And to
believe even this we should first have to assume that bats and
goatsuckers are differently constituted from all other creatures; for in
other animals--insects, birds, and mammalians--the appearance of fire by
night seems to confuse and frighten, but it certainly cannot be said to
_warn,_ in the sense in which that word is used when we speak of the
brilliant colours of some butterflies, or even of the gestures of some
venomous snakes, and of the sounds they emit.
Thus we can see that, while the old theory of Kirby and Spence had some
facts to support it, the one now in vogue is purely fanciful. Until some
better suggestion is made, it would perhaps be as well to consider the
luminous organ as having "no very close and direct relation to present
habits of life." About their present habits, however, especially their
crepuscular habits, there is yet much to learn. One thing I have
observed in them has always seemed very strange to me. Occasionally an
individual insect is seen shining with a very large and steady light, or
with a light which very gradually decreases and increases in power, and
at such times it is less active than at others, remaining for long
intervals motionless on the leaves, or moving with a very slow flight.
In South America a firefly displaying this abnormal splendour is said to
be dying, and it is easy to imagine how such a notion originated. The
belief is, however, erroneous, for sometimes, on very rare occasions,
all the insects in one place are simultaneously affected in the same
way, and at such times they mass themselves together in myriads, as if
for migration, or for some other great purpose.
Pages:
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178