ON DAISIES 



tion, and the principles according to which the 

 experimenter works in effecting such fixation have 

 been pointed out again and again. 



Making application of the knowledge thus 

 gained to the case of the Shasta daisy, we need 

 have no hesitancy in asserting that it would be 

 possible to fix races of this plant so that they 

 would reproduce their type with approximately 

 the certainty from the seed as do, for example, 

 the original parent forms from which they spring. 

 But this task is as unnecessary as would be the 

 task of fixing roses, carnations, or chrysan- 

 themums. 



If inquiry is made as to the length of time 

 required to effect such fixation of type, the answer 

 can be given with a fair degree of certainty. Work- 

 ing along usual lines, by selecting the best speci- 

 mens in a large company and in the successive 

 year the best specimens among their progeny — 

 extending, in other words, the method of selection 

 through which the new races were originated — it 

 would probably require from six to ten genera- 

 tions of selection to make sure of securing a speci- 

 men from the germ plasm of which disturbing 

 hereditary factors had been eliminated by selec- 

 tion so that the factors that remain are those that 

 produce the qualities that we desire to retain. 



But if it were feasible to devote the space and 



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