LUTHER BURBANK 



Even where only two unit characters are 

 involved, the progeny of the second generation, 

 as we have just seen, may break up into numerous 

 races, some fixed and others variable. And, as 

 we have previously pointed out, the complications 

 thus introduced increase at a startling ratio when 

 more characters are under consideration. 



Moreover, the matter is rendered increasingly 

 difficult for the plant experimenter by the fact that 

 he must often wait, particularly in the case of 

 orchard fruits, for a term of years before he can 

 know the result of any single breeding experiment. 

 To sort out the pure types from the mixed ones of 

 any given generation under these circumstances 

 becomes a matter of enormous complexity. 



It could be done, by inbreeding representatives 

 of the new type and carefully selecting the progeny 

 for a series of generations. 



But in the end, all that would have been accom- 

 plished, in the case say of a Shasta daisy or of a 

 stoneless plum or a sugar prune, would be the 

 production of seed that could be used to dissemi- 

 nate the new variety. And in most cases we are 

 justified in feeling that this would represent an 

 undue expenditure of time and energy for a com- 

 paratively insignificant result. 



For, as the case stands, even though the new 

 form will not breed true from seed, it may be 



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