92 T. H. MORGAN AND ELETH CATTELL 



LRN 9 = 588 



LRB 9 •= 189 



LWN 9 = 204 



LWN d" = 224 



LWB 9 = 98 



LWB d" = 95 



SRN 9 = 225 



SRB 9 = 72 



' SWN 9 = 410 



SWN cf = 418 



SWB 9 = 145 



SWB d' = 145 



SRY cf = 161 



SRBr cT = 47 



LRY d = 419 



LRBr d = 102 



LRB cT = 1 



SWY c^ = 5 



(SWBr 9=1) 



LWBr d = 1 



The expectation is as follows: 

 Pi 



SVVByX - SWByX 

 IRYbX - Yb 



SWBYX - SWByX - LRYbX - LRybX , 



Gametes LWBYX - LWByX - SRYbX - SRybX J ^^^ 



of Fi 



SWBYX - SWByX - Yb - yb Sperm 



' There are seven cases of crossing-over in color. In addition 

 there is one record of SWBr 9 which must be either an error, or 

 a mutation, since both the female-producing sperm carry the 

 factor for black, hence no brown females are possible. Omit- 

 ting this single case there are seven cases of crossing-over in 1611 

 males. Of these one is one way (RB), and six in the opposite 



