1904.] PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. 439 



of no avail, producing the contrary effect of rendering these birds 

 unrecognizable by their own species. And this it is obvious will 

 apply to any birds and beasts similarly marked. Yet it may be that 

 the white rump of deer, etc., may when the creatures are walking 

 or slowly running serve as a guide to those following, as allowed 

 by Pocock. 



16. Blending of Black and White Bars in Moths, Butter- 

 flies, ETC. 



Blending of the bars m moths. — The flight of certain species of 

 geometrid and pyralid moths, which are black marked with broad 

 white bands, many years ago attracted my attention. When any 

 of these smaller moths, such as the geometrids mentioned below and 

 Desmia funeralis and other black and white Pyralids, are rather 

 rapidly flying away from one the singular effect is that of whirling 

 incomplete black and white broken circles, making the outlines 

 of the body and wings confused, which, added to their irregular 

 flight, renders them difficult to catch. 



I well rem.ember when on the Labrador coast in 1864, where the 

 geometrid moth, Rheumaptera hastata, was abundant, flying in con_ 

 siderable numbers, the peculiar effect on my mind of its flight. 

 This moth has broad black wings, marked with conspicuous white 

 bands or bars. It ranges from the Arctic regions to Maine. In its 

 uncertain devious flight the effect of the moth in its not^particularly 

 rapid flight was that of black and white incomplete and confused 

 rings circling through the air. This partial blending of the white 

 and black bands, added to the zigzag, uncertain flight, would make 

 it very difficult for a bird to follow and seize such insects, which 

 when disturbed fly by day and are thus protected. There are sev- 

 eral other boreal or Arctic geometrids similarly marked, and also 

 the species of Heliom.mata and Euchoeca (Baptria). 



Blending of the black and yellow stripes of Papilio turnus. — On 

 June 22, 1902, at Brunswick, Me., I for some time watched this, 

 butterfly leisurely flying from flower to flower. It seemed to me 

 that during its flight there was a slight blending of the pale yellow^ 

 orange of the wings with the black ground color, so that the general 

 effect was that of pale yellow. A member of my family indepen- 

 dently noticed the same blending and corroborated my own obser- 

 vations. She noticed that the black borders of the wings were ren- 

 dered less distinct by the blending of the series of round yellowish 



