438 PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. [Dec. 2, 



like all objects so graded inevitably lack appearance of solidity, so 

 that their resultant color passes for a part of their background. 

 Stripes, dots, and all other patterns which are found participating 

 in this graduation in most animarls that live where their background 

 is diversified with corresponding degrees of pattern (as it is in the 

 forest by twigs, dead leaves and little dark holes and the shadows 

 along the under side of light colored twigs) are simply a sort of 

 resultant picture of the average background, just as high-swimming 

 fishes like herring, pompano, bluefish, etc., having no patterns in 

 their background have none on their coats. Chipmunk's stripes 

 are very good rendering of horizontal twigs lighted from above and 

 seen against a more distinct ground." (Also see p. 445). 



15. Protective Coloration and Blending of the Markings 

 IN the Sandpeep. 



After writing this paper I had the opportunity of observing on the 

 Maine coast, September 3, a flock of sandpeeps which were very 

 tame and allowed me to approach in my skiff within a few feet of 

 them. At the distance of from about seventy-five to one hundred 

 feet I could scarcely detect them as they were slowly walking over 

 a little beach of coarse dark gneiss pebbles, the upper part of the 

 oval body being of the same hue as the pebbles ; it was only when 

 within from forty to thirty feet that they could be clearly distin- 

 guished ; it was a clear case of obliteration. On the other hand 

 when standing at the level of my eyes on a dyke of feldspar, their 

 whitish under side blended with the rock when resting, but on the 

 dark gneiss rock enclosing the dike they stood out distinctly. 



The flock was made up of old birds and young ones, the latter so 

 tame that I could approach them in my skiff within about four feet. 



When flying away they reminded me of the hawk-moth, Deilephila 

 lineatay the bars on the wings and neck blending in the same 

 manner, yet the dark and white bands on the body of the young 

 birds remained distinct in slow flight. 



The stripes and bars of no value as recognition marks. — Without 

 entering at length into a discussion of Wallace's theory of recogni- 

 tion marks, which it seems to me has been effectually disposed of 

 by Pocock, it at once struck me in watching these birds on the 

 wing that the light and dark bars and rings so far from being dis- 

 tinct, and thus serving as recognition marks, actually so blended as 

 to make the bird's shape less distinct, and thus the markings were 



