410 



RESEARCHES ON FUNGI 



12 hours. During this period the fruit-bodies shed an abundance 

 of spores on the plate but, when the plate was developed, the film 

 was found to be uniformly white, thus showing that it had not been 

 affected by light coming from the fruit-bodies. The experiment 

 was repeated, but again with negative results. Even photo- 

 graphically, therefore, Dr. Corner was unable to obtain any evidence 

 that the English Panus stypticus gives out light.^ 



In December, 1922, when visiting Dr. Corner at Great Missen- 



den, I collected a number 

 of fresh fruit-bodies of 

 Panus slypticus from a 

 stump in a wood and let 

 them dry out on a table. 

 Subsequently, I took 

 them to Winnipeg. On 

 March 8, 1923, the fruit- 

 bodies were allowed to 

 absorb water through 

 their pilei. They revived, 

 appeared perfectly vigor- 

 ous, and, within a few 

 hours, began to discharge 

 spores in vast numbers ; 

 but, to the eye, in a dark 

 room, they were entirely 

 non-luminous. Some six or seven of the fruit-bodies were placed, 

 with the pilei downwards, upon a clear glass j)late and this was 

 then set upon a very sensitive photographic plate with the film 

 turned upwards. This preparation, after being covered to prevent 

 the fruit- bodies from drying up, was left in the dark room for 24 

 hours. During this period the pilei formed heavy white spore- 

 deposits on the clear sheet of glass (Fig. 174); but they in no 

 way affected the photographic plate beneath, for when this was 

 developed as a negative it was uniformly white. 



The exjieriments of Dr. Corner and of myself with photographic 

 plates strongly support the view that the fruit-bodies of the English 



1 In litt. 



Fig. 174. — Panus stypticus p. f. yion-luminescens . 

 Spore-deposits made by fruit-bodies resting on 

 a sheet of clear glass which covered a photo- 

 graphic plate for 24 hours in a dark-room. The 

 plate, when developed, showed no signs of 

 having been affected by the fruit -bodies. 

 Photographed in direct sunlight against a 

 black background. Natural size. 



