INTRODUCTION 



A GOOD many popular books on trees have been published 

 in the United States in recent years. The continually 

 increasing demand for books of this character indicates the 

 growing public interest not only in the trees that we pass 

 in our daily walks, but also in the forest considered as a 

 community of trees, because of its aesthetic and protective 

 value and its usefulness as a source of important economic 

 products. 



As a nation, we are thinking more about trees and woods 

 than we were wont to do in the years gone by. We are 

 growing to love the trees and forests as we turn more and 

 more to outdoor life for recreation and sport. In our 

 ramblings along shady streets, through grassy parks, over 

 wooded valleys, and in mountain wildernesses we find 

 that much more than formerly we are asking ourselves what 

 are these trees what are the leaf, flower, twig, wood and habit 

 characteristics which distinguish them from other trees; 

 how large do they grow; under what conditions of soil and 

 climate do they thrive best; what are their enemies and how 

 can they be overcome ; what is their value for wood and other 

 useful products ; what is their protective value ; are they use- 

 ful for planting along streets and in parks and in regenerat- 

 ing forests; how can the trees of our streets and lawns be 

 preserved and repaired as they begin to fail from old age 



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