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AMERICAN FORESTRY 



Plate No. 1. — Properly Treated Injuries, Showing NoriMal Healing, and Untreated 

 Injuries, Showing Normal Progress of Decay. 



Fig. 1. — Cross section of a tree trunk showing location of parts: a, heartwood; b, sapwood; c, 

 cambium; d, bark; e, corky outer bark. Fig. 2. — A scar beginning to heal over. (Note that 

 it heals more rapidly at the sides than at the top and bottom.) Fig. 3. — A scar about three- 

 quarters healed over. Fig. 4. — Cross section of a 7-year-old blaze on a quaking aspen which 

 has nearly healed over. (Note the large area of decay which originated at the ax cut. The 

 line on the wood indicates the proper shape of the cavity if this had been excavated.) Fig. 

 5. — A scar from a cut limb entirely healed over. Fig. 6. — End of a log, showing a small open- 

 ing into the large decayed area; only a shell of sound wood remains. 



