Wonderful M'uuicry. 65 



Sharpe assured me, however, that they had in reserve 

 many blue eggs of the cuckoo ; which just leads to 

 the question, in what proportion of cases the brown- 

 spotted eggs are intruded into the hedge-sparrow's 

 nests, as in the three cases noted above. 



Here arises a difficulty about the theory of the 

 cuckoo always laying eggs the same colour. For, 

 if the blue-laying cuckoos know the hedge-sparrow's 

 nest, and use it, these facts would indicate failure on 

 the part of the cuckoos who lay brown-blotched eggs, 

 and place them too in the nests of accentors, or lay /iJ?// uL^ 

 blue or bluish eggs in the nests of birds which have 

 brown, or brown spotted, or blotched eggs. 1 myself, 

 in Essex, last year (1898) found two blue cuckoo's 



the cuckoo's egg is the counter-part of the hedge-sparrow in texture 

 and colour, though almost twice as large — a wonderful instance 

 of mimicr3^ In all the other cases (Nos. 2 — 6), the cuckoo egg 

 is the ordinary dull speckled-brown — a striking contrast. In 

 the case of two other species — the pied fly-catcher (Silesia), and 

 the redstart (Vaalkerstaad), both of which lay blue eggs — the 



cuckoo imitates their colour, but the egg is much larger 



In the following instances the imitative colouring is very perfect : 

 Lesser whitethroat, mottled greenish-grey (Halle, Saxony) ; 

 Orphean warbler, white pale greenish-blue, spotted (Malaga) ; 

 garden warbler, buff-speckled (Brandenburg) ; blue-headed 

 yellow wagtail, grey speckled ( Frank fort-on- Oder) ; barred 

 warbler, pale mottled green (Alsace) ; meadow pippit, reddish 

 brown (North West Cheshire) ; white wagtail, grey speckled 

 (Germany) ; linnet, white greenish spots (Germany). In the 

 case of the red-backed shrike or butcher-bird (Marne), the resem- 

 blance between the two eggs in size and colouring— cream body 

 colour with reddish cloud at the upper end — is so remarkable 

 that one might be pardoned for imagining that there had been 

 some mistake." And yet in spite of the words in this extract, put \ ^ 

 in italics by me, Dr. Bowdler Sharpe unaccountably says there ■ >' 

 is no record of a blue cuckoo's egg in a hedge-sparrow's nest ! 



