The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1867-08-21

the fishes present every variety of gorgeous
color, while the river fish even of the tropics
rarely, If ever, have gay or conspicuous mark
ings. A very curious case of this kind of
adaptation occurs in the sea horses (Hippo-
cdmpus) of Australia, some Of which bear long
fOliaceOus appendages resembling seaweed,
and are of a brilliant red color; and they are
known to live among seaweed of the same hue;
so that when at rest they must be quite invisi-
bic. They are now in the aquarium of the
Geological Society some slender green pipe
fish which fasten themselves to any object at
the bottom by their prehensile tails, and float
about with the current, looking exactly like
some simple cylindrical alge.
II is, however, in the insect world that this
principle of the adaptation of animals to their
environment is most fully and strikingly de-
veloped. In order to understand how general
this is, it is necessary to enter somewhat into
details, as we shall thereby be better able to
appreciate the significance of the still more
remarkable phenomena we shall presently
have to discuss. IL seems to be in proportion
to their sluggish motions or the absence of
other means OF defense that insects possess
the protective cOloring. In the tropics there
are thousands of species of insects which rest
during the day clinging to the bark of dead or
fallen trees; and the greater portion of these
are delicately mottled with grey and brown
tints, which though symmetrically disposed
anu Infinitely NaAlGN5 Jbb bAOAlu ~ OOlAipAJSOiy
the usual colors of the bark, that, at two or
three feet distance, they are quite undistin-
guishable. In some cases, a species is known
to frequent only one species OF tree. This
is the case with the common South Ameri-
can long-horned beetle (OnschOoerus scor-
pio), which, Mr.. Bates informs us, is found
only on a rough-barked tree, called Tapi-
riba, on the Amazon. II is very abundant,
but so exactly does it resemble the bark in
o1o aIsv
to the branches, that until it moves it is abso-
lutely invisible. An allied species CO.. con-
centricuS) is found only at Para on a distinct
species of tree the bark of which it resembles
with equal accuracy. Both these insects are
abundant, and we may fairly conclude that
the protection they derive from this strange
concealment is at least one of the causes that
enables therace to flourish.
Many of the species of Cicindela or tiger
beetle, will illustrate this mode of protection.
Our common Cicindela campestris frequents
grassy banks, and is of beautiful green color,
while c. martina, which is found only on
sandy sea-shores, is of pale bronzy yellow,
so as to be almost invisible. A great number
of the species found by Mr.. Wallace in the
Malay islands are similarly protected. The
beautiful Cicindela gloriosa, of a very deep
velvety green color, was only taken upon wet
messy stones in the bed of mountain stream,
where it was with the greatest difficulty de-
tected. large brown species &C. heroS)
was found chiefly on dead leaves in forest
paths; and one which was never seen, except
on the wet mud of salt marshes, was of glossy
olive so exactly the color of the mud as
only to be distinguished when the sun shone,
by its shadow Where the sandy beach was
coralline and nearly white, he found very
pale Cicindela wherever it was volcanic and
black, dark species of the same genus was
sure to be met with.
There are in the East small beetles of
the family Buprestide which generally rest
on the midIib of leaf; and the naturalist
often hesitates before picking them off, so
closely do they resemble pieces of birds
dung. Kirby and Spence mentien the
small beetle Onthophilus sulcatus as being
like the seed of an umbelliferous plant; and
another small weevil, which is much perse-
cuted by predatory beetles of the genus
Harpalus, is of the exact color of loamy soil,
and was found to be particularly abundant
in loan pits. Mr.. Bates mentions small
beetle (Chlamys pitula) which was undis-
tinguishable by the eye from the dung of
caterpillars, while some of the Cassde, from
their hemispherical forms and pearly gold
color, resemble glittering dew-drops upon the
leaves.
A number of our small brown and specllled
weevils, at the approach of any object,
same time drawing in their legs and an
tenna, which fit so perfectly into cavities for
their reception, that the insect becomes a mere
oval brownish lump, which it is hopeless to
look for among the similarly colored little
stones and earth pellets among which it lies
motionless.
The distribution of color in butterflies and
moths respectively is very instructive from
this point of view. The former have all their
brilliant cOloring on the upper surface of all
four wings, while the under surface is almost
always soberly colored, and often very dark
and obscure. The moths, on the contrary,
have generally their chief color on the hind
wings only, the upper wings being OF dull,
sombre, and often initiative tints, and these
generally conceal the hind wings when the
insects are in repose. This arrangement OF
the colors is therefore eminently protective
because the butterfly always rests with his
wings raised so as to conceal the dangerous
brilliancy of his upper surface. 1t is probable
that If we watched their habits sufficiently
we should find the under surface OF the
wings of butterflies very frequently lmlta-
tive and protective. Mr.. I. w. Wood mas
pointed out that the little orange-tip butter
lily often rests in the evening on the green
and white flower heads of an umbellnerous
plant, and that, when observed in TINS posi-
ton, the beautiful green and white mottInS
OF the under surface completely asslmilates
with the flower heads, and renders the crea-
ture very difficult to be seen. 1t Is pro
bable that the rich dark colorng Oh tne
under side OF our peacock, tortoise-shel anu
red-admlral butterflies answers similar p''r'
| pose.
Two curious South American butterflies
| that always settle on the trunks OF trees
! ((IVupCia Qirce and Cs1Iigona acastal have the