LUTHER BURBANK 
united, racial traits that are reminiscent of the 
old days when the northern hemisphere enjoyed a 
tropical climate may be revived, and a tendency 
to repeat a gigantic growth that characterizes 
ancestors vastly remote will be revealed. 
Such, I take it, is the explanation of the strange 
and otherwise inexplicable phenomena of gigant- 
ism manifested by my hybrid walnuts. And such 
is our warrant for believing that all other species 
of native trees have possibilities of development 
that are unrevealed in the exterior appearance of 
their present-day representative, and that can be 
revealed, so far as we know, only by hybridization. 
—New hybrids must be pro- 
duced by the union of varied 
species of pines, oaks and 
elms, and other shade and 
ornamental trees, to give di- 
versity to the landscape and 
to supply different types 
of wood for use of car- 
penters and cabinet-makers. 
