SEX-LINKED LETHALS IN DROSOPHILA 



105 



From the lot jj (table 16) nine red-eyed females were bred to 

 eosin vermilion males. The results show (in table 17) that 

 the second lethal was present in the red-eyed females. In the 

 lower part of the same table there are four cases recorded in which 

 only vermilion and eosin vermilion offspring were produced. 

 The sex-ratio 2:1 recurs. The results are undoubtedly due to 

 four vermilion females (1, 5, 10, 14) from jj of table 10 having 

 been taken instead of red females as intended. 



From lot c of table 16 also seven red-eyed females were bred 

 to eosin vermilion mTales. The results are given in table 18, which 

 is similar to the preceding tables. 



The sum of all the female classes that belong to the 2:1 divi- 

 sion in tables 2 to 6 b and the sum of the corresponding males, 

 is as follows : 



females 

 red long white min. red min. white long 



1964 1835 916 852 



males 

 3 1690 247 290 



The hnkage shown in these results will be discussed later. 



TABLE 17 

 (From No jj of table 16) 



