BULLETIN 231] 



WALNUT CULTURE IN CALIFORNIA. 



207 



of development and these second-generation Paradox seedlings may 

 therefore be dropped out of consideration. 



The next question which suggests itself is the possible utilization 



FIG. 28. Four-year-old Placentia tree on English root. 



of first-generation Paradox trees; seedlings, in other words, which 

 come directly from black walnuts which have been cross-fertilized with 

 pollen of the English walnut. Such trees, as we have shown elsewhere, 



