The Zoologist— May, 1873. 3515 



of prying eyes left the wretched birds which frequented that part of 

 the country, but small chance of rearing any young, I used to start 

 forth in the early summer morning, as soon as the doors of our 

 house were unlocked, and hurrying with my pocket full of small 

 pebbles to the banks of the Thames, where 1 had previously found 

 reed-wrens' nests ; and there no sooner was an egg descried, but 

 it was purloined, and a small stone deposited in its place; and in 

 the case of that species the exchange seemed quite satisfactory, and 

 the unsuspecting birds laid on as if their eggs had never been 

 touched. But this was the only species which I could persuade 

 to be so accommodating : it was not so with the hedgesparrow, or 

 vobm, or yellow-hammer, nor indeed with any other species, so far 

 as I can remember ; * but I should like to know what the ex- 

 perience of others may be on this point, because if it can be 

 proved that ordinarily the sitting bird will accept an intended egg 

 of any colour, then I confess such an argument would be to my 

 mind exceedingly strong against Dr. Baldamus' theory, and it 

 would require very positive testimony in its favour before I could 

 accept it. 



With regard to Mr. Rowley's inquiry for a cuckoo's egg of a 

 blue colour, it seems to me a very legitimate demand, if the theory 

 in question be correct, that such blue cuckoos' eggs should be 

 forthcoming. Mr. Rowley does not evidently consider the blue 

 eggs asserted to be cuckoos' eggs by Dr. Baldamus (Zool. S. S. 

 1151, Nos. 2 and 15; see also p. 1154, No. 15) and Dr. Rey, 

 (Zool. S. S. 3435—3437) to be positively proved to be authentic ; 

 nor does ray friend Professor Newton seem quite satisfied on the 

 point, though he adduces the testimony of Salerne, who a hundred 

 years ago had seen " two stonechals' nests, each containing eggs 

 of that bird, as well as a cuckoo's, which was as blue as the 

 others," and quotes the dictum of the Solognat " that the cuckoo's 

 egg is always blue " (' Nature,' vol. i. p. 74); and though he tells us 

 he had the pleasure in 1861 of being shown by Dr. Baldamus his 

 collection of cuckoos' eggs, of which he says, that his "published 

 figures represent the specimens from which they are drawn as failh- 

 fully as figures of eggs usually do," and amongst which I beg to re- 

 mmd him was one resembling the blue egg of the redstart (Zool. 



* This, my experience of stones substituted for eggs, successful with the reed-wren 

 but unsuccessful with other birds, I communicated to the ' Zoologist ' twenty years' 

 ago (Fii-st Series, p. 4095). '' 



