THE ROYAL WALXUT 85 



been able to make their traits manifest, but which 

 have always transmitted these potentialities as 

 submerged and subordinated tendencies. The 

 admixture of the divergent racial strains one 

 from Europe, the other from California, or in the 

 case of the Royal, from origins separated by the 

 breadth of a continent sufficed to bring together 

 factors of growth that for all these generations 

 had been separated, and the atavistic phenom- 

 enon of a giant walnut came into being. 



Thus interpreted, the case of the big walnut 

 is not dissimilar to the case of our white black- 

 berries or to that of the fragrant calla. 



In each of these instances, as in that of num- 

 berless others that we shall have occasion to ex- 

 amine, a mixture of racial strains brings about a 

 reversion to the structure or quality of a remote 

 ancestor. 



In the case of the walnuts we have had occasion 

 to go back a few thousand generations farther 

 than in the other cases, but there is ample warrant 

 for believing that nature sets no limit on the 

 length of time throughout which a submerged 

 character may be transmitted, with full possi- 

 bilities of ultimate restoration. 



We shall have occasion to examine further evi- 

 dence of the truth of this proposition, drawn 

 from a quite different field, in a later chapter. 



