96 PHOSPHORESCENCE IN 



It is quite possible, however, that the syno- 

 nyms given above refer to more than one plant ; 

 it is very probable also that many byssoid fungi 

 are luminous in the dark, and that this phospho- 

 ric property pertains to many other cryptogams. 

 Adrien de Jussieu, in his ' Elements de Bota- 

 nique/ remarks that certain kinds of wood become 

 phosphorescent when they are exposed to the 

 damp after they have been cut in full sap. The 

 phosphoric light emitted in this case appears to 

 be owing to one of the byssoid fungi just named. 



No Algce have, if I mistake not, been described 

 as phosphorescent, although many whilst grow- 

 ing under water reflect colours which perish al- 

 most immediately when the plant is removed to 

 the air. Of this class are several species of Cysto- 

 seira, especially 0. ericoides, which, though really 

 of a greenish-olive, appears when growing under 

 water to be clothed with the richest phosphoric 

 greens and blues, changing momently, as the 

 branches move to and fro in the water. Similar 

 colours, according to Harvey, have been observed, 

 though in a less striking degree, on some of the 

 RedAlgce, and the genus Iridcea derives its name 

 from this phenomenon. Clwndrus crispus is ob- 

 served to be occasionally iridescent, and at the 

 Cape of Good Hope Ghampia compressa and Cliy- 

 locladia Capensis present very brilliant rainbow 

 colours, etc. "The cause of these brilliant co- 



