ON TIMBER TREES 



recollection of these vicissitudes, can adapt itself 

 to the inhospitable conditions of our modern cli- 

 mate are but dwarfed representatives of ancient 

 races of giants. To preserve life at all it was 

 necessary for them to conserve their energies; and 

 gigantic growth is feasible only for plants that can 

 send their roots into rich, well watered soils and 

 can likewise draw sustenance perennially from 

 the atmosphere, unhampered by long periods of 

 dormancy when life itself is threatened. 



But these dwarfed races carry in their germ 

 plasm, submerged but not eliminated, factors for 

 giant growth; factors for such development as 

 would adapt them to life in the tropics; factors 

 also for such development as would adapt them 

 for life in the arctics. 



Their hereditary factors, in a word, are as 

 varied as have been their past environments. So, 

 as I said, what each tree is exteriorly gives us but 

 faint suggestion of what it might be were its un- 

 realized hereditary possibilities to be made 

 actualities. 



So far as we know at present, the only way in 

 which these unrealized possibilities may in any 

 conspicuous measure be brought out is by hybrid- 

 izing species that have so far diverged that they 

 lie almost at the limits of atlinity. By such union 

 of hereditary factors that have long been dis- 



[191] 



