402 CUCULID^. 



well-known fact that abnormally-large eggs are mostly 

 deficient in depth of colour and in stoutness of shell, 

 neither of which characters is observable in Dr. Baldamus's 

 specimens ; and, that, though no doubt more precise and 

 delicate examination than any to which they seem to have 

 been subjected were desirable, some other evidence in favour 

 of his having rightly assigned them is to be considered. 

 Thus Herr Braune at Greitz shot a hen Cuckow as she was 

 leaving the nest of an Icterine Warbler, and found (Nau- 

 mannia, 1853, pp. 307, 313) in the oviduct of the former 

 an egg coloured very like that of the latter, while on looking 

 into the nest he saw there an exactly similar egg, which 

 there can be no reasonable doubt had just been placed there 

 by that very Cuckow.* Again, Herr Grunack (Journ. fur 

 Orn. 1873, p. 454) has since found one of the most abnormally- 

 coloured specimens — a blue one — to contain an embryo so 

 fully formed as to shew the characteristic zygodactyl feet of 

 the bird, thus proving incontestibly its parentage.! Now 

 both of these being extreme cases, the question is worthy of 

 serious attention, but we must also bear in mind the far more 

 numerous instances in which not the least similarity can be 

 traced, as in the very common case of the Hedge- Sparrow 

 already mentioned, and if we attempt any explanatory 

 hypothesis it must be one to fit all round. But any such 

 hypothesis must needs be based mainly on speculation, and 



* Herr von Homeyer (Ornith. Centralblatt, iii. p. 75) has objected to this 

 statement as relating an impossibility, arguing that in no bird do the fully- 

 coloured eggs follow each other so quickly that two such are simultaneously ready, 

 and least of all in the Cuckow, where the intervals of laying are presumably 

 long ; but Herr Braune's statement is supported by the evidence of Saxby (Zool. 

 pp. 8165-8168), who shot a Cuckow carrying an egg which she must have laid 

 some time previously, and afterwards discovered a second and perfect egg in 

 her ovary. A case almost exactly parallel is cited by Thompson (B. Irel. iii. 

 pp. 442, 443) on the authority of Kinahan, corroborated in certain particulars 

 by Mr. J. Haughton, the late Mr. R. Ball and Prof. Allman. Here an egg which 

 the bird was carrying in her mouth, was seen by the first two of these gentle- 

 men to fall from it, while two full-grown eggs, one of them ready to pass into 

 the oviduct, were found on dissection by the last witness. The often-repeated 

 assertion that Cuckows' eggs are only laid at several days' interval cannot there- 

 fore be accepted unconditionally. 



t The like fact is recorded by Mr. Seebohm (Zool. 1S80, p. 361). 



