GENERAL SUMMARY 577 



of English origin are non-luminous. Of the species -Panus stypticus 

 there are evidently two forms, morphologically alike, but physiologically 

 different in that one exhibits bioluminescence and the other does not. 

 The author has named the luminous form Panus stypticus physiological 

 form luminescens and the non-luminous form Panus stypticus physio- 

 logical form non-luminescens. The two forms are separated geographi- 

 cally by the great barrier of the Atlantic Ocean. 



Young and vigorous fruit-bodies of Panus stypt. luminescens, which 

 have been dried, can be revived at any time within six months after 

 drying by supplying Avater to the tops of their pilei. Revived fruit- 

 bodies are luminous. The fruit-bodies of P. stypt. luminescens are 

 therefore very convenient for making laboratory demonstrations of 

 bioluminescence in a plant. 



The author reviews our knowledge of the general phenomenon of 

 bioluminescence with special reference to fungi. 



A series of experiments made with the mycelium of Panus stypt. 

 luminescens showed that, after the eyes have been exposed to strong 

 daylight for an hour or more, it is necessary for one to remain in the 

 dark room for 10-12 minutes before the light of the mycelium can be 

 perceived. Before concluding that a fungus is not luminous, one should 

 spend at least 15 minutes with it in the dark room. 



At Winnipeg, 50 per cent, of pieces of butcher's meat (beef, etc.), 

 treated with salt solution as advised by Molisch, became luminous owing 

 to the presence of luminous bacteria upon their surface. 



When a fruit-body of Panus stypt. luminescens is in a very rudimen- 

 tary condition the stipe and the whole of the pileus are luminous ; but, 

 as the fruit-body develops, the stipe ceases to give out light and the 

 luminescence becomes concentrated in the gills. Mature fruit-bodies 

 during the spore-discharge period give out light for 7-10 days. 



An attempt to extract a luminous fluid from the fruit-bodies of Panus 

 stypt. luminescens failed. The author, therefore, did not succeed in 

 determining whether or not the luminescence of the fungus is due to a 

 luciferin-luciferase reaction. 



Pure cultures of the mycelium of Panus stypt. luminescens made from 

 spores on blocks of sterilised Birch wood emitted light strongly for 

 about six months and still gave out some light at the end of a year. 



Shadow-photographs were made with (1) light emitted by the fruit- 

 bodies of Panus stypt. luminescens and (2) light emitted by the mycelium. 



The luminescence of the fruit-bodies of Panus stypt. luminescens is 

 dependent on (1) the presence of moisture, (2) the presence of oxygen, 

 (3) a certain range of temperature, and possibly also on (4) the presence 

 in the hyphae of luciferin and luciferase. 



Dried fruit-bodies of Panus stypt. luminescens begin to emit light 5-10 

 minutes after being moistened. 



An apparatus was devised for controlling the supply of oxygen to 



VOL. in. 2 r 



