Barton County democrat. [volume] (Great Bend, Kan.) 1885-1915, 1893-04-06
COLOR AS A PROTECTION.
The Highland Clans Not the Only Things
Dressed for COncealment.

The Highland CLANS Not the Only Things
Dressed for Concealment.
Where iehen-covered tree stems are
common we find ichen-colored cater
pillars, moths and other insects. A
pretty moth fCleora glabraria), not I'M
common in the New Forest, is white,
busted with black, and its larva, which
feeds upon ichens, is of the same color.
Some years ago while collecting insects
in that locality I found in the same
tufts of ichen a small black and white
spider just as closely resembling the
ichens.
It is supposed that these various color
reSemblances have been brought about
by the need for concealment. A cater
pillar frequenting ichens or bird liv-
ing among leaves would be greatly adj
vantaged by color resemblance to
their several surroundings; hence varia-
tions in the required direction have es-
capped destruction, and there has been
through long ages a gradual perfecting
of the rese mblances. This is the most
generally received explanation. It &C
counts also for the celebration of animals
like the spider, to which have referred,
which do not so much need protection
from their enemies as disguise with
the help of which they can steal upon
their prey.
We must, however, guard against
taking generalities for granted without
a careful examination of the several
cases. Many years ago Messrs. Kirby
and Spence called attention to the re-
semblance between lichen-feeding in
sects and their food: 'sMany of the mot
tied moths, w hich take their station of
II &1,o 50 do ~ &Io
trunks of trees, are with difficulty dis
tinguished from the gray and green
lichens that cover them. Of this kind
are Miselia aprilina and Acronyeta
psi. The caterpillarn of Bryophila
| algae, when it feeds on the yell
low Lich juniperinus, is always
| yellow; but when upon the gray
Lichen saxatilis, it's hue becomes gray.
| This change is probably produced by
! the color of it's food" The last SEN
tence contains most noteworthy sug-
gestion which may help us in explain
ing many similar ca ses of coloration in
d much simpler way than by natural
| selection or natural elimination. 1t is
well known tina the pigments which
are often the eau Sc of the colors in ami
mails and always, except in the case of
| white, of plants, are extremely resist
| ant to chemical action. Some of these
pigments will pass unscathed through
the strongest acids and the most power
full all1alis. 1t is quite conceivable,
then, that they will be equally unaf-
fected by the che mical action of an ami
mails digestive juices.
There is, however, no need at all for
theory upon this point; it has been
shown to be the case in several in
stances. DIR. Eisig found in the Medi-
terranean a species of worm living in
the interior of a sponge. The sponge
was brilliant yellow, the color being
due to particles of a peculiar pigment
deposited in its tissues. The worm was
also yellow, and it might be supposed
that this harmony had been brought
about by the necessity for concealment.
An inquisitive fish poking its nose into
| the interior of the sponge, in search Of
the various small creatures which con-
stantly take up their lodgings in such a
spot, would pass over the ''protectively
colored' worm, and select one that was
obvious on account of its different
colors. 1t was found, however, that
the color of the worm was merely due
to particles of the coloring substance of
| the host, which had passed out of the
! intestine of the worm into its skim
| R1acIxxuoo1,c Mara