by reason of their brighter plumage. Thus the duller coloured 

 males died without offspring. On this assumption each 

 succeeding generation would be, in some slight degree, 

 brighter than the last, until the process of transformation 

 ended in the glorified creatures we so admire to-day. 



It would be foreign to the purpose of this book to pursue 

 this theme at length. Let it suffice to, say that while the 

 " Sexual Selection " theory still holds good, it has, so to 

 speak, changed its complexion. And this largely owing to 

 the accumulation of new facts. For the most important of 

 these we are indebted to the singularly exact and laborious 

 observations analysed, clarified, and inteipreted with remark- 

 able insight and sagacity of Mr. H. Eliot Howard, one of the 

 keenest ornithologists of our time. He has set forth his 

 case, and interpreted his facts with masterly skiU, and there 

 seems no escape from his conclusions. Briefly, he has shown 

 that birds of quite sober coloration hke the warblers, which 

 formed the basis of his investigations, engage in displays 

 quite as remarkable, and of precisely the same character as 

 in birds of gaily colomred plumage. From this it is dear 

 that this wing-play is not prompted by a more or less con- 

 scious desire to display conspicuously coloured patches of 

 colour, for of colour there is none save that of the general hue 

 of varjTing shades of brown, as in the case of the grasshopper 

 warbler, for example. Nor is the display, apart from colour, 



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