NEW DATA. 



39 



was mated to (red red) sable males and gave 202 wild-type 1 females 

 and 184 eosin vermilion males. Two FI pairs gave the results shown 

 in table 12 (the four classes of females not being separated). 



TABLE 12. PI eosin vermilion 9 9 X sable cf cf . FI wild-type 9 X FI 



eosin vermilion cf cf 



If we combine the data for males given in table 12 with those of 

 table ii, we get the following cross-over values. Eosin vermilion, 32; 

 vermilion sable, 12; eosin sable, 41. 



a ln addition to these expected FI wild-type females there occurred 13 females of an eye-color 

 like that of the mutant pink. So far as was seen none of the FI males differed in eye-color from 

 the expected eosin vermilion. Since the eosin vermilion and sable stocks were unrelated and 

 neither was known to contain a "pink" as an impurity, these "pinks" must be due to mutation 

 of an unusual kind. That these "pinks" were really products of the cross is proven by the result 

 of crossing one of them to one of her eosin vermilion brothers, for she showed herself to be heterozy- 

 gous for eosin, vermilion, and sable. 



FI "pink" (Ref. 51 C) 9 X F! eosin vermilion cf . 



In addition to the combinations of eosin and vermilion, sable also appeared in its proper dis- 

 tribution, though no counts were made. The four smaller classes are cross-overs between eosin 

 and vermilion. Since no "pinks" appeared the color is recessive, and the brother was not hetero- 

 zygous for it. 



Two other "pink" females mated to wild males gave similar results in their sons. 



Fi"pink" 9 X wild cf. 



These FI flies should all be heterozygous for "pink." A pair of wild-type flies which were 

 mated gave a 3 : i ratio wild type 51 to "pink" 18. From the "pinks" which appeared in this 

 cross a stock was made which was lost through sterility. Females tested to males of true pink 

 were also sterile, so that no solution can be given of the case. 



