578 RESEARCHES ON FUNGI 



some fruit-bodies of Panus stypt. luminescens contained in an experi- 

 mental glass tube. It thus became possible to switch the light of the 

 fruit-bodies on and off at will. The light could be turned off completely 

 within three seconds and turned on again completely within one second. 



Exposure of the fruit-bodies of Panus stypt. luminescens to ether or 

 chloroform caused a total loss of luminescence within a few seconds. 

 Recovery of the power of giving out light took place after a one-minute 

 exposure to ether. 



The minimum temperature for luminescence in Panus stypt. lumin- 

 escens is — 2° to — 4° C, the maximum temperature 35° to 37° C, and the 

 optimum temperature about 10° to 25° C. 



The author records a series of observations which show that fruit- 

 bodies of Panus stypticus procured from various parts of England are 

 non-luminous. 



Neither the fruit-bodies nor the mycelium of Panus stypt. non-lumi- 

 nescens give out any light whatever or have any effect upon a sensitive 

 photographic plate. 



When pure cultures of (1) the mycelium of Panus stypt. luminescens 

 and (2) the mycelium of P. stypt. non-luminescens are brought together 

 in a hanging drop of nutrient agar, hyphal fusions take place between 

 them. This fact goes far to demonstrate that the two physiological 

 forms of P. stypticus do, as a matter of fact, belong to the same species. 



It is probable that the non-luminous form of Panus stypticus is not 

 confined to England but occurs throughout Europe and possibly in Asia. 



The evidence obtained by Ludwig and Guegen in France seems to 

 show that, under certain conditions, the mycelium of Xylaria Hypoxylon 

 is luminous. Since Molisch in Germany found the mycelium of this 

 fungus non-luminous, it is possible that X. Hypoxylon may consist of 

 luminous and non-luminous strains. 



Luminous leaves are commonly present in the leaf-mould of deciduous 

 forests in England, the east of Canada, and the United States. The 

 kinds of leaves observed to become luminous during their decay were 

 Oak, Beech, Sweet Chestnut, and Rhododendron. The light emitted by 

 some Oak and Beech leaves was used to make shadow-photographs. 

 When allowed to dry, luminous leaves cease to emit Hght. Such dried 

 leaves, if kept dry for 7-9 months, give out light again within about 

 3 hours after being moistened . 



Some fruit-bodies of Armillaria mellea gathered at Kenora in central 

 Canada gave out weak light from the interior hyphae of the lower part 

 of the stipe. The interior hyphae of the stipes of most fruit-bodies of 

 this species give out no light whatsoever. 



Chapter XIII. — The non-basidiomycetous fungi which are parasitic on 

 other fungi are far more numerous than basidiomycetous. and of them 

 the author gives a selected list. 



There are very few Basidiomycetes which attack other fungi and 



