NATURAL ENEMIES OF THE FOREST. 



285 



the decayed tracts are tubular. More commonly the decayed parts are 

 of irregular shape. 



The decay of wood is due to the ravages of low forms of plant 

 life, both bacteria and fungi. 



A few of the more destructive forms may be noted. 



Trametes pini (Brot. ) Fr. 

 Foremost among the timber de- 

 stroying fungi is the large brown 

 "punk" or "conch" found in its 

 typical development on the long- 

 leaf and short-leaf pines, Pinus 

 palustris and Pinus ecliinata, Fig. 

 81. The fruiting bodies form 

 large masses which grow out from 

 a knot, oftentimes as large as a 

 child's head. They are cinnamon 

 brown on the lower surface, and 

 much fissured and broken, on the 

 black charcoal-like upper surface. 

 This fungus probably causes four- 

 fifths of the destruction brought 

 about by the timber destroying 

 fungi. It occurs on most of the 

 conifers in the United States 

 which have any value as lumber 

 trees, and brings about a charac- 

 teristic white spotting of the 

 wood. Fig. 82, which varies with 

 the kind of tree attacked. (Von Schrenk, Agric. Yr. Bk 



Fig. 81. A "Conch,"' the fruiting body of 



Trametes piiii^ on Sugar Pine. ^Agrte. 



Year Book, iqoo, PI. XXII, Fig. X\ 



1000, p. 206.) 



ri_ 8'' EfEeLtot F 



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