GRASSHOPPER- WARBLER 



running, or flying away from her suitor — indeed, I cannot call 

 to mind a single instance in which I have, even for a brief 

 moment, seen the female looking at the male while assuming 

 these positions — and therefore has her back turned to him 

 when we ought to expect her to be examining the details of 

 his plumage. It might be here argued that for the female to 

 get the general effect of the male's display would, through 

 such immense periods of time, be sufficient to account for the 

 beauty of the plumage ; but I cannot bring myself to believe, 

 even if the other and more weighty objections could be 

 removed, that such a casual inspection could be the means of 

 developing minute and beautiful patterns, the very delicacy of 

 which must surely cause us all to marvel. This, however, we 

 know, that as a bird grows older the colours of the plumage 

 become intensified, and even the plumage itself becomes finer 

 in quality, and amongst the Warblers this difference is so 

 marked as to at once arrest attention. He, then, who 

 supports the principle of selection must admit that the older 

 males being more richly coloured would be first selected ; he 

 must also admit that the offspring of these more successful 

 males could inherit no advantage, inasmuch as the success of 

 their parents was due solely to laws of continuous growth. 



" Early in July a courtship, similar in every 



respect to the one in spring, occurs amongst the 



Sedge- Warblers." 



Admitting the principle of selection, we must nolens volens 



assume this to be a selection taking place before the second 



brood, conclusively proving the choice of the female in the 



first instance to have been a mistake. 



" The ultimate production of the most healthy and 

 most beautiful offspring by the selection of certain 

 males is, without a corresponding selection amongst the 

 females, impossible, and of the existence of such selec- 

 tion in any form there is no evidence." 

 Individuals of both sexes vary very considerably both in 

 intensity of colouring and actual quality of plumage. As an 



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