THE WKONG TUKNING 85 



it " ; and goes on to say that apparently the hedge- 

 sparrow is, as a rule, more easily " duped " than other 

 birds, such as the red-backed shrike, bunting, redstart, 

 etc. Certainly the hedge-sparrow is much more indif- 

 ferent as to where she builds her nest ! 



I do not, personally, remember the hedge-sparrow's 

 eggs in Mr. Hart's collection where the cuckoo's egg was 

 the " bright blue " spoken of by Archdeacon Wilberforce 

 but in a collection of some forty " clutches " I might 

 easily forget one in particular. Certainly the whole col- 

 lection is very impressive. 



BLANCHE WINDER. 



Ill 



It is, I believe, generally accepted by ornithologists that 

 the eggs of the cuckoo usually resemble in colour, but, 

 of course, not in size, those of the intended foster-mother. 

 The evidence of Mr. Hart's collection of over forty eggs, 

 which I also have seen, would appear to be conclusive 

 on this point, and one can only assume that the egg, to 

 which Miss Hilda Terras refers in her book (which un- 

 fortunately I have not yet read), is an exception to the 

 general rule. 



It is by no means certain how it comes about that 

 cuckoos are able to lay eggs of such varying types. Appa- 

 rently Mr. Hart's theory is that the female decides on 

 the species of bird in whose nest she will deposit her eggs, 

 and that she is then able to transform them in some way 

 so that they resemble those of the bird she has selected. 

 A parallel to this remarkable attribute may be found in 

 the case of the chameleon, which is able to change the 

 colour of its skin at will, but I am inclined to think it 

 more likely that each cuckoo always deposits its eggs in 

 the nest of the same species of bird, and therefore always 

 lays a similar egg. Whether a cuckoo which has been 

 hatched in the nest of (say) a wagtail will lay similar 



