LETHAL FACTOKS IN DROSOPHILA 



549 



TABLE 12(b) 

 Red eyed 9 heterozygous for sable and lethal X sable cf 



The total number of males = 1641; Crossovers = 387. 

 The crossover percentage = 387 -r- 1641 or 23.5. 

 Therefore, the distance of lethal from sable is 23.5. 



of one of the lethal factors from one chromosome in the other, 

 thus freeing one chromosome from its lethal factor. 



TABLE 13 



13, 2, 1, 4 



