108 LUTHER BURBANK 



must heed the lessons it gives in common with 

 the hybrid walnuts as to the possibility that a 

 tree may show almost abnormal capacity for 

 rapid growth and at the the same time may pro- 

 duce lumber of the hardest texture. 



Hitherto it has generally been supposed that 

 a tree of rapid growth would as a matter of 

 course produce soft timber. The hybrid wal- 

 nuts and the various eucalyptus trees serve to 

 dispel that fallacy. 



NATIVE MATERIALS 



The one fault of the eucalyptus, its inability 

 to stand extreme cold, is likely to be shared by 

 other trees that are imported from the sub- 

 tropical regions of our own hemisphere. 



Although, as just suggested, it may be possible 

 to overcome this fault through selective breed- 

 ing, a long series of experiments will doubtless 

 be necessary before this can be accomplished. 

 In the meantime we shall be obliged to place 

 chief dependence, in all probability, upon our 

 native stock of trees, hybridized perhaps with 

 allied species of Europe and northern Asia. 



But, even so, there is no dearth of material. 

 America is richly stocked with forest trees. 

 Moreover these represent, so the geological 

 botanists assure us, a flora of very ancient origin 



