STUDIES ON THE LUMINOUS FUNGUS. 27 



var. Sieboldl Maxim.), which is the only host as yet known. It 

 is fonnd in the Autumn. 



3. The light is emitted by the gills only ; all other parts of 

 the fungus, including spores, are not luminous. The gills are uni- 

 formly luminous all over. Both hymenium and trama of gills are 

 luminous. The juice squeezed out from the luminous .gills are 

 non-luminous. 



4. The minimum and maximum temperatures in which the 

 present fungus emits light are 3 — 5°C. and 40°C. respectively. 

 The optimum temperature may be put down at 10 — 15°C. 



5. In nitrogen gas, the luminosity begins to fade after ten 

 seconds, becomes very feeble after fifty seconds, is scarcely re- 

 cognizable after one minute and twenty seconds, and finally be- 

 comes completely invisible after one minute and forty seconds. 

 In. hydrogen gas, it begins to fade after ten seconds and becomes 

 invisible in thirty minutes. In ether vapor, the light becomes 

 invisible after one minute and fifty seconds, and if immediately 

 after that, the object be taken out into the air, the luminosity 

 returns after thirty seconds. In chloroform vapor, it vanishes 

 in fifty-five seconds. 



Exposure to oxygen gas causes no change in the luminosity. 

 Gills with faded luminosity become temporarily highly luminous 

 some minutes after being in gaseous ether or chloroform. 



6. The fungus with luminous area of about 100 sq. cm. gives 

 sufficient light for seeing Roman alphabets of about 8 mm. dia- 

 meter in the dark. The luminosity can be fully perceived at a 

 distance of thirty metres or more. 



7. The light is white in color, not greenish, bluish or yel- 

 lowish as in almost all other cases of luminous fungi. Photographic 

 images of the luminous surface of the fungus taken in the dark 

 room, by exposure of seven and half hours and also of twenty- 



