FUNGI OF IMPORTANCE IN THE DECAY OF TIMBERS. 35 



affected, practically 100 per cent germination resulting, while the 

 chlamydospores did not germinate at all. 



LIGHT. 



The diffused light from an east window during the winter appar- 

 ently had little effect on the germination of the secondary spores. 

 The oidia of Lenzites sepiaria and L. trabea germinated almost per- 

 fectly in diffused light or in the dark, although the development was 

 somewhat more rapid in the dark. The same is true of chlamydo- 

 spores of Trametes serialis, except that the percentage was between 

 50 and 60 rather than around 100.' 



In the month of May, 10 hours of direct sunlight acting upon the 

 secondary spores upon agar not only inhibited germination during 

 that period but prevented subsequent germination altogether. Ex- 

 periments upon the killing effect of direct sunlight upon these spores 

 when resting could not be carried out, inasmuch as it was impos- 

 sible to separate the effects of drying from the effects of sunlight, 

 because, as will be shown, drying materially reduces the percentage 

 of germination. 



DRYING. 



There have been a few reports of the resistance of secondary spores 

 to drying. De Seynes (50) found that the conidia of Fistulina 

 hepatica germinated after four years. Brefeld (5, p. 153) said that 

 the conidia of Fomes annosus retained their viability for one year 

 and a few germinated after two years of drying. He also stated 

 (5, p. 27) that the oidia of Phlebia merismoides resisted drying for 

 a month and some germinated after six months. According to Falck 

 (15, p. 146) the aerial oidia of Lenzites sepiaria are resistant to dry- 

 ing. Oidia subjected to drying in the presence of calcium chlorid 

 germinated after one year, and they were not killed after an exposure 

 of several hours to 60° C. (p. 147). On the other hand, Lyman 

 (31, p. 149) concluded that in general the retention of viability by 

 oidia is of short duration. 



The writer's results with the oidia of Lenzites sepiaria and L. tra- 

 bea agree with Lyman's conclusions. Agar cultures with an abun- 

 dance of oidia and oidia on glass slides were dried for varying 

 periods. After one day of drying the percentage of germination 

 was much reduced, and usually to less than 1 per cent. In some 

 eases, however, a vary small percentage of oidia would germinate 

 after a few months at room temperature, perhaps because of pro- 

 tection of certain oidia by large masses of others. It was thought 

 (that if any resistance to drying should he manifested if would be 



on the oatural substrate for the fungus, but the results were the 

 same as on agar. 



