DISTEIBUTION OF AMEEICAN FORESTS 



along- and carries them to a place where 

 the conditions are ill adapted to their 

 peculiar nature. The following year 

 the wind is propitious and the little 

 trees soon start into life. But presently 

 the seeds of another tree, whose growth 

 is by nature faster, are conveyed to the 

 same spot, and the intruders outstrip 

 the others in rapidity of growth and 

 spread a canopy of foliage that screens 

 the smaller trees from the life-giving 

 sun and dooms them to destruction. 

 Thus only a few of the numberless 

 seeds that are produced each year live, 

 and fewer still are able to maintain or 

 extend the ])oundaries of the parent 

 tree. Sometimes, too, the frugality or 

 hardiness of a species ma}^ be the rea- 

 son for its exclusive occupation of a 

 certain locality, since other trees may 

 85 



