288 FIRST FORMS OF VEGETATION. 
them with animals, is their luminosity. This quality 
is very rare among plants, and is almost peculiar 
to the lowest orders of animals, particularly those 
which inhabit the ocean. A species of mushroom 
(Agaricus oleartus) grows on the olive tree, which is 
often luminous at night, and resembles the faint, 
lambent flickering light emitted by the scales of 
fish and sea-animals kept in a dark place. Ano- 
malous conditions of various species of Polyporus, 
Hypoxylon, etc., formerly referred to the genus 
Rhizomorpha, from their root-like appearance, 
cover the walls of dark mines with long, black, 
branchy, flat fibres, and give out a remarkably 
vivid phosphorescent light, almost dazzling the eye 
of the spectator. In the coal-mines near Dresden, 
these fungoid bodies are said to cover the roof, 
walls, and pillars, with an interlacing net-work of 
beautiful flickering light, like brilliant gems in 
moonlight, giving the coal-mine the appearance of 
an enchanted palace on a festival night. Mr. 
Gardner, in his interesting travels in Brazil, gives 
the following account of a remarkable phenome- 
non of this nature :—‘One dark night, about the 
beginning of December, while passing along the 
streets of the Villa de Natividade, I observed some 
boys amusing themselves with some luminous ob- 
ject, which I at first supposed to be a kind of large 
fire-fly ; but on making inquiry, I found it to be 
