LUTHER BURBANK 



trees have been cut off, there will spring up what 

 at first appears to be a growth of oaks alone. But 

 in fifteen or twenty years the growth of Douglas 

 Spruce will entirely overshadow the oaks, ulti- 

 mately kiling them off altogether, and presenting 

 yet another illustration of the practical operation 

 of natural selection. 



But there is very great variation among the 

 different species of conifers as to rapidity of 

 growth. So there is fine opportunity for the experi- 

 menter to select the more rapid-growing trees, and 

 thus to develop a race of timber trees of excep- 

 tional value. 



The experiment is not difficult because the 

 Douglas Spruce bears seed while quite young, par- 

 ticularly when the trees stand by themselves. The 

 seed remains in the cones for some time, to mature, 

 so that it may be collected at any season of the 

 year. The seeds germinate readily, the seedlings 

 may be easily transplanted, and in general this is 

 one of the easiest conifers with which to work. 

 The hardiness of the tree and its adaptation to all 

 soils and climates are further merits that com- 

 mend it to the attention of the plant developer, 

 whether he have in mind a tree for ornament or 

 for reforestration. 



The experimenter should know, however, that 

 the seed of the spruce, unlike that of the redwood 



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