8 A PLAIN AND EASY ACCOUNT 



of the plant, but also to the production of the green 

 chlorophyl, or colouring matter. Fungi, on the con- 

 trary, would appear to flourish best in the absence of 

 light, in dark cellars, under flagstones, in hollow trees, 

 and in like places, where no other form of plant could 

 exist ; while some genera are entirely subterranean. 



The luminosity of fungi is a phenomenon which we 

 do not often see exhibited in these temperate regions ; 

 but in countries nearer the tropics it is not at all an 

 uncommon occurrence for fungi to give out a kind of 

 phosphorescent light with sufficient intensity to enable 

 the traveller to read his letters or write up his journal. 



" And unctuous meteors from spray to spray 

 Crept and flitted in broad noonday 

 Unseen, every branch on which they alit 

 By a venomous blight was burned and bit." 



In our schoolboy days we remember to have often 

 carried home in our pockets a piece of touchwood, to be 

 taken to bed with us on account of the little light it 

 afforded. What we, in common with our elders and 

 betters, termed touchwood, was merely the light, white, 

 decaying wood of an old stump, entirely permeated with 

 the minute mycelium of a fungus, and which exhibited 

 phosphorescence in the dark. The fact was well enough 

 known to us, but the cause was a mystery ; the remotest 

 idea of its being due to the presence of a fungoid growth 

 never entered our boyish heads. 



A kind of Polyporus (P. sulfureus), often found 

 forming a dense mass on the stumps of trees, exhibits 

 phosphorescence in the early stages of its decay. 



