PANUS STYPTICUS 



3^3 



not only a high degree of desiccation but also intense frost. They 

 soon recover after having been subjected for a night to a tempera- 

 ture of —10° C. Frost, as well as drought, may therefore tem- 

 porarily interrupt the production and liberation of spores. The 

 resistance of the fruit-bodies of Panus styptiais to frosts which are 



Fig. 162. — Panus stypticus physiological form luminescens. 

 Fruit-bodies obtained in dry weather, with edges of the 

 pileus curled downwards and inwards, thus partially 

 covering up the hymenial surface. A, imbricating fruit- 

 bodies on a piece of wood from the side of a stump. 

 B, fruit-bodies seen from above. C, fruit-bodies seen 

 from below. Collected at Ottawa by W. S. Odell. Photo- 

 graphed by the Photographic Division of the Geological 

 Survey of Canada. Natural size. 



fatal to many soft-fleshed agarics accounts to some extent for the 



fact that this fungus flourishes late in the autumn. 



It is probable that, in the colder parts of Canada and the 



United States, owing to an interruption caused by the intense 



cold of the mid-winter months, the spore-discharge period of 



Panus stypticus, like that of Schizophyllum commune,^ Daedalea 



^ At Winnipeg, where the winter is long and comes and goes rather suddenly, 

 the fruit-bodies of Schizophylhim commune often become frozen before they are 

 exhausted. Such frozen fruit-bodies, when brought into a warm laboratory in 

 mid-winter, quickly thaw and, if kept moist, soon begin to emit a cloud of spores. 

 I have no doubt that such fruit-bodies, under natural conditions, shed some of their 

 spores in the autumn and the remainder in the following spring. Cf. these Researches, 

 vol. i, p. 127. 



