FUNGI OF IMPORTANCE IN THE DECAY OF TIMBERS. 33 



tests. This method was not entirely satisfactory, but was the best 

 that could be used in view of the lack of chlamydospores in quantity 

 on the aerial mycelium. This method would not produce results 

 with the chlamydospores of Lentinus lepldeiis, however, because they 

 could not be separated from the mycelium, which appeared to be 

 rather tough. The spores were not abundant in the first place, and 

 germination tests on the few obtained were unsatisfactory, because 

 the mycelium in the macerated mass overgrew the germinating 

 chlamydospores. 



All of the secondary spores germinate readily on various agars or 

 in tap water. In distilled water numerous tests have shown that 

 the oidia germinate sparingly (usually less than 1 per cent and 

 produce only a small amount of attenuated mycelium. The chlamydo- 

 spores could not fairry be tested in distilled water, on account of 

 the difficult}- in obtaining the spores free from mycelium, agar, etc., 

 as explained above. On red spruce the secondary spores germinate 

 normally as to time and manner, although forming attenuated 

 mycelium. 



TEMPERATURE. 



The curves shown in figure 3 represent the effect of temperature 

 upon the germination of oidia of Leneites sepiaria and L. trabea 

 and the chlamydospores of Trametes serkdis. It will be noted that 

 most of the oidia of both species germinated even at the extreme 

 temperatures. At 5° C. (22° F.) in 5 days only 35 per cent of the 

 oidia of L. sepiaria had germinated, 75 per cent in 11 days, and 80 

 per cent in 14 days. At 44° C. (111° F.) the oidia of both L. sepiaria 

 and L. trabea germinated to practically 100 per cent in 20 hours. 

 The oidia of L. sepiaria germinated most rapidly at 36° C. (97° F.) 

 and that of L. trabea at 32° C. (89° F.). 



About 7"> per cent of the chlamydospores of Trametes serkdis ger- 

 minated between 20° and 32° C. (68° and 89° F.). In three weeks 

 y>~> per cent germinated at 50° C, but none germinated at 36° in re- 

 peated tests. The rate of development was optimum around 28° 

 and 32° C. (82° and 89° F.). 



A '•omparison of the cardinal temperatures for rate of germina- 

 tion of the basidiospores and secondary spores witli growth of the 

 mycelium of the five fungi studied shows that they correspond quite 

 closely. The optimum for basidiospores extends over a little wider 

 range of temperature than for (lie secondary spores or mycelium. 

 The maximum temperature for the germination of (lie basidiospores 

 is somewhat higher, by a few degrees, than for the, growth of the 

 mycelium of all five fungi. The oidia of Len&ites sepiaria and /.. 



