289 



zygous and 39 heterozygous. Table VI, the reciprocal cross of Table V, 

 shows a result of 14 homozygous and 16 heterozygous males. 



A sum total of all the results of Tables III-VI gives 84 homozygous 

 F-2 flies and 169 heterozygous, making a ratio of one to two, which agrees 

 with the calculated ratio. 



I am indebted to Dr. R. R. Hyde for material and helpful suggestions. 



TABLE III. 

 Pi. Scarlet Female by Wild Male. Results of Crossing Wild Type F2 Female Flies to Scarlet Males. 



19—11994 



