56 LUTHER BURBANK 



sufficient size, I grafted them on these Euro- 

 pean and American trees, in this way being able 

 to stimulate development, and to observe the 

 progress of cions from several hundred seedlings 

 on the same tree. 



This, of course, is precisely the method used 

 with my plums and other orchard fruits. The 

 advantages already detailed in connection with 

 the orchard fruits were, of course, found to 

 apply equally to the chestnut. The ingrafted 

 cions were led to fruit much earlier than they 

 would have done on their own roots; there was 

 saving of space; and it was easy to hybridize 

 the many cions that were thus collected on a 

 single tree. 



Of course, I was carrying forward numerous 

 experiments with the chestnut all at the same 

 time — crossing each species with every other spe- 

 cies, so that in a single season there would be a 

 large number of hybrid forms of different par- 

 entage. So when two of the hybrids were inter- 

 bred the strains of four different species or vari- 

 eties were blended. Thus a hybrid of the second 

 generation might combine the ancestral strains 

 of the Japanese and European and American 

 chestnuts and of the little chinquapin. 



Thus opportunity was made for wide selec- 

 tion among hybrids that combined these various 



