BIOLUMINESCENCE IN PANUS STYPTICUS 365 



of luminescence continued for from 10 to 14 days. At the end of 

 this time, the fruit-bodies began to go mouldy. 



At my request, Mr. W. B. Grove was good enough to send me 

 two lots of fruit-bodies of Panus stypticus which he had gathered 

 in England. One lot had been kept dry for five years, whilst the 

 second lot had been recently gathered in the month of December. 

 Upon arrival in Winnipeg, all the fruit-bodies were moistened upon 

 their upper surface with wet cotton wool in the usual manner. 

 The five-year-old fruit-bodies failed to revive and soon went 

 mouldy : they had evidently lost their vitality. Of the recently 

 gathered fruit-bodies, one did not uncurl properly, a second came 

 to have wet discoloured gills, and a third revived in a normal 

 manner. The first two fruit-bodies neither shed spores nor became 

 luminescent, and had evidently lost their vitality. The third was 

 still living, for it resumed its spore -liberating function, although not 

 very vigorously ; but it never gave out any light and soon died. 

 There seems to be no doubt that these three fungi, which were 

 gathered, as already stated, in December, were old and practically 

 exhausted before being removed from their substratum. 



The observations just recorded taught me that Panus stypticus 

 as it occurs in North America is a luminous fungus, but left me in 

 doubt whether Panus stypticus as it occurs in Europe gives out 

 light or not. 



Since 1910, from investigations made upon several collections of 

 the fungus gathered in North America and England, I have come 

 to the following conclusions : (1) the mycelium and fruit-bodies of 

 Panus stypticus of North American origin are luminous, and (2) the 

 mycelium and fruit-bodies of Panus stypticus of English origin are 

 non-luminous. The evidence supporting these conclusions will be 

 adduced in a subsequent Section. In the meanwhile the reader should 

 bear in mind that, whenever the luminosity of Panus stypticus is 

 mentioned, it is the North American and not the English strains 

 of the fungus that the author has in mind. 



Nomenclature of the Two Physiological Forms.— Of the species 

 Panus stypticus there are evidently two forms, morphologically 

 alike but physiologically different, occupying separate geographical 

 areas and kept apart by the great barrier of the Atlantic Ocean. 



