BERRIES AND GARDEN FRUITS 



tion as one of its most pronounced attributes 

 although the specimen with which your experi- 

 ment began may have shown only the faintest 

 trace of it. 



You may thus develop a new flavor, for ex- 

 ample. Or you may double or quadruple the size 

 of the fruit. The secret of success is to select 

 rigidly plants that show variation, and breed from 

 them. 



One very important thing to understand, how- 

 ever, is that your selection should be based not 

 on an individual berry, but on the average product 

 of a vine. A single fruit may chance to grow 

 under exceptional circumstances alone on a vine, 

 or particularly favored by light or nourishment 

 and so may attain what might be called abnormal 

 proportions. Such a fruit is not more likely to 

 produce large progeny than the smallest, meanest 

 fruit on the plant. It is heredity that counts, not 

 the peculiarities of an individual plant. 



But if you find a plant whose average product 

 is larger than the ordinary, you may with con- 

 fidence save the berries of that plant for seed, and 

 you will almost surely get some seedlings that 

 will bear berries even larger than those of the 

 parent plant. Even if there is not much improve- 

 ment in the first generation, there is likely to be a 

 cumulative effect with successive generations, and 

 a time will come when striking results will be 

 apparent. 



Mr. Burbank speaks of this cumulative tendency 

 as "the momentum of variation." It has often 



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