NEW DATA. 



dence that yellow and club give 18 per cent of crossing-over, club and 

 vermilion 20 per cent, and yellow and vermilion 35 per cent. The 

 double cross-overs on this view are yellow club (3) and vermilion (3). 

 The females furnish additional data for the linkage of club and ver- 

 milion. The value calculated from the female classes alone is 20 units, 

 which is the same value as that given by the males. 



TABLE 51. PI club 9 9 X vermilion cf cf. PI wild-type 9 X PI club cf . 



TABLE 52. PI club vermilion 9 9 X yellow cf cf. 



X PI club vermilion cf cf. 



wild-type 9 9 



