TABLE I. 

 F3 Flies of the Cross, Scarlet Female by Wild Male. 



