BIOLUMINESCENCE IN ARMILLARIA MELLEA 431 



observations made by myself at Kenora and by Dr. A. W. 

 McCallum ^ at Ottawa also yielded negative results. 



Summing up the evidence that has accumulated so far, it 

 appears that the emission of hght by the interior hyphae of the 

 base of the stipe in Armillaria 7nellea is a phenomenon which takes 

 place only under very exceptional conditions. 



It is well known that the relatively loose hyphae in the central 

 part of the stipe in agarics generally are but little specialised and 

 can readily be employed for making pure cultures. Doubtless, if 

 one were to inoculate sterihsed bread or some other suitable culture 

 medium with hyphae taken from the interior of a stipe of any 

 Armillaria fruit-body, whether obtained in North America or 

 Europe, one would soon obtain a mycelium exhibiting luminescence. 



Directions for obtaining luminous wood are as follows. In the 

 late summer or autumn, go into the forest and find a clump of 

 Arinillaria mellea fruit-bodies on a stump or log. Then with a 

 strong knife, or more easily with an axe, remove some of the sub- 

 jacent, white, mycelium-containing, rotten wood. Keejj the pieces 

 of wood damp and take them home. Examine them at night. One 

 will then readily observe them glowing with an unmistakable soft 

 whitish light. If there are no fruit-bodies in the forest, one should 

 search beneath the bark of rotten stumps for the black shoe-string- 

 Hke rhizomorphs ; for these belong to Armillaria mellea and, Hke 

 the fruit-bodies, give a clue to the presence of luminous wood. 

 Moreover, the rhizomorphs, if growing, may themselves be luminous. 



1 In litt. 



