320 



T. H. MORGAN 



Other vermilion females were out-crossed to eosin miniatm'e 

 males. From the cultures that showed sex-ratios females were 

 back-crossed singly to eosin miniature males. The back-cross 

 cultures that gave sex-ratios are seen in table 4. 



The results of the experiment confirm the location of the genes 

 in diagram 1, as the following chromosomal distances show: 



Eosin lethal III 20.2 



Eosin vermilion 27.0 



Eosin miniature 29 . 



Lethal III vermilion 7.0 



Lethal III miniature 9.3 



Vermilion miniature 2.3 • 



TABLE i 



Females 



Males 



