LUTHER BURBANK 



He does not attempt to make squash vines into 

 oak trees, or blackberry briers into tomatoes. 



He recombines those newer, and hence less im- 

 portant, structures and qualities of which the fact 

 of their Mendelizing is adequate proof of their 

 newness and relative unimportance. If he would 

 get beyond this and create really new forms, add- 

 ing something to the plant that no ancestor of the 

 plant ever had, he could hope to do this only if a 

 term of life were granted him that would be meas- 

 ured not in mere years but in millenniums. For 

 evolution is a slow process, and the history of the 

 development of natural species is measured in 

 geological eras. 



SELECTION AND MENDELISM 



Perhaps it may be worth while to illustrate this 

 matter a little more in detail, that we may make 

 clear precisely what manner of thing the plant 

 developer is doing when he produces a new race 

 by selection. 



We have stated over and over that the process 

 of hybridizing and the process of selection are 

 complimentary. One supplements the other. In 

 hybridizing we make possible new combinations of 

 the hereditary factors, and in selecting through 

 successive generations we isolate certain definite 

 combinations, and thus produce what we call new 

 varieties. Now it is frequently stated by the ex- 



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