460 Letters, Extracts, and Notes. [Ibis, 



that, when convenient, a Cuckoo prefers always to lay her 

 entire clutch in nests of one selected species. 



There is such an extraordinary range of variation in eggs 

 of the same species that it is not surprising that the Cuckoo 

 is no exception to the rule ; the only puzzling thing, is that 

 some Cuckoos^ eggs are such perfect, slightly enlarged, 

 replicas of the eggs of the other species that one can hardly 

 suppose the resemblance to be objectless ; and y&t many 

 birds seem to have so little appreciation of the character of 

 their own eggs that they readily accept marbles or hazel- 

 nuts as substitutes, and I have even known a Blackbird to 

 accept a rather angular flint and attempt to hatch it out. 



Yours truly, 

 Beckenham, Kent. ARTHUR G. BuTLER. 



13 April, 1917. 



Sir, — In the list of species breeding in England in 

 whose nests the eggs of the Cuckoo have been found 

 (p. 222 ante), Major Meiklejohu does not mention the 

 Reed-Bunting. The late John Cottney took several clutches 

 of Reed-Bunting^s eggs containing an egg of the Cuckoo in 

 this neighbourhood, one of which is in my collection, and 

 I believe there are one or two others in his collection now 

 in the Belfast Municipal Museum. 



Yours truly, 

 Hillsborough, Nevin H. Foster. 



Co. Down, 

 16 April, 1917. 



Sir, — I read with interest '' Some Reflections on the 

 Breeding-habits of the Cuckoo" by Major R. F. Meiklejohn, 

 D.S.O., M.B.O.U., in your April number. There are, 

 however, certain points in his paper to which I should like 

 to call attention, and on which I should be glad of further 

 information. 



I wish to deal with facts as apart from theories. Personally 

 I am a great deal more interested in the former than the 

 latter. 



