464 Thayer, Concealing Coloration. |_Oct. 



and their average background to each other's eyes is the bottom 

 of the sky, not the earth. In the woods the case is still stronger, 

 There even the best-illuminated white is so deeply (green-) shadowed 

 as to average dark green-gray against the actual sky-glimpses 

 above. Its being actually the lightest note in the place simply 

 makes it show least, while black here shows most, — ■ i. e., in every 

 upward direction; which means in half of all directions. In 

 addition to all this, even the brightest white relieves dark against 

 the brighter parts of the forest floor whenever it is itself in deeper 

 foliage-shadow than this background. (For a fuller analysis of all 

 this see my ' Arraignment' article 1 in the ' Popular Science Monthly* 

 for Dec, 1909.) In other words, white in the woods is the least 

 conspicuous of colors, and black the most so, in as many as three- 

 quarters of all directions. Add to this that in patterns it always 

 helps to 'cut up' the wearer; and remember also the wonderful 

 function shown in Figs. 1, 2, 3 and 4 of the above-named 'Popu- 

 lar Science' article. When a white-wing-patterned bird flashes 

 out his flight-whites, all the concealing-faculties of brilliantly 

 contrasted patterns shown in those illustrations spring into play, 

 and trebly so because of motion, when every dark part is as it were 

 chalked over into dimness by each flap of the white-patterned 

 wings. The inevitability of detection through motion had made 

 people suppose it was the patterns that caused the detection. 

 What they do cause is identification after detection. 



Monadnock, New Hampshire, 

 September 1, 1911. 



1 1 shall be delighted to send reprints of this article to all applicants. 



