290 FIRST FORMS OF VEGETATION. 
in sheets of lambent flame, presenting a most ex- 
traordinary appearance, through which I had the 
greatest difficulty in persuading my horse to pass. 
This, the grandest display of phosphorescence I 
have ever seen on land, was produced by countless 
fragments of rotten wood, threaded with the white 
spawn of fungi, that had been swept down upon 
the road from the wood above by the heavy rains. 
Superstition and ignorance have magnified this 
simple appearance of nature into a supernatural 
manifestation ; the zgvzs fatuzs occasionally seen in 
damp old woods, and regarded by the credulous as 
a sign of approaching death and an omen of evil, 
being often nothing else than the flickering phos- 
phorescence of fungi in a state of decay. It may 
be remarked in connexion with this luminous pro- 
perty, that many fungi are capable of generating 
considerable heat. Dutrochet ascertained that the 
highest temperature produced by any plant, with 
the exception of the curious cuckoo-pint of our 
woods, was generated by a species of toadstool 
called Boletus e@neus. Such being the curious pro- 
perties exhibited by these plants, it is not surpris- 
ing that at one period they should have been re- 
garded as animal productions, formed by insects 
for their habitations, somewhat like the coral- 
structures of zoophytes and sponges. Though 
this view has long been discarded, yet fungi, as 
