364 RESEARCHES ON FUNGI 



conjragosa} and some other lignicolous Hymenomycetes, is often 

 broken into two parts in such a way that some of the spores 

 are shed in October or November and the others in March or 

 April. 



First Observations on the Bioluminescence of Panus stypticus. 

 — In 1901. Atkinson, 2 describing Panus stypticus, said: "When 

 freshly developed the plant is phosphorescent." Molisch,^ in 1904, 

 in a work which he published on light-producing plants, mentioned 

 Panus incandescens (which grows in Australia) as being luminescent, 

 but not P. stypticus. 



In 1910, with a view to investigating the alleged " phosphor- 

 escence "^ of Panus stypticus, I procured some freshly-grown fruit- 

 bodies of this species from a stump at Montreal, allowed them to 

 dry up, took them to Winnipeg and there, six weeks after they had 

 been gathered, moistened the upper surfaces of their pilei with wet 

 cotton wool. 



Six and a half hours after the fruit-bodies had been moistened, 

 they were found to have revived. The pilei were much swollen, the 

 gills fully extended, and great numbers of spores were being dis- 

 charged by the hymenium. On taking the revived fruit-bodies into 

 a dark room, I perceived at once that they were strongly lumi- 

 nescent. The luminescence was most brilliant on the under surface 

 of the pileus where the gills were developing and setting free their 

 millions of spores ; but the upper surface also gave out light, 

 although less strongly. The shedding of spores and the exhibition 



1 These Researches, vol. ii, 1922, pp. 116-117. 



2 G. Atkinson, Studies of American Fungi, Mushrooms, edible, poisonous, etc., 

 Ithaca, U.S.A., 1901, p. 1.36. 



3 H. Molisch, Leuchtende Pflanzen, Jena, 1904, pp. 28-29. 



* The word phosphorescence has been used in a loose manner to indicate all kinds 

 of luminescence, particularly that of phosphorus and of luminous animals and plants. 

 For physicists, phosphorescence means the absorption of radiant energy by sub- 

 stances which afterwards give out the energy as light. For animals and plants we 

 ought therefore to speak not of phosphorescence but of luminescence. There is no 

 reason to suppose that the luminescence of plants and animals is caused in these 

 organisms by the presence of the element phosphorus. For a classification of 

 luminescences, according to the means of exciting the light, vide E. N. Harvey, The 

 Nature of Animal Light, Philadelphia and London, 1920, p. 2.3. Chemiluminescence 

 is the production of light during a chemical reaction at low temperatures. Oxygen 

 is required for the process. Bioluminescence and chemiluminescence are essentially 

 similar phenomena. 



