142 MENDELISM en 



picotee cannot throw the two deeper shades of red 

 or purple. But it may be heterozygous for the 

 purpling factor, when it will throw the dilute red 

 (Tinged white), or it may be heterozygous for either 

 or both of the two colour factors (cf. p. 41), in 

 which case it will throw whites. Of the picotees 

 which come in such a family, therefore, some will 

 give picotees, tinged whites, and whites, others will 

 give picotees and tinged whites only, others will give 

 picotees and whites only, while others, .again, and 

 these the least numerous, will give nothing but 

 picotees. The new variety is already fixed in a 

 certain definite proportion of the plants ; in this 

 particular instance in i out of every 27. All that 

 remains to be done is to pick out these plants. 

 Since all the picotees look alike, whatever their 

 breeding capacity, the only way to do this is to save 

 the seed from a number of such plants individually, 

 and to raise a further generation. Some of them 

 will be found to breed true. The variety is then 

 established, and may at once be put on the market 

 with full confidence that it will hereafter throw none 

 of the other forms. The all-important thing is to 

 save and sow the seed of separate individuals 

 separately. However alike they look, the seed from 

 different individuals must on no account be mixed. 

 Provided that due care is taken in this respect no 

 long and tedious process of selection is required for 

 the fixation of any given variety. Every possible 

 variety arising from a cross appears in the F 2 

 generation if only a sufficient number is raised, and 

 of all these different varieties a certain ^proportion of 

 each is already fixed. Heredity is a question of 



