LUTHER BURBANK 
fornia today, as it is of the Gulf States. In both 
of these regions experimenters should take up the 
work. It is at least possible that new and strange 
citrus fruits may thus be brought into being. 
As a single hint suggestive of possibilities, let 
me recall that the very earliest plum in existence 
today is probably the one that I developed by 
successive hybridizations which ultimately intro- 
duced and blended the strains of six of the latest 
plums. 
Possibly, then, the problem of developing an 
orange resistant to cold—one that may be grown 
not merely along the Gulf but along the Great 
Lakes as well—may be solved in similar fashion. 
It seems paradoxical to suggest that the blending 
of oranges from half a dozen tropical and sub- 
tropical climates—India, Arabia, Northern Africa, 
Brazil, Florida, Southern California—might pro- 
duce a fruit adapied to the climate of, let us say, 
Missouri or Ohio; yet the case of my early plum, 
descended from late ancestors, suggests that this 
idea is not altogether chimerical. This work will 
be greatly simplified by the fact that we now have 
an orange, before mentioned, which, without 
special selection for this purpose, is now hardy as 
far north as Philadelphia. 
OTHER Sup-TropicaL FRvuITS 
And a similar suggestion may be made regard- 
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