2 TREE ANCESTORS 



since I have chosen forms whose history was better known, but 

 not worn threadbare, and omitted others where the evidence was 

 incomplete or conflicting, as in the case of the pines, spruce, and 

 their allies. 



The reader need know no geology or botany as all unnecessary 

 technicalities have been avoided. One cannot, however, discuss 

 history without some sort of a chronology, and I have therefore 

 given a simplified geological time table in Chapter II which will be 

 sufficient after it has been understood to render clear such refer- 

 ences as appear in the following pages. 



The main theme then will be the geological or distribution in 

 time, and the geographical or distribution in space, of the trees. 

 Although I will not refrain from mentioning the usefulness of the 

 trees to us humans, it should be remembered that a tree is no longer 

 a tree when it has become timber, and it is only in deference to a 

 practical people and to a forestry which regards our woodlands as 

 so many potential board feet that utihty may be considered as a 

 possible avenue to a more general appreciation of the wonders of 

 their present state and the grandeurs of their past history. 



