6 BULLETIN 510, U. S. DEPAETMENT OF AGRICULTURE. 



Both the fruit bodies and basidiospores vary greatly in vitality 

 among the different species of fungi. External temperature and 

 moisture conditions exert a great influence, particularly when the 

 two are working together in an unfavorable role. 



Low temperatures appear far less injurious than high temperatures. 

 Buller and Cameron ^ report gathering living fruit bodies of ScMzo- 

 phyllum commune from a woodpile at Winnipeg, Canada, in Marcli 

 at a temperature of —17° C. (1° F.), after exposure for several 

 months at winter temperatures ranging between —15° and —40° C. 

 (5° and —40° F.), After thawing for a few hours the fruit bodies 

 cast spores readily. They further report that immersing an active 

 fruit body of the same fungus in water and placing it in the open 

 over night at a minimum temperature of —31° C. (—24° F.) did not 

 suffice to kill the organism, although it was frozen into a solid block 

 of ice. 



Carrying the work still farther, Buller^ exposed fruit bodies of 

 the same fungus (previously kept dry for two years and eight months 

 in ordinary air) to the temperature of liquid air, —190° C. (—310° 

 F. ) , for three weeks in a vacuum tube. Upon removal and moisten- 

 ing, the fruit bodies were still alive and cast spores in abundance. 



In his larger work^ and certain later articles, the same author 

 shows that at ordinary temperatuies dried fruit bodies retain their 

 capacity to produce spores for long periods; for instance, Daedalea 

 unicolor can remain alive in the dark at least 8^ years and Schizo- 

 'phyllum. Gom^mune at least ^\ years. Certain others may retain their 

 vitality for only two or three years. 



In the case of temperatures above the optimum, however, the in- 

 jurious effect may become marked within a comparatively small 

 range. For instance, Falck* states that fruit bodies of Lenzites 

 ahietina fail to produce spores after five days at 26° (78° F.) and 

 the spores fail to germinate at 42° C. (108° F.). A corresponding 

 relation is also said to exist with Merulius lachrymans and other 

 species, for the same author ^ states that fresh fruit bodies of Meru- 

 lius domesticus {^^M. lachrymans in part) are killed in 30 minutes 

 at 40° to 42° (104° to 108° F.) and in 15 minutes at 46° C (115° 

 F.) ; at 42° C. (108° F.) dry spores are killed in 12 to 16 hours. 



In addition to spores produced in fruit bodies, another set of 

 reproductive l)odies is often produced directly by the mycelium. 



1 Buller, A. II. R., and Cameron, A. T. On the temporary suspension of vitality iu 

 the fruit bodies of certain Ilymenomycetes. In I'roc. and Trans. Roy. Soc. Canada, s. 3, 

 V. C, V.n-l, sec. 4, p. 7.".-78. lOi:'.. 



2 Buller, A. 11. R. Upon the retention of vitality by dried fruit bodies of certain 

 Ilymenomycetes, including an account of an experiment with liquid air. In Brit. Mycol. 

 Soc. Trans., v. 4, 1912, pt. 1, p. 100-112. 1913. 



3 Buller, A. H. R. Researches on Fungi . . . 287 p., illus., 5 fold. pi. London, 1909. 

 * Falck, Richard. Die Lenzitos-Fiiule des Coniferenbolzes. In Miiller, Alfred. Ilaus- 



Kchwammforschungen. Ilfft 3, p. r.9 and 98. 1909. 



■^ Falck, Richard. Die Mernlius-Faule des Bauholzes. In Miiller, Alfred. Ilaus- 

 8chwan)irifors(hungen. Heft (!, p. 339. 1912. 



