To all wild creatures fire is an unknown and hated thing, although it is
often so fascinating to them that they will stand transfixed gazing at its
mysterious light, while a hunter, unnoticed, creeps up behind and shoots
them.
In the depth of the sea, where the sun is powerless to send a single ray
of light and warmth, there live many strange beings, fish and worms,
which, by means of phosphorescent spots and patches, may light their own
way. Of these strange sea folk we know nothing except from the fragments
which are brought to the surface by the dredge; but over our fields and
hedges, throughout the summer nights, we may see and study most
interesting examples of creatures which produce their own light. Heedless
of whether the moon shines brightly, or whether an overcast sky cloaks the
blackest of nights, the fireflies blaze their sinuous path through life.
These little yellow and black beetles, which illumine our way like a cloud
of tiny meteors, have indeed a wonderful power, for the light which they
produce within their own bodies is a cold glow, totally different from any
fire of human agency.
In some species there seems to be a most romantic reason for their
brilliance. Down among the grass blades are lowly, wingless creatures--the
female fireflies, which, as twilight falls, leave their earthen burrows in
the turf and, crawling slowly to the summit of some plant, they display
the tiny lanterns which Nature has kindled within their bodies.
Far overhead shoot the strong-winged males, searching for their minute
insect food, weaving glowing lines over all the shadowy landscape, and
apparently heedless of all beneath them. Yet when the dim little beacon,
hung out with the hopefulness of instinct upon the grass blade, is seen,
all else is forgotten and the beetle descends to pay court to the poor,
worm-like creature, so unlike him in appearance, but whose little
illumination is her badge of nobility. The gallant suitor is as devoted as
if the object of his affection were clad in all the gay colours of a
butterfly; and he is fortunate if, when he has reached the signal among
the grasses, he does not find a half-dozen firefly rivals before him.
When insects seek their mates by day, their characteristic colours or
forms may be confused with surrounding objects; or those which by night
are able in that marvellous way to follow the faintest scent up wind may
have difficulties when cross currents of air are encountered; but the
female firefly, waiting patiently upon her lowly leaf, has unequalled
opportunity for winning her mate, for there is nothing to compare with or
eclipse her flame. Except--I wonder if ever a firefly has hastened
downward toward the strange glow which we sometimes see in the heart of
decayed wood,--mistaking a patch of fox-fire for the love-light of which
he was in search!
In other species, including the common one about our homes, the lady
lightning-bug is more fortunate in possessing wings and is able to fly
abroad like her mate.
Although this phosphorescence has been microscopically examined, it is but
slightly understood. We know, however, that it is a wonderful process of
combustion,--by which a bright light is produced without heat, smoke, or
indeed fuel, except that provided by the life processes in the tiny body
of the insect.
So shines a good deed in a naughty world.
Shakespeare.