16 



THE CONIFERS OF THE NORTHERN ROCKIES. 



ing moisture. When this condition has been reached other trees are 

 able to maintain a foothold, and being more tolerant of shade than 



FIG. 6. White Pine, on Priest River, northern Idaho. Tree over 3 feet in diameter; 

 young Western Hemlocks in the foreground. July. 



the pines, grow up among them and gradually crowd them out. 

 The grass and the first growth of shrubs entirely disappear, and a 



