LUTHER BURBANK 



Perhaps the comparison may be thought 

 somiewhat whimsical; but I am led to make it 

 because I thought it might serve to suggest the 

 complexities and difficulties that attend a plant- 

 breeding experiment that involves the blending of 

 numerous desired characters. 



And the lesson that I wish pre-eminently to 

 inculcate is this: You must make many experi- 

 ments at plant-breeding before you can hope to 

 secure the combination — ^the sequence of qualities 

 — that you desire. 



The Logic of Qdanttty Production 



Now note the application: Each individual 

 seedling of a hybrid strain represents a unique 

 combination of ancestral traits, and constitutes in 

 itself a new and unique experiment — equivalent 

 to an independent deal of the cards. So the prob- 

 ability of securing what we seek will be somewhat 

 proportionate to the number of seedlings. 



This is particularly true in the case of such 

 variable plants as the fruit trees of our orchards. 

 The case is far simpler when we are dealing with 

 plants that vary little in their qualities, or where 

 we are breeding with only a single pair or two 

 pairs of unit qualities in mind — say "hardness" 

 of kernel and immunity to rust, as in Professor 

 Biffin's experiments with wheat; or good flavor 

 and whiteness as in my white blackberry. 



[112] 



