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BELL SYSTEM TECHNICAL JOURNAL 



of the previous temperature tests were confirmed and the weight losses 

 due to decay by the three additional fungi, which are known to tolerate 

 higher temperatures, were as follows: 



These results indicate that certain fungi are able to bring about decay 

 of wood over a wider temperature range than others. It is clear that a 

 complete statement cannot be made until the effects of various tempera- 

 tures between 0°C. and 21°C. have been ascertained. In the light of results 

 with Lentinus lepideus, Lenzites sepiaria, and Lenzites trabea showing con- 

 siderable decay at 35°C., the upper limits of temperature should be deter- 

 mined for these fungi. 



Humphre}^ and Siggers,'^ 1933, studied the effects of different temperatures 

 on the growth of sixty-four fungi. Two different nutrient substrates were 

 used, but the optimum temperature with these rarely differed by more 

 than 2°C. The following summary shows a comparison of their results 

 with those obtained in the above tests: 



Menilius lachrymans . 



Poria incrassata 



Lentinus lepideus. . . . 



Lenziles trabea 



Lenziles sepiaria .... 



* Bottle method used; no test has been made yet with soil. 



Two of the fungi, Merulius lachrymans and Lentinus lepideus, brought 

 about decay at limits higher than those reported for cessation of growth 

 by Humphrey and Siggers. Poria incrassata had the same limiting tem- 

 perature in both tests. The temperatures for maximum growth and maxi- 

 mum decay check rather well in both tests. 



Field Studies 



The rapid decay obtained in the foregoing laboratory experiments based 

 on the soil technique was further evaluated by investigating the rapidity 

 of decay in the held. 



