LUMINOSITY OF INSECTS. 
331 
400. There are a few other Insects not included in these 
families, which are reputed to possess luminous powers ; and 
of these the most remarkable are the Fulgorce , or Lantern- 
flies (fig. 175); of which one species inhabits Guiana, whilst 
another is a native of 
China. These are in¬ 
sects of very remark¬ 
able form, having an 
extraordinary proj ection 
upon the head ; and 
this is the part said to 
be luminous. The au¬ 
thority for the assertion, 
however, is doubtful; 
and many Entomologists who have captured the insect, have 
denied the phosphorescent power imputed to it. But it is not 
impossible that the female only may possess it, and that it may 
only be manifested at one part of the year. One of the common 
English species of Centipede , which is found in dark, damp 
places, beneath stones, &c., is slightly luminous; and the 
common Earthworm is also said to be so at the breeding 
season. 
401. Of the particular objects of this provision in the 
Animal economy, little is known, and much has been con¬ 
jectured. It is not requisite to suppose that its purposes are 
always the same; the circumstances of the different tribes 
which possess it being so different. The usual idea of its use 
in Insects,—that it enables the sexes of the nocturnal species 
to seek each other for the perpetuation of the race,—is pro¬ 
bably the correct one. The light is more brilliant at the 
season of the exercise of the reproductive functions, than at 
any other ; and is then exhibited by animals which do not 
manifest it at any other period. Moreover, it is well known 
that the male Glow-worm,*—-which ranges the air, whilst the 
female, being destitute of wings, is confined to the earth,—is 
attracted by any luminous object; as are also the Eire-flies, 
which may be most easily captured by carrying a torch or 
lantern into the open air: so that the poetical language 
in which this phosphorescence is described as “ the lamp of 
love—the pharos—the telegraph of the night, which marks 
by its scintillations, in the silence of the night, the spot 
