II 
PHOSPHORESCENT INSECTS 
3 1 
lutely perpendicular. Various cicadae and crickets, at the same 
time, keep up a ceaseless shrill cry, but which, softened by the 
distance, is not unpleasant. Every evening after dark this great 
concert commenced ; and often have I sat listening to it, until 
my attention has been drawn away by some curious passing insect. 
At these times the fireflies are seen flitting about from 
hedge to hedge. On a dark night the light can be seen at 
about two hundred paces distant. It is remarkable that in all the 
different kinds of glowworms, shining elaters, and various marine 
animals (such as the Crustacea, medusae, nereidse, a coralline of 
the genus Clytia, and Pyrosoma), which I have observed, the 
light has been of a well-marked green colour. All the fireflies, 
which I caught here, belonged to the Lampyridae (in which 
family the English glowworm is included), and the greater num¬ 
ber of specimens were of Lampyris occidentals 1 I found that 
this insect emitted the most brilliant flashes when irritated : 
in the intervals, the abdominal rings were obscured. The 
flash was almost coinstantaneous 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 prob¬ 
able, 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 irrita¬ 
tion 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, 
1 I am greatly indebted to Mr. Waterhouse for his kindness in naming for me 
this and many other insects, and in giving me much valuable assistance. 
