CHAPTER X 



LUMINOSITY OF FUNGI 

 Several species of fungi emit a bright phosphorescent, greenish 

 hght during the night, or wlien kept in darkness. This is more 

 frequent in exotic than in British species. Sterile myceh'um in 

 decayed wood, rhi/.omorphs and sclerotia also possess the same 

 property. Corticium cceruleum, an indigo-blue fungus forming a 

 thin, satiny film on old bark, wood, etc., is perhaps our best example 

 of a phosphorescent fungus, but examples of such mycelium and 

 fungi are not uncommon on woodwork in mines. The following 

 account by Berkeley gives a vivid idea of what the mycelium of a 

 fungus is capable of doing in this direction. " A quantity of wood 

 had been purchased in a neighbouring parish, which was dragged 

 up a very steep hill to its destination. Amongst it was a log of larch 

 or spruce, it is not quite certain which, twenty-four feet long and a 

 foot in diameter. Some young friends happened to pass up the 

 hill at night, and were surprised to find the road scattered with 

 luminous patches, which, when more closely examined, proved to l>e 

 portions of bark or little fragments of wood. Following the track, 

 they came to a blaze of white light which was perfectly surprising. 

 On examination it appeared that the whole of the inside of the 

 bark of the log was covered with a white byssoid mycelium of a 

 peculiarly strong smell, but unfortunately in such a state that the 

 perfect form could not be ascertained. This was luminous, but the 

 light was b}' no means so bright as those parts of the wood where the 

 spawn had penetrated more deeply, and where it was so intense 

 that the roughest treatment scarcely seemed to check it. If any 

 attempt was made to rub off the luminous matter it only .shone 

 the more brightly, and when wrapped up in five folds of paper 

 the light penetrated through all the folds as brightly as if the 

 specimen \\-as exposed. When, again, the specimens were placed 

 in the pocket, the pocket when opened was a mass of light. The 

 luminosity had now been going on for three days." 



A satisfactory explanation of the phenomenon is not forthcoming. 

 The light is brightest in those portions of an agaric where growth is 

 most vigorous 



CHAPTER XI 



FOSSIL FUNGI 

 Some of the primitive forms of fungi are geologically of great 

 antiquity, having been found in the tissues of plants from the Lower 

 Carboniferous and Permian rocks. Members of the Agaricaceae 

 and the Polyporaceae have been found in Tertiary formations. 



Altogether, just over four hundred species of fossil fungi have 

 been described and figured. 



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