CHAPTER II 



DEFINITION OF TERMS. ILLUSTRATIONS OF OBLITERATIVE COLORATION 



BEFORE going further we must clearly establish and define the special 

 descriptive terms which are to be used in the course of the book. 

 The term, "the law which underlies protective coloration," as applied to 

 counter shading, was inexact, since "Protective Coloration" of course includes 

 not only concealing-colors based on this newly disclosed principle, but many 

 branches of the entirely different principle of Mimicry, as weU.* A name 

 even more to our present purpose than Protective Coloration, for the com- 

 prehensive meaning, would be one which should include all modifications of 

 the bodies of animals, both those of form and those of color, whose ob- 

 ject seems to be visual deception of any kind. This would make room for 

 offensive as well as defensive mimetic resemblances, etc., and for the many 

 curious cases of protective form modification, most common among the lower 

 orders of animals. But we are to have so little to do with these partially 

 extraneous principles that we need not discard the old and familiar term, Pro- 

 tective Coloration. Interchangeably with it, however, we shall use others some- 

 what more comprehensive, viz.. Disguising Coloration and Disguising Costumes. 



* Throughout our book we shall use the word Mimicry in a wider and perhaps looser sense 

 than that in established use among zoologists, and we herewith offer an apology for this innovation. 

 In order to emphasize tersely the fundamental difference between 'Obliterative Coloration' and 

 both the principles involving imitation of definite objects, which principles have been known re- 

 spectively as Mimicry and Protective Resemblance, we have found it necessary to join the two last 

 mentioned under the general head of Mimicry. Derivatively, the name is nearly as applicable to 

 one as to the other, and the limiting it to the simulation of the colors and forms of animate creatures 

 by those of other animate creatures, in contradistinction to the imitation of inanimate objects, is more 

 or less arbitrary. The two phases are closely related, and for our present purposes must be consid- 

 ered as different branches of one principle, which can only be called Mimicry. 



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