MR. J. H. GURNEY ON TOE ECONOMY OF THE CUCKOO. 371 
some are much larger than others, and probably some are harder than 
others I have found Cuckoo’s eggs uninjured outside the nest, and 
on other occasions the foster-parent’s eggs outside the nest sometimes 
uninjured. I have more than once found the Cuckoo’s egg uninjured in 
a nest with the foster-parent’s eggs all broken, but in such cases usually find 
very many feathers of foster-parent, and sometimes the dead foster-parent 
outside the nest. I always think this is an accidental termination of the 
usual scullle, or that the mischief is done by some other animal. One often 
sees a continued scuffle between a Cuckoo and one or more small birds, in 
play or in enmity I think we should more often find two or more 
Cuckoo’s eggs in one nest, but that I fancy the second and succeeding 
Cuckoo would bo likely to tako out the biggest egg ( i.e ., the previous 
Cuckoo’s), rather than a smaller egg of foster-parent.” 
Cuckoos’ Fosterers. 
Judging from the excellent lists of fosterers by Mr. Edward 
Bidwell in our ‘Transactions’ (vol. iii. p. 526), Mr. Dresser and 
Mr. W. Bladen (published separately, 1896), there is no species of 
bird in the least degree suitable whose nest the Cuckoo will not 
occasionally lay in. It would be more indicative of nature’s intended 
limit if a list was written, giving us the species in whose nests 
Cuckoos had been actually hatched, because the deposition of its 
eggs in abnormal nests merely indicates that the Cuckoo could find 
nothing else handy wherein to put them. An egg once laid must be 
put somewhere, even in au unfinished nest.* Cuckoo’s eggs have been 
found in the domed nestof the Wren, but I ordy find one instance of a 
Wren’s Cuckoo being reared, and cannot imagine how the imprisoned 
Cuckoo ever gets out of such a small hole (.7 x .8) as a Wren’s. 
Yet there must be Cuckoos whose mission in life is to be parasitic 
to the Wren, for it seems pretty clear that individual Cuckoos, 
when they can, introduce their eggs into the nest of one species 
only; but according to Dr. Key they never lay eggs which resemble 
Wren’s eggs. But in this lie may be wrong (c/. Zool. 1895, p. 22S ; 
‘ Birds of Europe,’ vol. v. p. 207), as he certainly is about the 
Hedge Sparrow. The Rev. Maurice Bird found a Cuckoo’s egg in 
a House Sparrow’s nest in Kent, which is rare, but the Sparrow’s 
nest was in a clipped Spruce Fir hedge. Mr. J. A. Cole found and 
brought to my father a Cuckoo’s egg in a Redstart’s nest at Catton, 
in a small tin kettle, and here again the question arises, “ How 
would the young Cuckoo have got out of the kettle ? ” 
* Mr. Bird found one in an unfinished Hedge Sparrow’s nest at Somerton. 
