Page:Popular Science Monthly Volume 75.djvu/571

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THEORIES OF MIMICRY
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humidity goes always a corresponding enriching of the vegetation which forms the species' background. Let these investigators push through the mangroves that border this sultry aired forest against the bare sands of the gulf, and they will find, two steps out upon the beach, in a saturated ocean atmosphere, a beach and ocean fauna of the purest beach and ocean colors, palest gray and pearl.

Black-and-gold is as truly the background color of the flower haunting black-and-gold wasp, as is stone-weed-and-sand color of the stone-and-weed-and-sand colored sandpiper. Scarlet and yellow fruit colors, sky-blue and green leaf colors, on the macaw, are as absolutely the picture of this bird's background while he is dangerously absorbed in feeding in a tropical fruit tree, as is the little terrestrial mammal's brown the picture of the universal earth-brown on which he lives. The thousands of species of open ocean fish, the bare sand-dwellers and the ocean-air-fliers, all wear only the colors that characterize their backgrounds, often adding for the breeding season bits of the scenery of their nesting place, as in the case of puffins, whose gaudy breeding-season-bill on guard at the mouth of the burrow, obliterates the dark hole itself, and at the same time substitutes a semblance of flowers to complete the deception. The moment these domestic duties are over, and the puffin back in the open sea, we behold him dressed again in the universal ocean-and-rock colors of his habitat. (To show that no physiological difficulty prohibits fish, for instance, from wearing gaudy colors, we find such colors upon them wherever they live amidst brilliant corals and brilliant water-plants.)

To complete the above argument, notice that, as my illustrations show, it is in the midst of vegetation, or other confusing and more or less eclipsing surroundings, that monochrome is far the best costume for identification, while out in the open spaces, the air, the beach, and the sea, there, where no twigs or other forest details threaten to confuse the identity of pattern, striking devices of all kinds would have their fullest chance to effect the identification for which they have been supposed to exist. And what do we find? We find nature foregoing, from end to end of the world, every chance to make use of this obvious opportunity.

Furthermore, to show that it is not a matter of regions, notice, as I have pointed out, the gilded wasps living within a few feet of earth-colored ants, and little earth-colored rodents swarming on the brown forest floor, two feet below bright dressed inhabitants of the bright dressed overhanging foliage. Why do not these rodents, forever preyed upon, in fact the stand-by diet of carnivora in every order, why do they not develop unpalatability and badges? All attainable unpalatability they must possess, after their immeasurable period of being picked from, but why not the badges? The truth appears to be that all advantageous attributes have, in every animal, grown side by side, and that the cul-