LUTHER BURBANK 
of this variety throughout a term of years may be 
higher than that of others that in any given season 
may surpass it. 
There is obvious opportunity to hybridize this 
variety with the other varieties of the Persian wal- 
nut that blossom earlier, but produce a better crop 
of nuts. Such crossing would doubtless supply 
material from which races may be developed that 
will retain the late blossoming habit of the Fran- 
quette, combined with the nut producing qualities 
of the other parent. 
We have seen that a tendency to fruit late in 
the season is usually correlative to a tendency to 
early ripening of fruit so that late bloomers are 
adapted to growth relatively far to the north. A 
late blooming strain of the Franquette walnut 
might furnish material for the development of a 
variety of walnuts that will be hardy enough to 
grow in higher altitudes than those to which the 
English walnut is now limited. But for the pro- 
duction of real hardy races it is probable that 
hybridizing with the black walnut—the same cross 
that produced the Paradox—must be looked to, to 
supply the foundation for a series of experiments 
in selective breeding. 
The pioneer work, indeed, has been done in 
the production of the Paradox walnut itself. 
It may reasonably be supposed that further 
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