Year: 1873

MUSCULAR STRENGTH OF INSECTS.


IT is an interesting study to compare the
motive power of birds and insects, and
recent experiments prove that they are su-
perior in this respect to oquadrupeds, espec-
tally when the possibility of aerial naviga-
ton is taken into account. In few min
utes the condor will soar many miles in
height; the swallow is not weary of de-
scribing its rapid and graceful curves for
fifteen hours at a time. 1t has been
calculated that the eagle, with its rapid
flight, produces an effort sufficient to raise
and bear up its own weight equal to
tWenty-six horse power.


Insect organization is as full Of wonders
as that Of the bird. The energy which
lives in these curious little creatures may
well excite the wonder of an observer III
YOU compare their loads with the size OF
ants ''it must be allowed thatno other an
imal is endowed with such immense
strength in propOrtion.' Sir Walter
Scott suggests the same idea When a
beetle is placed under a candlestick, it
will move it in its efforts to escape; which
is relatively the same thing as prisoner
in Newgate shaking the building with his
back Linn@us remarks that an elephant
having the force of a hOrn-beetle would be
able to move mountain.


Mr.. Felix Plateau, young Belgian
naturalist, and a son of the celebrated
physician, has lately tried some very deli
cate experiments to measure the muscular
strength of insects, as others have done
with man and the horse. The strength OF
the last two is estimated by the aid OF
machine called the dynamometer, where
the tension of spring is counterbalanced
by an effort exercised for a very short
time man, it is found, has power of
traction equal to five-siXths of his weight,
q horse only the half or tWO-thlrds OF his
weight; but this is very small in cOmpar
ison with the strength of insects, many OF
which can draw forty times that amount.


The way in which M. Plateau has meas
ured these powers is ingenious. He har-
messed the insect by horizontal
thread which was passed over light,
movable pulley; to this was attach
ed a balance loaded with a few grains
of sand. To prevent the insect turn
inc aside, he made it walk between two
bars of glass on board covered with mus
lin, so as to afford rough surface; ex-
citing it forward, he gradually poured
fresh sand into the balance until it refused
to advance farther; the sand ana the In
sect were then weighed, and the eXperl-
ment was repeated three times, in order to
arrive at a correct conclusion as to the
greatest effort that each could make. Inc
fables which give the result of these trials
seem clearly to demonstrate that in the
same group of insects the 1ightest and
smallest possess the greatest strength; so
that the relative force is in inverse ratio
to the weight. The law applies also to
the experiments in flying and pushing, as
well as to drawing.


This law, assuredly very curious ana
interesting in the economy OF nature, mas
been confirmed by trying dozen lnd1vld-
uals of various species in order to OBTAIN
results more approaching to the truth.
These have been fully successful In con-
irminr previous eXperience-for exam
ME. the drone is four times the weight of
the bee, vet it can only drag a weight fiji
teen times greater than its own;
whilst the bee easily draws twen-
ty-three or twenty-four times its own
bulk In flying, it can raise weight very
little inferior to its own; whilst the drone
car only transport in this manner hall Its
own weight The law in question appears
also to apply not only to the species
which belong to the same chronological





the entire class of insects. 1t is true that
if the species examined are arranged by
the increasing order of their weight, the
corresponding relations which express
their relative force are not always exactly
progressive. There are exceptions, which
may be explained by the difference of
structure The law holds good if they
are divided into three groups, comprising,
respectively, the lightest insects, those OF
a middle size, and the heaviest. In this
way the relative force is represented tor
the first group by twenty-six; for the sec
ond, by nineteen; for the last, by nine.
This relates only to the power of traction;
if that in flying be taken into considera-
ton, the lightest can far surpass the heavi-
est-the first being equal to one and one
third; the last is but one-half The strong
est insects appear to be those so familiar
to the naturalist, which live on lilies and
roses. such as the Cri0cereS and Irichies
These little beings can draw weight
abotit forty times superior to their own,
and one. an athlete of the tribe, drew
sixty seven times its own weight A small
beetle of the tribe dn0naa!e has executed
the same feat.


Another more remarkable fact is related
of a horn-beetle, which held between It's
mandibles, alternately raising and lower
ing its head and breast, rod of thirty
centimetres long, weighing four hundred
grammes; its own weight was but two
grammes AT the side of this insectwhat
are the acrobats who can carry table be-
tween their teeth! Such examples show
to what an extent insects are superior to
the larger animals in the strength of their
muscles. Dry and nervous, they can, in
nronortion to themselves, move noun
tains In addition to this, they are in
renious; when an obstacle does not yield
TO them, they know how to turn 1t aside.
One day, in a garden, small wasp was
irving to raise caterpillar, which 1t had
lust killed The caterpillar was at least
five or six times heavier than It's conquer
or, which could not gain its end. ok
times successfully, y,wearied fthe war; ana