26 ART. 3. SEIICH1 KAWAMÜIiA : 



In order to take a photograph of the luminous side of the 

 fungus, a camera provided with dry-plate of the same sort as 

 above was properly arranged in the dark room. The image ob- 

 tained after an exposure of seven and a half hours, was a very 

 weak and obscure one. Even twenty -four hours' exposure under 

 the same procedure gave no better result. The obscurity of the 

 image obtained may partly be due to the fact that the gills had 

 moved, owing to growth during the long period of exposure. 

 Nevertheless, it seems the light is scarcely strong enough for suc- 

 cessful photographing with camera. Molisch's experiments^ with 

 Bacterium phosphoreum have shown that the light of that bacterium 

 is sensible enough to dry-plates by one second's exposure, and 

 that even its reflection can be caught by the dry-plate, so that 

 the printed surface of a book could be clearly photographed by 

 its shine after twelve hour's exposure. It is plain that the photo- 

 sensible power of the light of Bacterium phosphoreum light is very 

 much stronger than that of Preurotus japonicus. 



XI. Summary. 



The chief result of my observations on Pleurotus japonicus 

 may be summarized as follows : 



1. The fungus belongs to the genus Pleurotus, being charac- 

 terized by the position of stem at one side of pilous, by the de- 

 eurrent gills, by the spores presenting white color when caught in 

 a mass, &c. It somewhat resembles Pleurotus rapiclus Kalchbr. 

 and Pleurotus ostreatus Jacq., but apparently represents a new and 

 distinct species. 



2. The fungus usually grows in clusters, overlapping one 

 another, on the decayiug trunk of the beech (Fagus sylvatica L. 



1) Moliscb, H., Leuchtende Pflanzen, \>. 136, 1904. 



