speak, with all manner of rents, and vistas of its brilliant, sunlit background, 

 utterly bewildering to the beholder. 



It is a noteworthy fact, and an interesting theme for study, that the bright 

 colors of almost all hummingbirds are only revealed, or at least only revealed 

 in their full power, when the birds are seen head-on and facing into the light. 

 This is true, indeed, with many other birds of changeable color, but in no 

 other group is it nearly so marked as among the hummingbirds. Many of 

 their brightest "beauty spots" are dead and. dusky except in full front view 

 and lighting. This fact has an interesting bearing on the question of the 

 special uses of hummingbirds' glorious plumage, and suggests several addi- 

 tional possibilities. One of these is that their obliterative coloring is ad- 

 dressed primarily to insects on the flowers and leaves before which they hover, 

 and is therefore offensive rather than defensive. Hummingbirds are so small 

 and lightning-swift that it must be nearly impossible for any predatory birds 

 or beasts to catch them. Tree lizards and small hawks may occasionally 

 seize them while they are perching, although they usually (?) sit on bare, 

 isolated twigs, and are extremely watchful. This watchfulness, however, 

 seems to be directed mainly against other members of their kind (i. e., other 

 hummingbirds, of whatever species), and is aggressive rather than defensive. 

 They are, as is well known, extraordinarily pugnacious, and where several 

 congregate they are continually chasing one another. Nor is this strange 

 animosity exercised solely against their own kindred; with equal frenzy they 

 dart at flycatchers, hawks, eagles, — any flying bird, either big or small, that 

 enters their domain. On the whole, it must be assumed that they enjoy a 

 comparative freedom from the dangers that beset most of the smaller birds. 

 Yet their obliterative equipment is among the finest, and must be of great im- 

 portance to them. The effulgent, steely brightness of their head-colors, often 

 extended outward by erectile tufts and crests, and showing only in full front 

 view, undoubtedly serves to 'veil' them from the sight of insects lurking in 

 and upon leaves and flowers. Without such adornment, the birds would 

 loom up darkly solid between their little victims and the light, thus warning 



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