Some Experiments by Luther Burbank 



'have a very brief history compared with the 

 wild species, and, moreover, they are constantly 

 being placed in a new environment by man, 

 being influenced by new soils, new climates, 

 new fertilizers and the like/ ''Breeding to a 

 fixed line will bring fixed results. Man's des- 

 ultory breeding is brief, the struggle for exis- 

 tence is mostly absent, and new ideals and 

 new uses are required instead of ability to 

 endure under natural conditions. Man's efforts 

 at selective breeding are fluctuating, with frequent 

 saltations." 



Dr. De Vries notes that in the common sugar 

 beet, which is a biennial species, there are from 

 one to ten per cent of plants which bear seed the 

 first year. None of these is ever chosen for seed, 

 and yet the long-continued process of natural selec- 

 tion has never succeeded in rooting them out. As 

 to this Mr. Burbank observes: "This long-fixed 

 tendency to insure continued existence in the past 

 is not yet bred out. Analogous to this is the ten- 

 dency in flocks to produce black sheep, and the 



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