are almost always at least a few inches distant from them, and subject both 

 to much variety and complexity of detail and to a good deal of refinement and 

 distortion by perspective. Some of them, indeed, wear rich, varied ground- 

 scenery pictures, scarcely rivaled by those of the most finely patterned forest 

 birds. Others are colored very simply, with either many very faint and 

 delicate or few and bold obliterative markings. 



Passing now to the class of aerial butterflies, i. e., those which spend a 

 much greater proportion of their time in flight, and do not characteristically 

 "sit close" on perches, we find, of course, new general schemes of coloration. 

 But as I said before, the two classes are by no means clearly separate, and 

 hence their distinctive color schemes are subject to interminglement, of many 

 forms. In the first place, most of the 'sedentary' wing-folding butterflies, 

 such as we have been considering, are 'aerially colored,' so to speak, on the 

 upper side. That is, their upper sides bear either such colors and patterns 

 as decrease to the utmost possible degree their inevitable conspicuousness in 

 flight, such as tend to obliterate the wings of the perching insect when they 

 chance to be expanded, or such as 1 dazzle ' in the way mentioned in Chapter 

 XXVI, p. 199, and of which the reader is soon to hear more. (' Dazzling '- 

 colors of this kind, indeed, are confined, in their full development, to close- 

 folding 'sedentary' butterflies, and, contrariwise, there are few such butter- 

 flies whose upper-side colors do not On occasions perform this ' dazzling '- 

 function, however largely obliterative may be their general use.) 



There are butterflies which alight very often, but do not stay long in one 

 place, and either keep their wings outspread, or are continually closing and 

 opening them. These, intermediate between the sedentary and the aerial 

 types, share the color schemes of both, — perhaps inclining, in costumes as in 

 actions, to the aerial. Their trick of wing- waving, however, is common, in 

 more or less pronounced form, to most butterflies, — some of the tight-folding 

 ' sedentaries ' alone being nearly exempt from it. (In conjunction with the 

 less minutely detailed patterns of many of the species that practice this trick, 

 it would seem to be a general measure for 'assimilation' with their surround- 



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