400 RESEARCHES ON FUNGI 



the wash-bottle and the experimental tube containing some luminous 

 fruit-bodies, and the gas was forced through the tube by raising 

 the water-bottle. The nitrogen gas affected the luminescence of 

 the fruit-bodies in exactly the same manner as the hydrogen and the 

 carbon dioxide : when it was caused to replace the air, the light 

 of the fungi disappeared within three seconds ; and, when the air 

 was allowed to replace the nitrogen the fungi became luminous 

 immediately, and they glowed again with maximum intensity within 

 about one second after obtaining access to the air. 



Oxygen from an oxygen cylinder was caused to pass through the 

 wash-bottle c and the experimental tube e containing the fruit- 

 bodies, but no increase or decrease in the intensity of the light 

 emitted could be observed. 



It was found that diluting the air slightly with hydrogen or 

 carbon dioxide did not appreciably affect the intensity of the 

 luminescence of the fruit-bodies. Although this dilution was not 

 studied quantitatively, I think that there can be no doubt that the 

 percentage of oxygen per unit volume of ordinary air is much 

 higher than is necessary to allow the emission of light to take place 

 with its full intensity or, to state the matter in other words : the 

 limiting factor for the intensity of light-emission from the fruit- 

 bodies of Panus siypt. luminescens under natural conditions is not 

 the percentage of oxygen in the air but in all probability the amount 

 of one or other components of the photogen which, until we have 

 evidence to the contrary, we may assume to be composed of luciferin 

 and lucif erase. 



Effect of Anaesthetics. — A few experiments were made with 

 ether and chloroform. 



One cc. of ether was dropped into a 250 cc. measuring flask and 

 a stopper inserted into the neck. A luminous fruit-body was then 

 spitted upon a pin attached to another stopper. The stopper closing 

 the flask was then replaced by the stopper bearing the fungus. The 

 fruit-body, on thus becoming subjected to ether vapour, soon became 

 less luminous. The light gradually diminished and, at the end of 

 about 20 seconds, had disappeared. After the fruit-body had been 

 kept in the ether flask for another 40 seconds, it was removed to 

 the air of the room. Thereafter the light gradually returned : it 



