FIXING GOOD TRAITS 31 



the mixed ones of any given generation under 

 these circumstances becomes a matter of enor- 

 mous 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 ac- 

 complished 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 

 disseminate the new variety. And in most cases 

 we are justified in feeling that this would repre- 

 sent an undue expenditure of time and energy 

 for a comparatively insignificant result. 



For, as the case stands, even though the new 

 form will not breed .true from seed, it may be 

 propagated indefinitely from roots or from the 

 grafting of cions; so that in practice the failure 

 to breed true from seed has little significance. 



Probably it is the fact of the relative unim- 

 portance that our cultivated plants should breed 

 true from seed that chiefly explains the failure 

 of plant breeders in the past to fix the type of 

 the best known fruits and vegetables and flowers 



The same reasoning obviously applies to the 

 newly developed varieties. While so much work 

 remains to be done in the way of developing 

 new types of fruit and flower, the most practiced 



