64 Seaver: Studies in pyrophilous fungi 



New York Botanical Garden. As it had been some time since 

 the fungus had been under cultivation at the Garden, the spores 

 were apparently not very numerous in the air, for after several 

 days the plant failed to appear. Search was then made for some 

 recently collected spores for inoculation. No attempt had been 

 made to keep the spores for this purpose and the youngest speci- 

 mens available in the herbarium of the Garden had been collected 

 nearly three years before. The soil was inoculated with these 

 aged spores, and within a few days a good growth of Pyronema was 

 produced, the infection apparently proceeding from the point of 

 inoculation. As this experiment did not prove with certainty 

 that the old spores germinated, it was decided to test them out in 

 hanging drop culture. 



A complete history of the specimen used in the above experi- 

 ment is as follows. In the spring of 1909, a pile of leaves and brush 

 was burned, and this opportunity was taken to test the growth of 

 Pyronema under natural conditions, as the fungus was at that time 

 under cultivation in the laboratory. Spores were taken from the 

 plants grown in the laboratory and with these the burned place 

 was inoculated. In a reasonably short time our burned place 

 showed a good growth of the fungus. One good specimen was 

 collected and placed in the herbarium of the Garden in an ordi- 

 nary paper packet. In January 1912 the spores from this speci- 

 men were used for the experiment described above, and while 

 many of the spores failed to germinate, there was enough growth 

 in a hanging drop culture to form a web of mycelium over the 

 cover glass on which the spores were planted. 



The spores of Pyronema are rather thin-walled and are not 

 the kind of spores, so far as general appearance is concerned, 

 that would be expected to keep their viability for a long period 

 of time. Also, it would naturally be thought that spores which 

 are adapted to withstand long periods of unfavorable conditions 

 as resting spores would not germinate readily when fresh. The 

 spores of this fungus are an exception in both of these particulars, 

 for the fresh spores germinate very readily in hanging drop cul- 

 ture and very old spores germinate with equal facility; also, the 

 walls of the spores do not appear to be thicker than the walls of 

 the young mycelium and show no protective structures. 



