CHAPTER XII 



THE BIOLUMINESCENCE OF PANUS STYPTICUS 



Introduction — The Length of 'Spores of English and North American Origin — 

 The Divergence of Imbricating Fruit-bodies — Retention of Vitality after 

 Desiccation and during Frost — First Observations on the Bioluminescence of 

 Pamis sfypticus — Nomenclature of the Two Physiological Forms — A Simple 

 Mode of Demonstrating Bioluminescence with a Plant — The Phenomenon of 

 Bioluminescence with Special Reference to Fungi — Further Observations on 

 the Bioluminescence of Panus stypticvs luminesce ns — Photographs made with 

 the Light of the Gills — -The Emission of Light by the Mycelium — A Photograph 

 made with the Light of the Mycelium — Dependence of Luminescence on the 

 Presence of Moisture — Dependence on Oxygen — Effect of Anaesthetics — 

 Effect of Temperature — Evidence Proving the Existence of Luminous and 

 Non-luminous Forms of Panus sfypticvs — Hyphal Fusions between the Two 

 Forms — Geographical Distribution of the Two Forms — Luminous and Non- 

 luminous Forms of Xylaria Hypoxylon — The Bioluminescence of Decaying 

 Leaves — Persistence of Luminescence in Leaves — Photographs made with the 

 Light of Luminous Leaves — Remarks on the Bioluminescence of Armillaria 

 mellea 



Introduction. — Panus stypticus is a wood-destroying fungus. Its 

 fruit-bodies are often found in groups or imbricating clusters on 

 the dead stumps or logs of oaks, birches, alders, and other trees 

 both in Europe and North America (Fig. 159). I myself have 

 gathered this Hymenomycete in England and in eastern and central 

 Canada. 



In a typical fruit-body (Figs. 160 and 161) the stipe is lateral, 

 short, compressed from above downwards, usually ascending, dUated 

 on approaching the pileus, and paler than the gills ; while the pileus 

 is 0-5-1 -5 inches in diameter, reniform, thin but soft, cinnamon 

 becoming pale, and with the cuticle on its upper surface broken up 

 into minute scurfy squamules. The gills end sharply at the top of 

 the stipe and are therefore not decurrent, and they are 1-1-5 mm. 



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