84 



T. H. MORGAN 



TABLE 2 



The offspring of red-eyed daughters of pair L, which when mated to white-eyed males, 



gave 1:1 sex-ratios 



BED 9 9 



WHITE 9 9 



RED d'c?' 



WHITE cfcf 



Dup. 

 Dup. 



Dup. 

 Dup. 



Dup. 

 Dup. 

 Dup. 



LI.. 



L2.. 



L3.. 



L3.. 



L6.. 



L6.. 



LIO. 



L12. 



L15. 



L16 



L17. 



L17. 



L19. 



L19. 



L22. 



L25. 



L25. 



L28. 



L28 



L31. 



L31. 



L33. 



Totals . 



32 

 36 

 13 

 24 

 52 

 30 



2 

 19 

 75 

 26 

 38 

 11 

 63 

 24 

 24 

 68 

 40 

 32 



5 

 30 

 24 

 22 



690 



573 



613 



541 



* The cases marked 'Dup.' refer to a second lot of offspring produced by the female of a given number. 



it is assumed that breaking and crossing-over is infrequent in pro- 

 portion as these loci are close together. 



These relations can be represented by means of the following 

 analysis and by figure A. Let X stand for the sex differentia- 

 tor, 1 for the recessive lethal factor and L for its dominant allelo- 

 morph, w for the factor which determines white eyes and V^ for 

 its normal allelomorph. The analysis for the cross of the female 

 heterozygous for lethal and the white-eyed male is as follows: 



Pi Lethal-bearing red-eyed 9 X 1 W — X L W 



Normal white-eyed c?' X L w — 



Fi females Fi males 



X 1 WXLw red 9 (A) XI W red d" (dies) 



X L W X L w red 9 (B) X L W red d' (lives) 



