THE LINKAGE OF TWO FACTORS IN DROSOPHILA 

 THAT ARE NOT SEX-LINKED. 



T. H. MORGAN AND CLARA J. LYNCH. 



In addition to the eight sex-linked factors described for Droso- 

 phila, a number of other factors have been found that are not 

 sex-linked. They are now being studied in order to discover 

 which, if any, of them are linked to each other. Two that have 

 been found to be linked are here described. These are the yellow 



FIG. A. 



factor in the absence of which the flies are black, and a factor 

 (in the complex of factors that produces the normal wing) in the 

 absence of which the fly is wingless. 



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