PACKARD] INSECTS AS MIMICS. 259 



struggle for life in a -vvorlcl existing in a state of constant 

 incquiiihriuni. 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 mimicr}' 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 mi7nicking 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. Tiie 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, arc 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 duskytfor much the same reason that the 

 grass is green, the sky seems blue, or the rocks are gray. 

 These harmonics 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 tliose 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 ])lants had 

 multiplied to an}' 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 nothiu": to jrrind. 



