440 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 3 8 



are now so prevalent in this zone. At present there remain in this 

 low-elevation belt only scattered remnants of the extensive forests 

 that existed prior to the advent of the white man. This slow but 

 inevitable utilization and destruction of the relatively few remaining 

 low-elevation trees of superior heredity is still going on, and so it 

 behooves us to test as rapidly as possible the offspring of such of these 

 trees as still exist. For, while nearly all the trees of this strain seem 

 to yield relatively vigorous progenies, among them may be found one 

 that surpasses all others — the progenitor of a new, rapid-growing race 

 of ponderosa pine that can be grown on very short rotations. 



It is because forest genetics has often been regarded as an exceed- 

 ingly slow and unpromising line of scientific endeavor that I have 

 purposely summarized in this article some of the Institute's results 

 that point strongly in the opposite direction. It is not the intention, 

 however, to give the impression that the path of the tree breeder is 

 strewn with thornless roses. His advances are always beset with 

 difficulties, only a portion of which have as yet been overcome. Never- 

 theless, if we may be permitted to judge the future by the accomplish- 

 ments of the past, the prospects from our present vantage point are 

 very bright for bringing about, through the use of genetics, major 

 advancements in American forestry. 



