106 



BELL SYSTEM TECHNICAL JOURNAL 



LENTINUS LEPIDEUS 



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FOMES ROSEUS 



PORIA MICROSPORA 



POLYPORUS VAPORARIUS 



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 2 



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2 T^^^^^'C 



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1 



PORIA INCRASSATA 



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LENZITE5 TRABEA 



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AVERAGE FOR ALL ORGANISMS 



3 

 2 



MONTHS MONTHS 



Fig. 1 — Wood soil contact technique 



