The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1867-08-23
MIMIURY AMONG ANIMALS.
hIimicry and Other Protective Resenl
blances Among Animals.
T(oUc,is3OO I

terra or twO-winged flies, that closely resem-
BILE wasps and bees, and no doubt derive
much benefit from the wholesome dread
which those insects excite. The Midas
dives. and other species of large Brazilian
aies. have dark wings and metallic blue elOn-
gate bodies, resembling the large stinging
Sphepidp of the same country; and a very
large ly of the genus Asilus has black banded
wings and the abdomen tipped with rich
orange, so as exactly to resemble the hne pee
FnpIossa dimidiata, and both are found in the
same parts of South America. We have also
IN onr own country species of Bombylius
yrbicb are almost exactly like bees. In these
casee the end gained by the mimicry is no
Jonbt freedom from attack, but it has
sometimes an altogether different purpose.
There are number of parasitic flies
whose larvae feed upon the Larvae of bees
sneh as the British genus Volucella and
many of the tropical Bombylii, and most
of these are exactly like the particular
species of bee they prey upon, so that
they can enter their nests unsupported to
deposit their eggs. There are also bees that
mimic bees. The cuckoo bees of the genus
Nomada are parasitic on the Andrenidp, and
they resemble either wasps or species of
Andrena; and the parasitic humble-bees of the
genus Apathus almost exactly resemble the
species of humble-bees in whose nests they
are reared. Mr.. Bates informs us that he
found numbers of these "cuckoo"- bees and
flies ON the Amazon, which all wore the livery
of working bees peculiar to the same country.
There is a genus Of small spiders in the
tropics which feed on ants, and they are exactly
like ants themselves, which no doubt gives
them more opportunity of seiZing their prey;
and Mr.. Bates found on the Amazon a species
of Mantis which exactly resembled the white
ants which it had fed upen, as well as several
species of crickets (Scaphura), which resem-
bled in a wonderful manner different sand
wasps of large size, which are constantly on
the search for erickets to provision their nests
with
o. Perhaps the most extraordinary of all is the
large caterpillar mentioned by Mr.. Bates,
which startled him by its close resemblance to
small snake. The first three segments
behind the head we've dilatable at the will of
the insect and had on each side large black
pupillated spot, which resembled the eye of
the reptile. Moreover, it resembled poison
GUS viper, not harmless species of snake, as
was proved by the imitation of keeled scales
on the crown produced by the recumbent feet,
as the caterpillar threw itself backward
The attitudes of many of the tropical spiders
are most extraordinary and deceptive, but
little attention has been paid to them. They
often mimic other insects, and some, Mr..
Bates assures us, are exactly like flower buds,
and take their station in the axis of leaves,
where they remain motionless waiting for their
prey.
Having thus shown how varied and extra
ordinary are the modes in which mimicry
occurs among insects, we have now to inquire
if anything of the same kind is to be observed
among vertebrated animals. When we con-
slider all the conditions necessary to produce a
good deceptive imitation we shall see at once
that such can very rarely occur in the higher
animals, since they possess none of those facili-
ties for the almost infinite notifications of ex-
ternal form which exist in the very nature OF
insect organization. The outer covering OF
insects being more or less solid and horny,
they are capable of almost any amount OF
change of form and appearance without any
essential modification internally. In many
groups, the wings give much of the character,
and these organs may be much modified both
In form and color without interfering with
their special functions. Again the number
of species of insects is so great and there is
such diversity of form and proportion in every
group, that the chances of an accidental
approximation in size, form, and color, of one
insect to another of a different group, are very
cOnsderable and it is these chance approx
nations that furnish the basis of mimicry, to
be continually advanced and perfected by the
survival of those varieties only which tend in
the right direction.
In the Vertebrate, on the contrary, the
skeleton being internal, the external form de-
pends almost.entirely on the proportions and
arrangement that skeleton, which again is
strictly adapted to the functions necessary for
the well-being of the animal. The form can
not therefore be rapidly modified by variation,
and the thin and flexible integument will not
admit of the development of such strange pro-
tuberances as occur continually in insects.
The number of species of each group in the
same country is also comparatively small and
thus the chances of that first accidental resem-
blance which is necessary for natural selection
to work upon are much diminished. We can
hardly see the possibility of mimcry by which
the elk could escape from the wolf, or the buff
falO from the tiger. There is, however, in one
group OF Vertebrate such a general similarity
of form, that very slight modification, if ac-
companied by identity of color, would pro-
duce the necessary amount of resemblance;
and at the same time there exist number
of species which it would be advantageous for
others to resemble, since they are armed with
the most fatal weapons of offense. We ac-
cordingly find that reptiles furnish US with a
very remarkable and instructive case of true
mimicry.
There are in tropical America a number of
Venomous snakes of the genus Flaps, which
are ornamented with brilliant colors disposed
IN peculiar manner. The ground color is
generally bright red, on which are black hands
OF various widths, and sometimes divided into
two or three by yellow rings Now. in the same
country are found several genera of harmless
snakes, having no affinity whatever With the
above, but colored exactly the same. For e~-
ample, the poisonous Flaps fulvius often occ,,rs
in Guatemala with simple black bands ON q
coral red-ground and in the same countrv e
found the harmless snalra pl;ooo,,.1 ~ i'