316 



T. H. MORGAN 



L 



V 



X 



X X 



w 



V A 



Diagram 1 



chance. This experiment has been repeated, therefore, in small 

 mass cultures and has given, in Fo, the totals shown in table 1. 



Males 



The females conform to expectation. The males show many 

 irregularities that will be discussed in another connection. Classi- 

 fied as in the original experiment, the males give: 



Totals Per cent 



Non-cross-overs 662 63.8 



Single cross-overs between white and vermilion. . 335 31.8 

 Single cross-overs between verm, and minia- 

 ture 49 4.7 



Double cross-overs 7 0.7 



The totals of these new results for the males approach very 

 closely to expectation both for the amount of double crossing-over 

 and also for the distances apart of the genes, despite other inequali- 

 ties that appear in the results. 



In the experiment as actually carried out a non-sex-linked gene, 

 namely, the gene for pink eyes, is involved. The additional 

 classes that are thus introduced are ignored in the preceding calcu- 

 lations in which pink and not-pink classes are combined. If we 

 take pink into consideration the following relations will be found. 

 The gene for pink lies in another chromosome, and since the Fi 



