custs, as a rule, "lie close," sitting tightly folded; their fore- wings (which, with 

 the head, sides, and legs, bear the counter shading and fine patterns) wholly 

 hiding the broad, membraneous hind-wings. These are often brightly and 

 boldly colored, without minute patterns, and when expanded in flight, against 

 sun-variegated backgrounds, they lessen the conspicuousness of the moving 

 insect just as do the bold 'ruptive' markings of many butterflies (and moths). 

 (See Chapter XXVII.) Some of them, again, must under certain conditions 

 act as 'dazzling '-marks, by their sudden display and equally abrupt eclipse. 



Among the Locustidce or true grasshoppers, some of the more terrestrial 

 kinds have much the same general system of protective coloration as have 

 the herbage-haunting Acrydiidce above described. For the most part, how- 

 ever, even these terrestrial ones are less finely patterned, having mere simple 

 'ruptive' patches of green and brown, or kindred colors, and the bright-back- 

 ground picturing above mentioned plays but a small part with them. Many 

 of the more arboreal kinds — of which the well-known " Katydid" (Platy- 

 phyllum concavum) of the eastern United States is a good example, and even 

 some of those that haunt terrestrial herbage, are disguised by leaf mimicry, 

 for the attainment of which the whole body seems to have been modified. 

 The pith of the resemblance, however, lies in the fore-wings, which, when 

 folded, largely or wholly (according to the species) inclose and hide the body, 

 and which, being of a perfect, bright leaf-green, are also marked with a leaf- 

 like midrib and netted side-veins, so that, in profile, the insect closely simu- 

 lates a narrow leaf, or portion of a leaf. But, as in the case of the leaf-edge 

 caterpillars described in the preceding chapter, this mimetic resemblance 

 is largely indebted to obliterative shading. Externally convex, and folded 

 downward over a more or less cylindrical body, these fore-wings are made 

 to look flat by a delicate counter shading, just as we have seen in the case of 

 the caterpillars' bodies. When, as is the way with several species of leaf- 

 mimicking grasshoppers, the fore-wings are comparatively narrow, so that 

 much of the body is exposed, it is obliteratively shaded, to the full, and hence, 

 in the right position relative to the light, it too is 'flattened,' and continues 



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