CRYPTOGAMIC PLANTS. 91 



But nowhere, perhaps, is the effect produced by 

 this cryptogamic phosphorescence so exquisitely 

 beautiful as in the mines of Hesse, in the north of 

 Germany, where the walls of the air galleries ap- 

 pear illuminated with a pale light resembling that 

 of the moonbeams stealing through narrow cre- 

 vices into some gloomy recess. 



Some other species of Rhizomorpha are sup- 

 posed to be luminous, but this is doubtful. Heinz- 

 mann says he has remarked phosphorescence in 

 It. subterranea and in R. aidulce. 



Certain experimentalists think that the light of 

 these fungi is more brilliant in oxygen gas than 

 in the air, and that it is extinguished in those 

 gases which are non-respirable ; whilst others, on 

 the contrary, have asserted that though hydrogen 

 gas, hydrochloric acid, and nitric oxide, seem to 

 put out the light of many phosphorescent fungi, 

 this light is not extinguished in pure nitrogen. 

 These observations require, therefore, to be re- 

 peated with care. 



Phosphorescence appears to have been first ob- 

 served in large fungi at Amboine, by the botanist 

 E/umphius, who saw light emitted from a species 

 he has designated Fungus igneus, or fire-mush- 

 room. It was afterwards seen in the Brazils by 

 another botanist, Gardner, upon an agaric, which 

 grows on the dead leaves of the Pindoba palm, 

 and which has been named Agaricus Gardneri. 



