Weir: Introduction of Wood-Destroying Fungi 63 



temperatures vary around 40° to 60° F., several species grew 

 luxuriantly. It is known that the coldest weather in northern 

 climates is not sufficient to destroy the vitality of sporophores of 

 tree fungi, in fact BuUer® has shown that certain species will with- 

 stand the temperature of liquid air ( — 190 deg.) for protracted 

 periods. Westerdijk^ advances the view that the tropical tem- 

 perature is too high for many fungi, and states that in her labora- 

 tory over 600 fungi are cultivated, and this collection shows 

 cleary that the temperature of optimum growth of the greater 

 part of the fungi Hes below 30° C, often under 25° C. An ex- 

 posure to high temperature prevents many parasites from forming 

 their spores or fruiting bodies, whereas others require a change 

 of temperature for normal growth. The Polyporaceae, for in- 

 stance, bear exposure to frost very well, but many of them scarcely 

 develop at 30° C. That the low winter temperatures of northern 

 climates will not affect the vitality of at least some tropical w^ood- 

 destroying fungi is shown by the following experiment. During 

 the winter of 1909, the writer took a section of a tree branch on 

 which were two or three small sporophores of Polystictus san- 

 guineus Fr. from the mycological collection at the University of 

 Munich, and placed it on the ground in the forest among other 

 branches of native Alnus bearing sporophores of Polystictus 

 hirsutus Fr. The branch had been in the collection about two 

 years and had been collected in the low lands of Brazil. Very 

 early in the following spring, while snow was still on the ground, 

 the sporophores of the native fungus started growing. A week 

 later the tripical species revived, and before the end of spring not 

 only had produced a new hymenium but enlarged its hymenial 

 surface to about one fourth of its original size, and one entirely 

 new but small sporophore was produced. Sporophores of Poly- 

 stictus occidentalis (Klotzsch) and P. inaxima (Mont.) from the 

 warm zones of Cuba attached to their substrata were exposed to 



8 Buller. Upon the vitality by dried fruiting bodies of certain Hynieno- 

 mycetes, including an account of an experiment with liquid air. Trans, of 

 the British Mycological Society, 112. 1912. 



Also Buller and Cameron. On the temporary suspension of vitality in the 

 fruit bodies of certain Hymenomycetes. Trans, of the Royal Soc. of Canada. 

 Third Ser. 6: 73-75- 1912. 



9 Westerdijk, Johanna. Loc. cit. i. 



