316 Correspondence. [x^ln 



Scissor-tailed Flycatcher in life, and 1 should very much appreciate it if 

 Mr. Barbour, who has enjoyed that inestimable advantage, would take 

 pity on my "ignorance," — of just how one of these birds looks in its 

 native haunts, — which is, of course, profound, and explain what makes it 

 so conspicuous to him. I strongly mistrust that he is thinking of his own 

 interest in seeing a bird of so unusual a shape rather than of the actual 

 conspicuousness of the bird as a mere bird, an article of food for a predatory 

 animal. For all 1 know, the Scissor-tailed Flycatcher may he a conspicu- 

 ous bird in the field, but I venture to guess that if that is the case the 

 reason will be found in its coloration and not in its form. As to the case 

 of the cross fox, 1 am not now prepared to dispute Mr Barbour's statement 

 and I will therefore concede him and Mr. Roosevelt that one point! I 

 think 1 can afford to, and still retain the host of the argument on these 

 disputed cases. As to the possibility of any two species living under 

 precisely the same conditions, I emphatically disagree with Mr. Barbour. 

 Will he deny specifically that a difference in habit constitutes a difference 

 in conditions? As to my opinion of the all-powerfulness of natural selec- 

 tion, lie is certainly drawing on his imagination, tor nowhere in my paper 

 will he find any such opinion, expressed or implied. He has doubtless 

 forgotten that at one point I argued for sexual selection and that I referred 

 to Mr. Beebe's experiments, which have proved that moisture can virtually 

 turn one species into another. I have no doubt, too, that species have 

 occasionally arisen from mutations. The theorem of I,e Chatelier, also, 

 may be applicable, as the chemist \Y. I). Bancroft has suggested. 1 am 

 willing, however, to rest on natural selection as the chief factor in speeiation 

 until a more plausible substitute is offered than has yet appeared. 



As a parting fling, Mr. Barbour attributes to me a "desire to simply 

 bolster up the arguments of a friend." In reply to this I must refer the 

 reader to my already fully stated explanations of the object of my paper, 

 and add that, though I should be proud to call Mr. Thayer my friend, im- 

 personal acquaintance with him is really very slight, and if I had followed 

 the calls of friendship only, 1 should have been led in quite another direc- 

 tion. The paper was written entirely of my own motion, without consul- 

 tation with Mr. Thayer, who never saw it till after it was published, and 

 I alone am responsible for it. 



Of the eight counts of my indictment against Mr. Roosevelt, two remain 

 undisputed, and of the other six 1 think the present letter makes good my 

 claims for all but a single and relatively unimportant one. I should also 

 like to call attention to the fact that of the nineteen pages of my paper 

 only four are devoted to adverse criticism of Mr. Roosevelt. 



I am speaking to a question of personal privilege, ami though on many 

 accounts I should like to say something more on the larger and infinitely 

 more important question of Concealing Coloration. I shall not stray from 

 the point except to ask your indulgence for a few closing words of an 

 impersonal nature addressed directly to the floor. I beg American orni- 

 thologists to study and experiment along these lines for themselves. I feel 



