2O4 Double Stocks [CH. xi 



symmetrical or probable scheme of character-distribution by 

 which such a phenomenon can be represented. 



The various difficulties of the case culminate in the fact 

 which seems well established, that though the double- 

 throwers generally give 7 singles : 9 doubles with certain 

 departures from this ratio which are probably not fortuitous 

 yet F^ raised from single x double-thrower, and from the 

 reciprocal cross, always on self-fertilisation gives 3 singles : 

 i double*. 



* The relation of white to cream-colour in the strain known as "Sulphur" 

 is approximately the same as that of single to double described above. 

 " Sulphurs " are single whites throwing singles all white, and doubles which 

 are usually creams with whites as exceptions. The pollen-grains of "Sulphur" 

 all bear cream, while of the ovules some are creams and some whites. 



