4oO Allen, Roosevelt on Concealing Coloration. [oct. 



In an article by Mr. Thayer printed in the present number of 

 this magazine (antea, pp. 460-464) we get perhaps a clearer view 

 of what he now claims for his investigations than can be obtained 

 from his book and previous papers. He says (/. c, p. 463): "The 

 oft -repeated objection that the wearers of these costumes perpetu- 

 ally reveal themselves by motion, and that consequently my tests 

 give a wrong impression, is just what shows lack of taking in what 

 my investigation is. My whole assertion is that the costumes of 

 these creatures are not what reveal them, and the objector's 

 repeated declaration that the real animal moves and shows himself 

 simply backs me up. The use of motionless stuffed skins is the 

 pure method of studying the effect of the patterns apart from that 

 of motion . . . .The inevitability of detection through motion has 

 made people suppose it was the patterns that caused the detection. 

 What they do cause is identification after detection." 



If animals with conspicuous patterns and contrasting colors 

 were always motionless, and always chose for resting places back- 

 grounds that match their patterns and conspicuous colors, Mr. 

 Thayer's experiments with stuffed skins and carefully chosen or 

 artificially prepared backgrounds would have some direct bearing 

 on the question of the effect of such patterns and conspicuous and 

 contrasting colors. But since an animal or bird however colored 

 is apt to remain unseen if motionless, especially if physically 

 screened in the least degree, and since most conspicuously colored 

 animals invariably pass a large part of their time in the open and 

 in motion, without the aid of any matching backgrounds, but 

 exposed to an ever varying background, the utility of Mr. Thayer's 

 " pure method of studying the effect of the patterns apart from that 

 of motion" does not seem very evident, a point repeatedly urged 

 by Mr. Roosevelt in the paper here under review. 



