STUDIES ON THE LUMINOUS FUNGUS. 17 



they were kept in the water of 40°C. for forty three minutes, in 

 that of 47°C. for twelve seconds, and in the air of 50°C. for 

 twenty -three minutes, — in all which cases the recovery of lost 

 luminosity did not take place. 



For the sake of comparision, I may now refer to the results 

 of other author's experiments on luminous Hymenomycetes and 

 Bacteria. As to Hymenomycetes, Arcangeli 1;) showed that Pleurotus 

 oleareus D.C. lost its luminosity in half an hour when cooled to 

 C C. After five hours lie removed the specimen into the air of 

 14 C C. and found that it could recover the lost luminosity. Another 

 specimen dipped into the water of 40°C. soon lost its luminosity ; 

 but, as soon as it was taken out of that water, the luminosity 

 was recovered ; in the water of 50°C. the fungus light rapidly 

 became invisible and did not revive on the fungus being taken out 

 of that water. A still another specimen was dipped into the water 

 of 14°C. ; the light underwent no sudden change, but gradually 

 diminished in intensity until it finally became invisible. Some 

 specimens cooled down to C C. and then slowly warmed, com- 

 menced to emit light after from three to four hours and were 

 most intense from eight to ten hours from the beginning. 



Eijkmann 2 ' observed Pseudomonous javanlcus (Eijk.) Mig. in 

 different temperatures ranging from -20 to 45°C. all the time the 

 fungus-light was clearly visible, though it was exceedingly weak 

 when the temperature fell, below 10 C C. or rose above 40°C. The 

 optimum temperature for the luminosity was determined to extend 

 from 25° to 33°C. According to Beijerink 3 , Phoiobacterium in- 



1) Arcangeli, G., Ricerche sulla Fosforescenza del Pleurotus olearius D.C., 1839. — 2) Eijk- 

 mann, C, Lichtgebende Bactérien, (Jaarverslay von het Laboratorium voor pathologische Anato- 

 mie en Bactériologie te Welteoreden over het Jaar. 1891). Overgedrukt uit het Geneeskundig 

 Jijkschrift voor Nederlandsch-Indië. Deel XXXII. Aflevering 4 Batavia en Noordwijk, p. 109- 

 115, 1892: An abstract in Zentralbl. f. Bakteriol.. XU., 1892, p. 656-657.-3) Beijerink, M. W., 

 Le Photobacterium luminosum, bactérie lumineuse de la Mer du Nord, (Archives Néerlandaises, 

 &c. t. XXm, p. 401-415, 1889). 



