382 RESEARCHES ON FUNGI 



well be that it is only owing to some difficulty in extraction that 

 at present these substances have not been shown to exist in 

 any fungus. Ewart^ using Pleurotus candescens, Kawamura^ using 

 Pleurotus japonicus, and I myself using Partus stypt. Inminesceiis, 

 have each found that the juice extracted from a luminous fruit- 

 body is non-luminous. 



For luminous organisms in general, including Panus stypt. 

 luminescens, Pleurotus japonicus, and other luminous fungi, it appears 

 from the facts already brought forward that Molisch was right in 

 postulating a photogen, and that the photogen has a dual nature 

 in that it consists of luciferin, which is thermostable, and of the 

 enzyme luciferase, which is thermolabile. The interaction of 

 analogous pairs of thermostable and thermolabile substances is re- 

 quired in some other biological processes, e.g. the alcoholic fermen- 

 tation of glucose by the zymase of Yeast juice, where a thermo- 

 stable co-enzyme and the enzyme proper, which is thermolabile, 

 are both required for fermentation to be carried on.^ 



When luciferin in oxidised, it is converted into oxyluciferin. 

 Under the influence of reducing agents oxyluciferin becomes reduced 

 and the luciferin is regenerated. In this connection Harvey says : 

 " We may quite logically believe that the bacteria and fungi oxidise 

 luciferin in one part of the cell and reduce oxyluciferin in another, 

 while the animal organisms oxidise luciferin during the flash and 

 reduce it between flashes. Should this be true, and it is not proven 

 as yet, living processes would present a marvel of economy quite at 

 variance with the prodigality we are apt to associate with repro- 

 ductive nature." ^ 



Luciferase, according to Harvey,^ " is unquestionably a protein 

 and all its properties agree with those of the albumins. Although 

 used up in oxidising large quantities of luciferin, it behaves in 

 many ways like an enzyme and may be so regarded." Luciferin, 



^ A. J. Ewart, " Note on the Phosphorescence of Agaricus {Pleurotus) candescens 

 Miill." The Victorian Naturalist, vol. xxiii, 1906, p. 174. 



^ S. Kawamura, loc. cit., p. 9. 



3 E. N. Harvey, The Nature of Animal Light, 1920, p. 104. 



^ E. N. Harvey, " Animal Luminescence," Journal of the Franklin Institute, July, 

 1923, pp. 38, 41. 



5 E. N. Harvey, The Nature of Animal Light, 1920, pp. 141-142. 



