1913 I Barboue, The Case of Roosevelt »»s. Thayer. 91 



birds, pink birds, green and yellow, and black and red, and black 

 and green, and magenta birds, sky blue birds and brown birds of 

 many shades, and many with a bewildering number of conspicuous 

 shapes. We use these words advisedly. Can these birds all be 

 equally protected under the same or almost the same conditions? 

 We ask Mr. Thayer frankly to tell us that if such and such types of 

 coloration are concealing. as he says they are, are not perhaps such 

 and such other types of coloration equally conspicuous; and then 

 let us see whether in the environment under discussion, we cannot 

 perhaps find these or similar types of coloration displayed by birds 

 apparently as successful as those supposedly protected by colora- 

 tion. In other words, we ask Mr. Thayer to answer our questions, 

 to meet our arguments fairly and squarely, and not simply to fall 

 back on dogmatic assertions, based upon his interpretation of the 

 physical laws of human optics. It may seem futile to keep bandy- 

 ing words back and forth. The subject is one, however, which is 

 well worth the opening up it is just beginning to receive. We have 

 been severely criticised by Mr. Thayer for our previous review of 

 his work. We hope now that he will come forward and meet our 

 arguments, not with other examples of his own discoveries, but 

 with definite answers to the questions which we have put to him, 

 now and hitherto. Why should flamingoes be pink, if they lack 

 enemies? Why should sea birds be protected when many of them 

 apparently have no enemies at all? How can black birds, white 

 birds, green birds, and brown birds all be equally protected in the 

 same forest by the same light rays filtering through the same green 

 foliage? 



