444 



T. H. MORGAN AND C. B. BRIDGES 



Pi 



pink? 



XWVp — XWVp 



One of the preceding experiments (page 439) furnishes data 

 for the amount of association of the factors eosin and vermilion. 

 In both the former cross and in this cross the gametic ratio is 

 shown directly both in the male and female classes. The classes 

 of the preceding experiment, added to those here give as totals: 



w«v 



1717 



wv 



3424 



w'^v 

 3469 



Wv 

 1729 



The sum of the classes showing the original combinations is 

 6893 and the crossover combinations 3446, which gives a per- 

 centage of crossing-over (or chromosomal distance) of 33.3. 



Pink heterozygous for white and vermilion 



The pink daughters from the cross pink female by white ver- 

 milion pink male were identical with stock pinks, although hetero- 

 zygous for white and vermilion : 



