Evening star., 1901-06-29
IMPOsTORs AMONG ANIMALS.
Moths and Other Insects That Initiate
Their Environment.

William Morton Wheeler In the Century.
The Shakespearean conception of the hu-
man world stage may be expanded to
include the animal world as well. Like
ourselves, animals enter on the struggle
for existence with a modicum of equip
ment in figure, complexion, voice and de-
meanor, and with the assignment of
definite role to play in the melodrama of
life Hence We are not surprised to find
that many of our four, six and eight-footed
competitors have, fguratively speaking. at
tanned to some proficiency in the art of
imposition while endeavoring to gain
fOCthold in the worid-i e., the opportunity
of feeding, mating and leaving offspring TO
repeat the same performance continuously.
1t must have been some such reflections
as this which led Henry Drummond to
mark that Carlyle in his blackest visions
of 'shamS and humbugS' among human
kind never saw anything so finished in
hypocrisy the naturalist now finds in
every tropical forest. There are to be seen
creatures, not singly, but in tens of thou
sands, whose every appearance, down to
the minutest spot and wrinkle, is an af-
front to truth, whose every attitude is
pose for purpose, and whose whole life
Is sustained lie. Before these master
pieces of deception the most ingenious of
human impositions are vulgar and trans
parent. Fraud is not only the great rule
of life in a tropical forest, but the one con-
ditiou of it,
Drummond's statements are perhaps a
little misleading without some qualification,
for animals are not impostors in the ordi-
nary sense of the term, since they are, of
course, perfectly unaware of appearing un-
der a deceptive disguise. Moreover. what
Is true Of animal life in the tropic is also,
in great measure true of animal life in
other regions of the globe.
In the development of deceptive disgulses
-disguises which affect the form. attitude
and color, but largely the color, of animals
nature appears to have proceeded along
two different paths, one Of which is direct
and relatively easy. the other circuitous
and much more difficult. The easy path,
which may be considered first, is that of
protective resemblance pure and simple
l. e. an approach in the animals form,
color and attitude to some object in the
surroundings. Such an approximation can
hardly fail to be of the greatest advantage.
since the animal thereby merges SO COM
pletely with its environment as to pass un-
observed by it's enemies or by it's prey.
This alternative has led in two directions,
to defensive and an aggressive form of
resemblance.
Every sportsman has been deceived by
the close resemblance of birds and other
animals to the soil and vegetation. 1t
would be easy. moreover, to show that
many reptiles, frogs and fishes and very
many of the lower animals exhibit similar
adaptations. It is also well known that
some of these creatures. like the chame-
lecnS, many tree frogs, cuttlefshes and
shrinps can actually change their colors
to make them harmonize with the exact
tints of the vegetation or soil on which
they are living. But no animal can COM
pare with the insects and spiders in the de-
tailed perfection of their protective dis
guises, or in the frequency of adopting
this method of eluding enemies or of
stealthily approaching prey. This is true
notwithstanding the fact that active color
changes like those of the chameleon are
scarcely known to occur among insects.
Many of the most striking examples of
protective resemblance among insect are
the result of the very intimate association
of these animals with the fora of our plan
ct Especially is this true Of insects which
live exposed on the vegetation. There is
really no portion of the plant excepting its
roots and fruits which is not copied by
some insect often with the most astonish-
ing faithfulness to details. Hosts of moths
copy the rough lichen-mottled bark of
trees; the walking sticks and looping cater
pillars copy the twigs; the green leaves are
initiated by the katydids and the marvel
Gus leaf-insects Phyllium) of the East In
dies, while the dead leaves are portrayed
by many moths and butterflies. form of
resemblance eliminating In the famous
Kallima BUTTERFLIES Of aouthern Asia. 6trik- 4