LUTHER BURBANK 



and that the individuals in question will all bear 

 large fruit. 



So we may expect (on this assumption), having 

 grafted our selected seedlings, that each of them 

 will show, two or three years hence, fruit of large 

 size. 



But of course the other qualities of this fruit 

 will not be all that we could desire, so it will be 

 necessary to continue the experiment. 



Suppose we do this by cross-pollenizing differ- 

 ent members of the same group. We shall thus 

 mate Bb with Bb. And the result of this mating, 

 as we know, will be to produce, in each group of 

 four, one BB individual, two Bb individuals, and 

 one bb individual. Being interpreted in terms of 

 our actual row of seedlings, as they stand in our 

 orchard in this, the fourth or fifth year of our ex- 

 periment, this means that in every lot of four 

 thousand seedlings one thousand are pure domi- 

 nants as regards large fruit, two thousand are 

 mixed dominants, and one thousand are pure re- 

 cessives. 



But now comes a very tangible and very prac- 

 tical complication. As regards their external 

 traits, and as regards the fruit that they will indi- 

 vidually bear, the one thousand pure dominants 

 (BB) and the two thousand mixed dominants (Bb) 

 are identical. There is nothing in their exterior 



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