378 GENERAL BOTANY 



over four million cords of wood is used for this purpose 

 annually, of which about 60 per cent has been spruce wood. 

 Red spruce has been the principal contributor to this great 

 enterprise, but other woods are now being used on account of 

 the depletion of the American and Canadian forests in the trees 

 of this species. Spruce wood is also widely used in slack cooper- 

 age and in building and interior finishing. The great value of 



spruce wood in the 

 industries has stim- 

 ulated the govern- 

 ment to investigate 

 new methods for 

 its preservation and 

 regeneration in the 

 forests, which will 

 undoubtedly result 

 in preserving these 

 valuable trees to 

 future generations. 



THE PINES 



Habitat and habit. 



FiG.232. Transversesectionof tree trunk of long-leaf Th . originally 

 pine, showing annual rings, heartwood, and sapwood . J 



Photograph furnished by the United States Forest Service occurrecl 



mixed and pure for- 

 ests in the northern, southern, and western national forests. 

 The great stand of pure pine in the northern forests in the 

 Great Lakes region has been almost wholly depleted, however, so 

 that the southern forest of long-leaf and short-leaf pine, loblolly 

 pine, and cypress is one of the principal sources of pine lumber 

 to-day. This is also the great seat of the turpentine industry, 

 which has exacted a. heavy toll on southern pines under the 

 old wasteful system of tapping the trees for turpentine. The 

 Western Rocky Mountain and Pacific Coast forests also supply 

 pine lumber in large quantities from the western yellow, lodge- 

 pole, sugar, and white pines, which find their natural home in 



