PAPER SHELL WALNUTS 37 



American black walnut ; it is as easily grown, and 

 perhaps even less particular as to soil and cli- 

 mate. The trees are very productive, especially 

 as they grow older. The branches droop under 

 the weight of the nuts. Where other walnut 

 trees bear nuts singly or in clusters of twos or 

 threes, the Japanese walnut tree bears long 

 strings of nuts, sometimes thirty or more in a 

 single cluster. The nuts are thickly set about 

 the axik, the cluster being from six to twelve 

 inches in length. 



The meats of the cordiformis drop out com- 

 plete when the thin shells are cracked. 



Hybridizing Native Walnuts 



The cross between the Persian and Japanese 

 walnuts, like that between the Persian and the 

 California black walnut, did not result in pro- 

 ducing a tree that had exceptional value as a 

 nut producer. This cross, like the other, brings 

 together strains that are too widely separated; 

 and while there is a great accentuation of the 

 tendency to growth, so that trees of tremendous 

 size are produced, there is relative sterility, 

 so that a tree sometimes bears only a few indi- 

 vidual nuts in a season. 



But the results were very strikingly different 

 as regards the matter of bearing when the Cali- 



