Evening star. [volume] (Washington, D.C.) 1854-1972, 1889-02-01
GrasshOppers and Their Harmony of
Color with the Soil.

From the Atlantic Monthly
Go to the seashore and observe the grasshop-
pers among the beach grass. They fly up at
your approach, whiz off a rod or SO, and alight.
Can you see them? They are colored so nearly
like the sands they live upon that detection of
one at rest is almost impossible. On yonder
grassy bluff, stones throw away, you will
find none of them, but other kinds equally, or
almost equally, lost to sight by their harmony
with their surroundings. What chance of life
for either if they suddenly change places?
They would be 80 conspicuous that every pass
ing bird or other insectivorous creature would
sight them. OF course these protective colors
have been gained by slow steps. Every grass
hopper that found its preferred food among
the sands was liable to be eaten. In the long
run Just those would be eaten which were most
easily seen. Onewhichvaried in coloring in never
80 small degree, so as to be less easily seen than
his brother, would live to perpetuate his kind
and his brother come to an untimely end: the
progeny would show the unfortunate variation
and be more likely to be spared to transmit in
increased volume the probability of the happy
coloring. Given, then. a brood of grasshop-
pers that find their preferred food in sandy
spots, and unless other and more powerful
forces act upon them it must result, from their
liability to be eaten by creatures fond of grass
hoppers, that in time they will resemble in col
oring the sand on which they live; it is impos-
sible that they should not. ANY creature not
specially protected by nauseausness. or habit
or special device of some sort must in the
very nature of things, if it is to live at all have
some other protection and that afforded by
color at pattern is by far the most common.
The world is made up of eaters and eaten of
devices to catch and devices to avoid being
caught.
We may apply the same reasoning to two
kind of butterflies subject naturally to the same
class of enemies-that is, living in the same re-
gion and flying at the same time. If one has
the slightest advantage over the other in the
fight for life, by being for instance distasteful
to one class of common enemies SO that these
forbear to attack it after experiment or by in
stinct (the result of ancestral experiments) and
there be among the less favored flock here and
there an individual which. under circum-
stances favoring it. such as distance or shadow,
may more often than its fellows be mis-
taken by the enemy for one of its dis
tasteful neighbors through its possession of a
little more than usual of a certain tint on a part
OF the wing, little larger spot here, or more of
the semblance of a band there-how small soever
this difference may be, it must, by the very
laws of natural selection, be cherished. perpet-
uated. increased, by slow but sure steps Nor
is there any limit to its increase except its abb
solute deception of the enemy. So long as
there is the slightest advantage in variation in
definite position, the struggle for existence
will compel that variation. Knowing what we
now know of the laws of life, mimicry of favored
races might even have been predicted.