FUNGI OF IMPORTANCE IN THE DECAY OF TIMBERS. 



25 



III. Chlarnydospores present, but no oidia. 



A. Mycelium tough, brownish in old agar cultures; with abortive fruit 



bodies, especially in plate cultures ; covers 10-cin. Petri dish in 12 days 

 at 28° C. ; aerial chlarnydospores often showing contraction of the 

 protoplasm and formation of thick secondary walls ; usually having a 

 strong aromatic odor Lentinus lepideus. 



B. Mycelium white ; no abortive fruit bodies ; covers 10-cm. Petri dish in 



seven days at 28° C. ; chlarnydospores more abundant in submerged 

 mycelium Trametes serialis. 





EFFECT OF TEMPERATURE ON THE GROWTH OF THE MYCELIUM. 



The tests on the effect of temperature upon the growth of the my- 

 celium were made on malt agar in 10-centimeter Petri dishes. The 



<P3 



8 /6 29- &Z 



<?o 



1<"ig. 



-Effect of temperature upon the growth of the mycelium upon malt agar (shown 

 in millimeters of radial growth from the inoculum). 



inoculum consisted of a block of agar 8 to 10 millimeters square, with 

 its mycelium, cut from the young growth of a previously prepared 

 Petri dish culture. This transfer was deposited upon the surface 

 of the agar in the center of the dish. Growth was measured in 

 millimeters radially from the edge of the inoculum. The results of the 

 tests upon the five fungi are given in figure 2 and in Plate VII. For 

 Lenzites sepiaria the optimum lies at 30° to 34° C. (85° to 93° F.). 

 At '.', and 8° C. (37° and 46° F.), there was no noticeable growth 

 in 8 days, and after a month there was no growth at 3° C. and 

 only a millimeter or two at 8° C. At 40° C. (104° F.) results varied. 

 < )ccasionally there was no noticeable growth until a liter L8 days, when 

 it railed from 1 to 3 millimeters ; at other times 1 to 5 millimeters was 

 evident, in 8 days. No grout h took place ai 14° C. (Ill F.). Falck 

 (16, pp. 127 L29) obtained somewhat different results for this fungus. 



