water, and sends forth a pleasing chirp. When several were
together they sung in harmony on different notes. Various
cicadæ and crickets, at the same time, kept up a ceaseless
shrill cry, but which, softened by the distance, was 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. All that I caught belonged to the family of
Lampyridæ, or glowworms, and the greater number were
Lampijris occideutaiis. 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 first just perceptible
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. AVhen 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 larvæ of this lampyris in great numbers
: they resembled in general form the female of the English
g low o rm . These larvæ possessed but feeble luminous
powers ; very differently from their parents, on the slightest
touch they feigM^
tion excite any fresh display. I kept several of them alive for
* O n a d a rk n ig h t th e lig h t c o u ld b e s e e n a t a b o u t tw o h u n d r e d p a c es
d is ta n t I t is rem a rk a b le t h a t in a ll th e g lowworms, sh in in g e la te rs , a n d
v a rio u s' m a r in e an im a ls , w h ic h I h a v e o b s e rv e d ( su c h a s th e Crustacea,
m ed u sa i, n e re idæ , a c o ra llin e o f th e g e n u s C ly tia , a n d P y ro som a ) , th e lig h t
h a s b e e n o f a w e ll-m a rk e d g re e n co lo u r.
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. The tail, notwithstanding
so much practice, does not seem to be able to find
its way to the mouth; at least the neck was always touched
first, and apparently as a guide.
When we were at Bahia, an elater {Pyrophorus lummosiis,
Illig.) seemed the most common luminous insect. The
light in this case was also rendered more brilliant by irritation.
I amused myself one day by observing the springing
powers of this insect, which have not,* as it appears to me,
been properly described. The elater, when placed on its
back and preparing to spring, moved its head and thorax
backwards, so that the pectoral spine was drawn out, and
rested on the edge of its sheath. The same baokw’ard movement
being continued, the spine, by the full action of the
muscles, was bent like a spring; and the insect at this
moment rested on the extremity of its head and elytra.
The effort being suddenly relaxed, the head and thorax flew
up, and, in consequence, the base of the elytra struck the
supporting surface with such force, that the insect by the
reaction was jerked upwards to the height of one or two
inches. The projecting points of the thorax, and the sheath
of the spine, served to steady the whole body during the
spring. In the descriptions which I have read, sufficient
stress does not appear to have been laid on the elasticity of
the spine: so sudden a spring could not be the result of
simple muscular contraction, without the aid of some
mechanical contrivance.
On several occasions I enjoyed some short but most
pleasant excursions in the neighbouring country. One day
* K irb y ’s E n tom o lo g y , vol. ii., ¡i, 317.
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