GATHERED BY THE WAY 



Mr. Wallace thinks that the bird-eater mimics the 

 insect-eater, so as to deceive the birds, which are 

 not afraid of the latter. But if the two hawks look 

 aUke, would not the birds come to regard them both 

 as bird-eaters, since one of them does eat birds? 

 Would they not at once identify the harmless one 

 with their real enemy and thus fear them both alike ? 

 If the latter were newcomers and vastly in the minor- 

 ity, then the ruse might work for a while. But if there 

 were ten harmless hawlcs around to one dangerous 

 one, the former would quickly suffer from the char- 

 acter of the latter in the estimation of the birds. 

 Birds are instinctively afraid of all hawk Idnd. 



Wallace thinks it may be an advantage to cuckoos, 

 a rather feeble class of birds, to resemble the hawks, 

 but this seems to me far-fetched. True it is, if the 

 sheep could imitate the wolf, its enemies might keep 

 clear of it. Why, then, has not this resemblance 

 been brought about ? Our cuckoo is a feeble and 

 defenseless bird also, but it bears no resemblance 

 to the hawk. The same can be said of scores of 

 other birds. 



Many of these close resemblances among different 

 species of animals are no doubt purely accidental, 

 or the result of the same law of variation acting 

 under similar conditions. We have a hummingbird 

 moth that so closely in its form and flight and man- 

 ner resembles a hummingbird, that if this resem- 

 blance brought it any immunity from danger it 

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