ON PAPER-SHELL WALNUTS 
others that grow only six or eight inches. One 
grew five hundred times as fast as another, the 
nuts from which they grew having been picked 
from the same tree, and planted the same day side 
by side. 
To make sure of securing trees having the traits 
of the original Royal, it is necessary to grow the 
trees from grafts either of the first generation 
hybrid or a selected second generation hybrid 
showing rapid growth. The number of the latter, 
however, is sufficient to ensure a reasonable pro- 
portion of good trees from any lot of seed; and 
the Royal has been in general demand as a tree to 
furnish stocks on which the Persian walnut may 
be grafted. 
It is found that on most soils a Persian walnut 
grafted on roots of the Royal hybrid will produce 
several times as large a crop as if on its own roots. 
Moreover the trees under these conditions are 
relatively free from the blight. 
The nuts of the Royal hybrid are similar to 
those of the parents, except that they are larger in 
size. The very thick shell is objectionable, as 
already noted. Doubtless the shell can be made 
thinner by selective breeding, but no comprehen- 
sive efforts in this direction have as yet been car- 
ried out. The black walnut, in spite of the really 
fine quality of its nut, has never become an impor- 
[49] 
