106 EFFECTS OF TEMPERATURE ON FUNGI 



cultures were more vigorous and produced perithecia more abun- 

 dantly than similar cultures that had been kept at normal tem- 

 peratures. 



The ability of fungi to tolerate extreme cold is illustrated by 

 Buller's (1913) findings with Schizophyllum commune and by 

 Faull's (1930) findings with Neurospora crass a. Buller exposed 

 the fructifications of 5. commune to — 190° C for 3 weeks without 

 apparent injury, and Faull subjected the ascospores of N. crassa 

 to temperatures from — 170° to — 190° C for 24 to 48 hours with- 

 out delaying their germination. When wet, the conidia of this 

 species were unimpaired by exposure to —80° C for 1 hour; when 

 dry, to —170° to —190° C for an equal period. Toleration of 

 these extremely low temperatures leads the investigator to antici- 

 pate that the spores of certain species will be found to survive 

 at absolute zero ( — 273° C), the point at which all reactions and 

 hence all biological processes are theoretically supposed to be in- 

 hibited, provided, of course, that the period of exposure is not 

 too protracted. 



Becquerel (1910) dried the conidia of Aiucor, Rhizopus, Asper- 

 gillus, and Sterigmatocvstis, sealed them in tubes under vacuum in 

 which the pressure was reduced to 10 -4 cm of mercury, and ex- 

 posed them at — 190° C for 77 hours; after 2 years' storage, they 

 germinated normally. 



In the experiments of Kadisch (1931) with several dermato- 

 phytes, Achorion gypseum survived 3 hours 1 exposure to —252° C 

 in one instance, and in another withstood 2 hours at —268° C, 

 followed by 4 hours at —268.8° C and then 1 )<> hours at —272° C. 



It would be anticipated that mycelia cannot tolerate as extreme 

 temperatures as can spores. Evidence in support of this supposi- 

 tion has been presented by Bartetzko (1910), Lindner (1915), 

 and Lipman (1937). Bartetzko (1910) subjected germinating 

 spores of Aspergillus, Penicillium, Botrytis, and Phycomyces in 

 liquid nutrient media to — 14° for 2 hours without injury. When 

 the young hyphae of Aspergillus in 1% glucose solution were ex- 

 posed to —12° for 2 hours, they were killed, whereas in 5% glu- 

 cose solution there was no apparent injury at —26° for an equal 

 period. The other species exhibited similar differences in glucose 

 solutions of different concentrations. 



Lindner ( 1915) exposed Aspergillus niger and Penicillium glau- 

 cum y growing on 3% gelatin, to —10° to —13° C. Age of the 



