STUDIES ON THE LUMINOUS FUNGUS. \) 



were always non-luminous as tested by repeated experiments. 



The above series of experiments shows that all the cells in 

 the hymenia, excepting the spores, are luminous. I have then 

 experimented with the cells of subhymenium which exists between 

 trama and hymenium. As it forms a thin zone, only one or two 

 cells thick, it was quite impossible to isolate it completely from 

 other tissues. However, since no dark stratum could ever be dis- 

 cerned underlying the hymenium in sections of the gill in full 

 illumination, I am inclined to believe that the subhymenium also 

 has luminosity. 



Desirable as it was to ascertain whether or not old and new 

 cells in each kind of the luminous tissues differed in the degree 

 of luminosity, and also if the sterigma in basidia and the younger 

 spores were luminous or not, the solution of these questions had 

 to be suspended owing to the impracticability of examining in- 

 dividual cells microscopically in the dark. On one occasion I 

 have wrapped a highly luminous gill in a piece of cloth and 

 crushed it by pressing between fingers. The crumbled mass was 

 still luminous, though the light was of a somewhat diminished 

 intensity. Then, placing the mass under a stronger pressure, a 

 small quantity of a milky juice was obtained which was not 

 luminous at all, though the residue still retained its luminosity. On 

 squeezing the mass much harder, or on crushing luminous gills by 

 grinding, the luminosity was irrecoverably lost. It seemed the 

 luminosity ceased as soon as the cell contents were freed by the 

 bursting of the wall. 



V. Effect of temperature on the fungus-light. 



(A) Experiments in the air of different temperatures. 



Method : — My first experiment was to ascertain in what 



