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I
I want to talk about Japanese fireflies, but not entomologically.
If you are interested, as you ought to be, in the scientific side
of the subject, you should seek enlightenment from a Japanese
professor of biology, now lecturing at the Imperial University of
Tōkyō. He signs himself "Mr. S. Watasé" (the "S" standing for the
personal name Shozaburo); and he has been a teacher as well as a
student of science in America, where a number of his lectures have
been published,[1]--lectures upon animal phosphorescence, animal
electricity, the light-producing organs of insects and fishes, and
other wonderful topics of biology. He can tell you all that is
known concerning the morphology of fireflies, the physiology of
fireflies, the photometry of fireflies, the chemistry of their
luminous substance, the spectroscopic analysis of their light, and the
significance of that light in terms of ether-vibration. By experiment
he can show you that, under normal conditions of temperature and
environment, the number of light-pulsations produced by one species
of Japanese firefly averages twenty-six per minute; and that the
rate suddenly rises to sixty-three per minute, if the insect be
frightened by seizure. Also he can prove to you that another and
smaller kind of firefly, when taken in the hand, will increase the
number of its light-pulsings to upward of two hundred per minute.
He suggests that the light may be of some protective value to the
insect,--like the "warning colours" of sundry nauseous caterpillars
and butterflies,--because the firefly has a very bitter taste, and
birds appear to find it unpalatable. (Frogs, he has observed, do not
mind the bad taste: they fill their cold bellies with fireflies till
the light shines through them, much as the light of a candle-flame
will glow through a porcelain jar.) But whether of protective value or
not, the tiny dynamo would seem to be used in a variety of ways,--as
a phototelegraph, for example. As other insects converse by sound or
by touch, the firefly utters its emotion in luminous pulsings: its
speech is a language of light.... I am only giving you some hints about
the character of the professor's lectures, which are never merely
technical. And for the best part of this non-scientific essay of
mine,--especially that concerning the capture and the sale of fireflies
in Japan,--I am indebted to some delightful lectures which he delivered
last year to Japanese audiences in Tōkyō.