86 



GERT RONNIER 



TABLE 2. 



Offspring of eosiii exceptional daughters from high non-disjunction 



cultures when crossed to males from other sources. 



TABLE 3. 



Offspring of eosin exceptional daughters from table 1 when mated by 



males which among others carried the gene eosin. 



Percentage of exceptions 17,42 i: 3,:io. \ 



Finally exceptional daughters from tables 2 and 3 were crossed to 

 still other kinds of males and this was carried on for two generations. 

 As table 4 shows the output was li073 flies with the percentage of ex- 

 ceptions 21,44 4:1,25. 



