16 AKT. 3. — SEIICHI KAWAMUKA : 



instance of the experiments was the increscenee of luminosity 

 brought about by changes of air temperature. The recovery of 

 suppressed luminosity was speediest at a temperature of 10 — 15 C C. 



The changes of the fungus-light were more rapid and intense 

 in water than in air at the same temperature. Water, being a 

 better conductor of heat than air, transmits heat more rapidly to 

 the plant. This fact, together with the limited supply of oxygen 

 in water, goes to make the changes in that medium more rapid 

 than in air. In water of 30 — 35°C. temperature, the fungus retains 

 the power of recovering suppressed luminosity. In that of 40°C, 

 the light loses itself in the superficial parts in direct comtact with 

 the hot water and that permanently, though the internal parts 

 continue to emit light for some time and may recover the power 

 after temporary loss. So, 40 C C. may be taken as the critical 

 temperature, at and above which the fungus permanently loses its 

 luminous power. 



It scarcely needs to be pointed out that the results are greatly 

 influenced by duration of exposures as also by certain other cir- 

 cumstances. The limited supply of oxygen in water has probably 

 much to do with the relatively quick fading "of the fungus light. 

 As a general matter, the fungus dipped into water of 10 — 1.5°C. 

 did not lose its luminosity for a period as long as an hour, while 

 in water of -10 — 0°C. and of 50 — 60°C. it lost the luminosity 

 within a few seconds or a few minutes at the longest. 



De Vpjes 15 and others stated that the parenchyma of many 

 phanerogams, mosses and algae is killed either by heating to 43 



— 47 C C. in water and to 51°C. in air or by cooling to -6 9°C. 



in air. If that be so, it may be assumed that the fungus pieces 

 used by me in the experiments were killed in those cases in which 



1) De Vries, EL, Matériaux pour La connaissance de l'influence de la température sur les 

 plantes, 1870, p. 3 (reprint from Archives Néerlandaises &c, t. IH.) 



