Packard.] 
INSECTS AS MIMICS. 
259 
struggle for life in a world existing in a state of constant 
inequilibrium. It is the changes in the conditions of life, 
the revolutions in the physical surroundings of organisms, 
which have induced the transformation of one species into 
another, while protective mimicry has often acted as a con¬ 
servative agency in preserving the species. Both sets of 
causes have, then, been factors in the origination of animals 
and plants as we see them, and Darwinism is perhaps as 
essential as Lamarckianism in explaining the present condi¬ 
tions of life on the globe. 
But to come at once to the subject of protective mimicry, 
we will study in the first place :— 
Insects mimicking other natural objects. — The examples 
under this head illustrate some of those harmonies in nature 
which the distinguished Bernard de Saint Pierre saw so 
clearly. The adaptive coloration of animals, the harmony 
in tint and form with the trees on which they live, or the rocks 
among or under which they hide, the sand over which they 
run, are a part of the general harmony in nature. A desert 
animal is of a sandy complexion, a silk-worm moth is brown, 
a grasshopper is dusky for much the same reason that the 
gfass is green, the sky seems blue, or the rocks are gray. 
These harmonies in form, in color, are as striking in the world 
as a whole, as in isolated portions of it, or isolated species of 
the animals or plants growing on its surface. These harmo¬ 
nies extend to other worlds and systems of worlds, and are 
cosmical in their nature. So the causes that lead to the 
origination of life, of a new species, are perhaps of a piece 
with those resulting in the origin of a planet. We must 
remember that life at first resulted in all probability through 
the action of cosmical laws. Before animals and plants had 
multiplied to any extent, where was the material for the 
laws of natural selection to act upon ? There was once a 
time when some of the mills of the gods failed to run for 
the reason that there was nothing to grind. 
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