1904:] PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. 445 



It will be remembered that on the outer margin of the wings of 

 Papilio asterias there is a row of rather large round yellow spots on 

 a black-brown ground. I pasted near the edge of a six-inch black 

 disk several roundish dark buff spots nearly an inch in diameter. 

 On revolving the disk, the spots formed a wide dark yellowish-gray 

 b^nd. The result was that the edge of the disk was made indis- 

 tinct ; the same effect is apparently produced by the yellowish 

 spots on the butterfly's wing. A member of my family noticed 

 that in a Papilio thus ornamented the outline of the wings was dur- 

 ing flight blurred and made indistinct. Also the ground beetles 

 Anthia and others, the Cicindelidae and Mutillidse are ornamented 

 with large conspicuous yellow dots or spots which probably more or 

 less blend. 



I stuck on the same black disk five one-half-inch buff bands. On 

 slowly turning the wheel two black rings were formed, the ground 

 color of the disk being dark buff; on more rapidly turning the 

 wheel a general dusky buff hue pervaded the disk. 



In revolving a half or a three-quarters black disk over a white one 

 the colors blended into gray. A disk half green and half black 

 formed a darker green, and a disk three-quarters green and one- 

 quarter black blended into a slightly darker green. A disk one- 

 half or two-thirds yellow, the rest Venetian red, upon revolving 

 produced a deep orange hue, A disk three-quarters yellow and one- 

 quarter Venetian red produced an ochre-yellow, less deep than the 

 orange effect. On revolving a disk one-half blue and one-half 

 yellow a royal purple hue resulted. 



From these experiments it appears to result that in any striped or 

 spotted animal, when rapidly running or flying, the stripes or spots 

 must inevitably tend to be confused or blended; and when the 

 ground color and stripes or spots are of opposite hues, as black and 

 white, the result will be a pearl-gray or cloud-like neutral tint, thus 

 obliterating or at least obscuring the outlines of the body. Thus 

 birds like the loon, pigeons with their barred wings, moths and 

 butterflies with striking bands of very different hues, the tiger or 

 zebra with its stripes, and the ocelot with its spots, tend when 

 rapidly moving to become obscured to the vision, and to harmon- 

 ize with the earth or sky. 



The following experiment was less satisfactory than the foregoing. 

 I fastened a stuffed chipmunk with its back upward on the outer 

 edge of a large disk of white pasteboard. On revolving it slowly on 



