of the disguising coloration of the butterflies (and moths) inhabiting say a 

 few square miles of Brazilian forest, he would doubtless be discovering new 

 wonders even of essential principle on the last day of his hunting. 



Our own knowledge of the subject is of the slenderest and most frag- 

 mentary sort; nevertheless we can open several vistas into quite untrodden 

 fields of exquisite truth. Some few of our readers are already familiar with 

 my father's paper on " Protective Coloration in its Relation to Mimicry, 

 Common Warning Colors, and Sexual Selection," * wherein most of his 

 discoveries concerning butterfly coloration are clearly outlined. The present 

 chapter contains but little which was not at least foreshadowed in the above- 

 named paper, or in an article by me published in the Century Magazine 

 for June, 1908, and the reader must take it as a recapitulation and enlarge- 

 ment of these earlier essays. 



In the first place, the obliteration of butterflies is a very different problem 

 from that of vertebrates, or even large-bodied insects. Obliterative shading 

 is but scantily called into play, for their principal members, their wings, are 

 flat and paper-thin. Their slim, cylindrical bodies are almost always counter- 

 shaded, to perfection, but this is, comparatively, a small detail of their dis- 

 guisement. Their great flat wings, with their characteristic outlines, have 

 to be disguised by other means. In the case of birds and beasts, etc., Nature 

 has to use artifice and deception to make them into 'canvases' for back- 

 ground pictures; but butterflies' wings are actually flat planes, all ready for 

 the pictures. These Nature gives them, to the highest imaginable degree, 

 ranging through a scale of variations marvelous in its immensity, yet fur- 

 nishing each species with a costume well fitted to its own peculiar mode of 

 life (although, as ' already explained, the perfection of the fitness may be 

 no longer discernible, since it is often marred by rapid, man-wrought changes 

 in a butterfly's natural environment). 



This great agglomeration of differing butterfly types (as far as it is known 



* Published in the "Transactions of the Entomological Society of London" for December 

 24, 1903. 



213 



