few persons realize that a vast number of insects and
lower organisms are endowed with the superhuman ability of producing
light by physiological processes. Apparently the chief function of these
lighting-plants within the living bodies is not to provide light in the
sense that the human being uses it predominantly. That is, these
wonderful light-sources seem to be utilized more for signaling, for
luring prey, and for protection than for strictly illuminating-purposes.
Much study has been given to the production of light by animals, because
the secrets will be extremely valuable to mankind. As one floats over
tide-water on a balmy evening after dark and watches the pulsating spots
of phosphorescent light emitted by the lowly jellyfishes, his
imaginative mood formulates the question, "Why are these lowly organisms
endowed with such a wonderful ability?"

Despite his highly developed mind and body and his boasted superiority,
man must go forth and learn the secrets of light-production before he
may emancipate himself from darkness. If man could emit light in
relative proportion to his size as compared with the firefly, he would
need no other torch in the coal-mine. How independent he would be in
extreme darkness where his adapted eyes need only a feeble
light-source! Primitive man, desiring a light-source and having no means
of making fire, imprisoned the glowing insects in a perforated gourd or
receptacle of clay, and thus invented the first lantern perhaps before
he knew how to make fire. The fireflies of the West Indies emit a
continuous glow of considerable luminous intensity and the natives have
used these imprisoned insects as light-sources. Thus mankind has
exhibited his superiority by adapting the facilities at hand to the
growing requirements which his independent nature continuously
nourished. His insistent demand for independence in turn has nourished
his desire to learn nature's secrets and this desire has increased in
intensity throughout the ages.

The act of imprisoning a glowing insect was in itself no greater stride
along the highway of progress than the act of picking a tasty fruit from
its tree. However, the crude lantern perhaps directed his primitive mind
to the possibilities of artificial light. The flaming fagot from the
fire was the ancestor of the oil-lamp, the candle, the lantern, and the
electric flash-light. It is a matter of conjecture how much time elapsed
before his feeble intellect became