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haphazard collection here there are, I think, seventeen clutches 

 of different species, and about the same number of differently 

 coloured cuckoos' eggs, and yet in a very few of these clutches 

 does the cuckoo's egg in the very slightest way resemble the 

 eggs of its foster mother. Now, according to evolution, long 

 ago, the surviving cuckoos should be those who have escaped 

 destruction by depositing an egg in a clutch resembling their 

 own. So far, however, is this from the real case, that though 

 nearly fifty per cent, of the cuckoos' eggs found in this country 

 are in a hedge sparrow's nest, hardly ever is the well-known 

 blue variety found in the blue clutch of the fosterer. 



We all know the redstart also lays a blue egg, almost 

 exactly like the hedge sparrow, and curiously enough when a 

 cuckoo's egg is found in the clutch it is nearly always a blue 

 one. As however the redstart builds in a hole in a tree or post, 

 the protective colouring seems quite unnecessary. There are, 

 however, two exposed nests in which, if a cuckoo deposits an egg, 

 it nearly always resembles the clutch, the brambling and the 

 Orphean warbler. I have an example of the latter in my own 

 collection, and the size only betrays the intruder, and there is 

 one or more in the Natural History Collection at South 

 Kensington. I believe abroad the cuckoo is as partial to this 

 nest, as in England it is to the hedge sparrow's, so much so that 

 frequently two cuckoo's eggs are deposited in the same nest. 

 But now you will naturally say why raise all these difficulties 

 about protective colouring ? Well, for years I could see no 

 proofs of the great scheme of evolution except those two small 

 component parts protective colouring and mimicry. I was 

 therefore glad to try and adopt a theory of colouration that did 

 not clash with a special creation. But it is far easier to destroy 

 than to build up and I can only hope you will look leniently 

 upon a principle that I only know as yet in its infancy. 



The theory I wish to call your attention to I may call 

 colour-sensitiveness based somewhat on the popular chameleon 

 principle. Professor Poulton, one of the greatest entomologists, 

 gives in the Entomological Society's Transactions for 1903 some 

 astounding results in his experiments upon the colour-relation 

 between lepidopterous larvae and their surroundings. 



He sums up as follows : — 



" A very large number of records proved that the larvae 

 rested by day upon the object they afterwards came to resemble." 



