542 



MARY B. STAEK 



males. It was expected that only a few of the red eyed males 

 would appear in the second generation if red and lethal were 

 closely linked. Results (table 11) show, however, that a great 

 number of red males appear. Such a result indicates that a new 

 lethal had appeared which was located some distance from the 

 factor for white, thus giving a chance for a greater amount of 

 crossing over. 



In table 11 it will be noted that the percentage of crossovers is 

 46. This would place the lethal somewhere beyond the factor 

 for sable and not far from the factor for bar eyes upon the sex 

 chromosome. 



