C. Pellbw and F. M. Durham 175 



Certain Fn plants from the above crosses were bred I'rom and gave 

 the following results: 



Lemons selfed. 



37 31x18 „, ... 



.j- . ex -^"s — gave 1 lemon, like parent. 



54 37x18 _, ^ . , ... 



zr-T ex — — — gave 20 lemon : 5 isabellina. 



~ ex — r-r — gave 26 lemon, dark and pale shades. 

 14 12 



Yelloivs heterozygous for lemon and isabellina selfed. 



53 37 X 18 ,, ,, ,, , ^ . , „. 



:j~; ex — r-^r — gave 7 yellow : 9 lemon : 5 isabellina. 



52 37 X 18 



14 '^^ 12" " 9 " ^ ■' 6 ■■ 



Totals 16 14 11 



51 37 X 18 



z-j- ex —-^ — gave 10 pale yellow and lemon (not recorded separately) 



and 3 isabellina. 



The following crosses were made among the Fi and F.^ j)lants. 

 56x50 



14 



Yellow F^ (heterozygous for lemon and isabellina) x isabellina F^. 

 13 yellow : 12 lemon : 17 isabellina. 



51 x 55 , 



— —I — Yellow F2 (heterozygous for lemon and isabellina) x lemon Fa. 



25 yellow: 16 lemon. 



59 X 50 



— ~ — Yellow F.> (heterozygous for lemon) x isabellina F.^.- 



8 yellow : 5 lemon. 



We are not at present in a position to interpret these numbers. It 

 seems probable that two pairs of factors are involved, but our numbers 



