BRITISH WAKBLERS 



instance : The male Blackcaps, when excited with one another, 

 or with another species, such as Sylvia hortensis, assume the 

 same positions as when courting the females. To what do 

 these facts point ? Certainly not to a conscious display. 



Further evidence, details of which I need not enter into 

 here, prove that all these actions are intimately associated 

 with the development and stimulation of the sexual organs. 



When we come to consider all these facts, when, on the 

 one hand, we find evidence of so strong a character opposed 

 to the theory of sexual selection, and on the other, find that 

 actions similar in every respect are frequently performed at 

 other periods of great excitement in a bird's life, can we doubt 

 the probability of their being solely reflex in kind? 1 I think 

 not. All the difficulties would thus be removed, the second 

 courtship of the Sedge-Warbler— a courtship which, although 

 I have not hitherto seen it, yet in my opinion undoubtedly 

 occurs amongst other species — is explained ; and there would 

 only remain the general argument, namely, that it is impossible 

 to believe that all the trouble which many species apparently 

 take with their courtship is purposeless: and this argument 

 may be raised against the theory of reflex action ; but because 

 I exclude conscious choice from being in any way directly 

 responsible for these actions, I by no means wish to imply 

 that they are purposeless, neither am I prepared to enter 

 into further explanation here, for I hold that with the very 

 meagre knowledge that we, even at the present day, possess 

 of all the facts relating to this most interesting subject, it 

 would be unwise to attempt to formulate a theory in explana- 

 tion of their ultimate purpose. 



The peculiar manner in which these birds walk along 



^n his "Last Words on Evolution," Professor Ernst Haeckel considers 

 " sexual selection" of the greatest importance, both for the general theory 

 of evolution and also for psychology, anthropology, and aesthetics. Since 

 the importance of it is so great, no labour, surely, ought to have been spared 

 to have verified the completeness of the fundamental evidence upon wbich 

 it was originally based ? 



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