A THIRP SEX-LINKED LETHAL 



321 



The small numbers in the first experiment gave a distance 

 between lethal III and vermilion of 5.4; the second gave 7. The 

 data of both experiments gave 6.8. 



In a third case vermilion females (lethal-bearing) were crossed 

 singly to vermilion miniature males and gave: 



These results gave a distance of 9 units between the lethal 

 involved and miniature and the lethal may lie either to the right 

 or to the left of miniature. If to the left, the locus corresponds to 

 lethal III and may be so taken. 



A HIGH SEX-RATIO 



A vermilion female (IXX-^) second generation from r2 was bred 

 to a vermilion male. Two of her vermilion daughters were bred 

 (in the same culture)^ to two white vermilion brothers and gave a 

 ratio of: 



Vermilion 9 

 71 



Vermilion cf 

 3 



A remarkable high sex ratio is here met with. Many of the 

 vermilion daughters were bred separately. A partial report of ^he 

 results, namely, most of the cases in which the females were bred 

 to eosin miniature males, is included in table 5. 



Certain other daughters (of the 71) were bred to their (three) 

 vermilion brothers and gave the results shown in table 6. 



Still other daughters (of the 71) bred to eosin miniature males 

 gave the results seen in table 7 ; where, in addition to the regular 

 classes of females, there are some irregular classes that cannot be 

 explained. These exceptional individuals appeared only in the 



' It is possible that the offspring came from only one of these females. 



