But — especially in the moths' case — these are rare exceptions to a widely com- 

 prehensive rule. On the other hand, moths' regular habit of flat-folding is sub- 

 ject to several notable modifications. Many small kinds fold up almost cylin- 

 drically, 'furling' their wings around their bodies, and when thus folded they 

 sit fitted close to slender twigs or grass blades — ^like certain tree toads. Such 

 moths often bear a mimetic likeness to bits of stick or grass, or even to bird- 

 droppings, but often also they are patterned and colored ohliteratively. Again, 

 the triangularly folded wings of many tree-bark moths, etc., slope downward 

 steeply from the top ridge of the thick body, so that the moths' picture-patterned 

 surface is by no means actually flat. 



Let us glance at a few more special types of pattern characteristic of ' close- 

 lying' moths in general. Among all the various perches which these moths 

 frequent, few or none are so abundantly favored by them as tree trunks. 

 Accordingly, the tree-bark pattern, in various forms, is probably the most 

 prevalent of all picture-patterns on moths' wings. The two extremes of this 

 form of marking are: first, a pattern of the finest grizzling and speckling, 

 which counterfeits with exquisite minuteness the look of finely broken bark, 

 flecked with tiny lichens, etc. (see Figs. 136-138), and second, a pattern which 

 depicts the larger details of rough or ragged bark, rendering, by contrasts of 

 dark and light, by sharp lines and soft blendirigs, the look of sharp-edged 

 substances casting shadows on their background. Each of these types, as is 

 almost needless to say, is subject to multitudinous variations, and the two 

 extremes are combined and intergraded to the last degree. A beautiful 

 example of the larger-detail type, pure and simple, is the sphinx moth shown 

 in Fig. 139. (See also Fig. 140.) But there are some still further specialized 

 cases of bark-picturing among moths, sometimes accompanied by highly 

 specialized habits. A large gray noctuid moth which I saw in the woods of 

 Trinidad, B. W. I., always perched sideways on the trunks of trees and bushes. 

 That is, it would sit with flatly-applied wings trending up and down the trunk 

 instead of across it. Its flight was swift and straightforward, but in alighting 

 it always whipped itself around into the sidewise posture. The reason, or at 



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