is included), and the greater number of specimens were of
Lampyris occidentalis. [4] I found that this insect emitted
the most brilliant flashes when irritated: in the intervals,
the abdominal rings were obscured. The flash was almost
co-instantaneous in the two rings, but it was just perceptible
first in the anterior one. The shining matter was fluid and
very adhesive: little spots, where the skin had been torn,
continued bright with a slight scintillation, whilst the
uninjured parts were obscured. When the insect was decapitated
the rings remained uninterruptedly bright, but not so brilliant
as before: local irritation with a needle always increased
the vividness of the light. The rings in one instance retained
their luminous property nearly twenty-four hours after the
death of the insect. From these facts it would appear probable,
that the animal has only the power of concealing or
extinguishing the light for short intervals, and that at other
times the display is involuntary. On the muddy and wet
gravel-walks I found the larvae of this lampyris in great
numbers: they resembled in general form the female of the
English glowworm. These larvae possessed but feeble luminous
powers; very differently from their parents, on the
slightest touch they feigned death and ceased to shine; nor
did irritation excite any fresh display. I kept several of
them alive for some time: their tails are very singular organs,
for they act, by a well-fitted contrivance, as suckers or organs
of attachment, and likewise as reservoirs for saliva, or some
such fluid. I repeatedly fed them on raw meat; and I invariably
observed, that every now and then the extremity
of the tail was applied to the mouth, and a drop of fluid
exuded on the meat, which was then in the act of being consumed.