LUTHER BURBANK 



culties encountered in extracting the meat of the 

 nut are too great. Contrariwise, a nut that has a 

 shell so thin that it can easily be crushed in the 

 fingers is sure to make its way and to be found 

 more and more generally on the dinner-table. 



The terms "paper-shell" and "soft-shell" as 

 applied to the walnut are interchangeable. There 

 are now several varieties of walnuts on the mar- 

 ket that are generally classified under one head 

 or the other. Their name merely refers to the ease 

 with which the nut can be cracked. As to this there 

 is great variation among ordinary walnuts, and 

 the soft-shell varieties also show a good deal of 

 diversity. But the best varieties are so friable that 

 they can readily be crushed in the fingers. 



In point of fact, the walnut is so variable that 

 it is possible for the plant developer to consult 

 his own wishes in the matter of modifying its 

 shell. I have developed a variety in which the 

 shell became so soft that it could readily be pene- 

 trated by the bills of birds; in fact a nut that had 

 a mere rim of shell, being thus comparable to the 

 stoneless plum. There would be no difficulty in 

 maintaining this variety of shell-less walnuts, but 

 its thinness of shell was a disadvantage, and I 

 found it desirable to breed the variety back to a 

 somewhat thicker shell covering, by striking a 

 compromise between the old hard-shell varieties 



[36] 



