The Iola register. [volume] (Iola, Allen County, Kansas) 1875-1902, 1893-04-07
COLOR AS A PROTECTION.
The Highland Clans Not the Only Thing
Dressed for Concealment.

DTesstu SOnc~1AAches
Where lichen-covered tree stems are
common we find ichen-colored cater
pillars. moths and other insects. A
pretty moth (Cleora glabraria), not I'M
common in the New Forest, is white,
busted with black, and its larva, which
feeds upon lichens, is of the same color.
Some wears ago while collecting insects
in that locality I found in the same
tufts of lichen a small black and white
spider just as closely resembling the
hchens.
It is supposed that these various color
resemblances have been brought about
by the need for concealment. A cater
pillar frequenting lichens or a bird liv-
ing among leaves would be greatly ad-
vantaged by a color resemblance to
their several surroundings; hence varia-
lions in the required direction have es-
capped destruction, and there has been
through long ages gradual perfecting
of the resemblances. This is the most
generally received explanation. 1t &C
counts also for the coloration 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
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: ''Many of the mot
! tied moths, w hich take their station of
| diurnal repose on the north side of the
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 caterpillar 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 its food" The last SEN
tence contains a most noteworthy sug-
gestion which may help us in explain
ing many similar ca ses of coloration in
a 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 alkalis. 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 DR.. Eisig found in the Medi-
terranean 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 polling 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
| coloredr worm. and select one that was
obvious on account of its different
colors. 1t was found, however. thai
khe color of the worm was merely due
to particles of the coloring substance o.
the host, which had passed out of the
intestine of the worm into its skim
| Rlacl,yOod,S MaUazine