VEGETABLE LAMPS. 133 



the parts of the wood which were most luminous were not 

 only deeply penetrated by the more delicate parts of the 

 mycelium, but were those which were most decomposed. It 

 is probable, therefore, that this fact is an element in the case 

 as well as the presence of fungoid matter." 



Any one who has wandered among old tree-trunks in 

 search of insects, or been a careful observer in underground 

 nooks and corners, must have seen the white tangles, often 

 of beautiful shape, which constitute the forms of some 

 fungi. They are frequently to be seen under old boards in 

 frost-like designs of great delicacy, and many of these are 

 supposed by some to have a certain relation to luminous 

 woods. Around old tree-stumps, the decayed arms of the 

 oak especially, long, cylindrical, flexible branches with a hard 

 bark covering are often found. When freshly broken, the 

 interior is pure white, later changing to a more or less deep 

 brown tint. The white, flocculent extremities form the 

 mycelium of the fungus known as Mhizomorpha subterranea, 

 one of the most interesting of the luminous plants. Its 

 mystic light is often seen in caves, where the rootlets have 

 made their way, gleaming with a soft phosphorescence. 



In coal-mines this plant is quite common, and has been 

 especially observed near Dresden. Ehrman speaks in enthu- 

 siastic terms of these " vegetable glow-worms," as he calls 

 them, which he observed gleaming on the walls and in the 

 crevices of Swedish mines. 



In Bohemia the caves are not uncommonly illumined by 

 this interesting cryptogam ; and, according to Phipson, suffi- 

 cient light has been emitted in English coal-mines from this 

 source to enable miners to read ordinary print. In the 

 mines of North Hesse, Germany, the conditions are particu- 



