THE CREATION OF NEW TREES 



apparently been impossible. But this much 

 may be done even in these remote cases: 



"Two given species will not readily yield 

 to union. Make a cross between them, take 

 the seeds of the progeny and plant them. 

 Cross two other diverse species in the same 

 way and plant the seeds of their progeny. 

 Then to the progeny of the first union unite 

 the progeny of the second, and from this later 

 union you may sometimes get marvelously 

 satisfactory results. The outcome of either 

 main cross would be unsatisfactory, perhaps 

 unimportant; the union of their progeny may 

 obviate the difficulty. The possibilities of 

 such crossing and its subsequent selection are 

 inconceivably great. 



"It is my opinion that one of the most 

 important, in some ways the most important 

 of all the many fields open now to the plant- 

 breeder, is this one of the production of new 

 and the improving of old trees. I believe it 

 to be of immense significance commercially." 



Closely allied to this production of a tree is 

 the improvement of the product of the tree, 

 its nuts. Deciding that it would be well to 

 have an English walnut with a thinner shell, 



65 



