APPENDIX B 

 ADDITIONAL NOTES BY A. H. THAYER 



CONSISTING OF OBSERVATIONS MADE TOO LATE TO BE EMBODIED IN 

 THE TEXT OF THE BOOK 



During the progress of this book I have been discovering another 

 beautiful fact about iridescence — one that vsras, of course, to be expected. 

 The beautiful colors which compose it, and which leap into existence with 

 the changing position of the wearer, or of the beholder, are evidently not 

 mere general attempts at obliteration of the wearer, but are, each, so many 

 perfect color-notes of that background which the changed situation demands. 



We have already shown that the peacock's neck is often leaf-green when 

 looked down at, and pure blue sky-color when looked up at, so that it tends 

 to fit itself exactly to each new background. It is now evident that other 

 animals' iridescences are, like those of the peacock, repertories of exact back- 

 ground colors. The gloss of the magpie's wing is at one moment a glimpse 

 of sunlit evergreen, while the next instant it is the blue snow-shadow beyond 

 the tree. In this way this very snow-picture, so perfectly achieved on the jays 

 by dead color, is reached with equal precision on the magpie by one leap 

 of iridescence. Throughout the world of brilliant animals, we find iri- 

 descence playing this same part. The cormorant's green gloss in the water, 

 looked up at from deeper down, proves to be a perfect match for the trans- 

 lucent water itself. The crow's rainbow sheens, so little thought of as con- 

 cealers, turn him into such true distance-colors as he sits on the nest, as to 

 rank him at this moment almost with the grouse for . indistinguishability. 

 (The nest itself, of course, has the disadvantage of attracting the eye, and 

 thereby subjecting the occupant to a far keener scrutiny than the grouse 



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