are achieved ; on no other basis could they be achieved, or would they greatly 

 avail the animal. (See, however, the definition of Mimicry in Chapter II.) 



The reader who has assimilated what we have said thus far, is now in a 

 position to perceive the fallacy of the statement, prevalent in former years, 

 and still made by certain writers, that a protectively colored animal of the 

 type described above escapes detection because, being of a dull-brown color 

 like the ground and the bushes, it looks when it sits motionless like a clod or a 

 stump — or some such inanimate thing. For clods and stumps are solid 

 objects of a uniform tint, and manifest to the eye, by the laws of light-and- 

 shade, not only their solidity, but all their smaller modelings. They are not 

 inconspicuous, except in so far as their great abundance makes the eye in- 

 attentive to individual ones. The protectively colored animal, on the other 

 hand, is, as it were, obliterated by his counter-gradation of shades, and in 

 the cases where he escapes notice, it is by virtue, not of the eye's perceiving 

 his solid form, and taking it for that of an inanimate object, but of its failure 

 to recognize it as a solid object of any kind, seeming, if it rests on it at all, 

 to see through it to what is beyond. For the animal looks at most like a flat 

 plane interposed between its background and the observer; and since actual 

 flat foreground-planes of this kind at right angles to the earth do not com- 

 monly exist in the woods and fields, the eye usually interprets the animal's 

 surface as part of the scene, ground-plane or wood mass, simple or com- 

 pound, which lies beyond it. If these animals were merely brown or gray 

 like clods and stumps, they would not be concealed, because their structural 

 forms are too distinct, and the eyes of enemies are keen to detect their charac- 

 teristic 'modeling' and outlines. On the other hand, a perfect shade- 

 gradation, even of some rankly brilliant color, would go far toward concealing 

 an animal, for he would still have no appearance of solidity; and any varied 

 landscape, especially a sunlit one, even in the dingy temperate zone, is full 

 of patches of brilliant color, as all artists know.* 



* A large expanse of any strong color, as the green of the foliage, begets in its interstices and on 

 its borders an appearance of its "complementary." It is partly for this reason, as an American 



19 



