NEW DATA. 



73 



A complementary experiment was made by crossing cherry club 

 vermilion females to wild males and inbreeding the FI in pairs. Table 

 54 gives the results of this cross. 



TABLE 54. P\ cherry club vermilion c?d*. 9 9 X mid 

 FI wild-type 9 X FI cherry club vermilion cf cf 



The combined data of tables 53 and 54 give 14.2 as the value for 

 cherry club. All the data thus far presented upon club vermilion 

 (886 cross-overs in a total of 4,681), give 19.2 as the value for club 

 vermilion. The locus of club on the basis of the total data available is 



at 14.6. 



GREEN. 



In May 1913 there appeared in a culture of flies with gray body-color 

 a few males with a greenish-black tinge to the body and legs. The 

 trident pattern on the thorax, which is almost invisible in many wild 

 flies, was here quite marked. A green male was mated to wild females 

 and gave in F 2 a close approach to a 2 : I : I ratio. The green reap- 

 peared only in the F 2 males, but the separation of green from gray was 

 not as easy or complete as desirable. From subsequent generations a 

 pure stock of green was made. A green female by wild male gave 138 

 wild-type females and 127 males which were greenish. This green 

 color varies somewhat in depth, so that some of these FI males could 

 not have been separated with certainty from a mixed culture of green 

 and gray males. 



The results of these two experiments show that green is a sex-linked 

 melanistic character like sable, but the somatic difference produced is 

 much less than in the case of sable, so that the new mutation, although 

 genetically definite, is of little practical value. We have found several 

 eye-colors which differed from the red color of the wild fly by very 

 small differences. With some of these we have worked successfully by 

 using another eye-color as a developer. For example, the double reces- 

 sive vermilion "clear" is far more easily distinguished from vermilion 

 than is clear from red. But it is no small task to make up the stocks 



