24 



THE WHITE PINE 



exert an undoubted influence on the mixture 

 and topographic distribution of species. 



Hemlock lumber is of great commercial im- 

 portance in Pennsylvania, and is rapidly gain- 



FlG. 1. 



0 10 20 30 40 Years. 



WMte Pine. 



Norway Pine. 



Pitch. Pine. 



Hemlock. 



ing ground. A study of the silvicultural char- 

 acter of the tree, and the construction of yield- 

 and volume-tables for it, would probably be of 

 much use. Since nearly pure Hemlock forest 

 exists over large areas, the construction of such 

 tables would present no difiSculty. 



