CUCKOW 121 
stadt, who says (Zoolog. Garten, 1866, pp. 374, 375) that through a 
telescope he watched a Cuckow as she laid her egg on a bank, and 
then conveyed the egg in her bill to a Wagtail’s nest. Cuckows 
too have been not unfrequently shot as they were carrying a 
Cuckow’s egg, presumably their own, in their bill, and this has 
probably given rise to the vulgar, but seemingly groundless, belief 
that they suck the eggs of other kinds of birds. More than this, 
Rowley, who had much experience of Cuckows, declared (Ibis, 
1865, p. 186) his opinion to be that traces of violence and of a 
scuffle between the intruder and the owners of the nest at the time 
of introducing the egg often appear, whence we are led to suppose 
that the Cuckow ordinarily, when inserting her egg, excites the 
fury (already stimulated by her Hawk-like appearance) of the 
owners of the nest by turning out one or more of the eggs that 
may be already laid therein, and thus induces the dupe to brood all 
the more readily and more strongly what is left to her. Of the 
assertion that the Cuckow herself takes any interest in the future 
welfare of the egg she has foisted on her victim, or of its product, 
there is no evidence worth a moment’s attention. 
But a much more curious assertion has also been made, and one 
that at first sight appears so incomprehensible as to cause little 
surprise at the neglect it long encountered. A‘lian, who flourished 
in the second century, declared (De Nat. Anim. III. xxx.) that the 
Cuckow laid eggs in the nests of those birds only that produced 
eggs like her own—a statement which is of course far too general ; 
but in 1767 currency was given to it by Salerne (L’hist. Nat. Ois. 
p. 42), who was, however, hardly a believer in it; and it is to the 
effect, as he was told by an inhabitant of Sologne, that the egg of 
a Cuckow resembles in colour that of the eggs normally laid by the 
kind of bird in whose nest it is placed. In 1853 the same notion 
was prominently and independently brought forward by Dr. 
Baldamus (Nawmannia, 1853, pp. 307-325), and in time became 
- known to English ornithologists, most of whom were sceptical as to 
its truth, as well they might be, since no likeness whatever is 
ordinarily apparent in the very familiar case of the blue-green egg 
of the Hedge-Sparrow and that of the Cuckow, which is so often 
found beside it.2 Dr. Baldamus based his notion on a series of eggs 
in his cabinet, a selection from which he figured (op. cit. 1854, pl. v.) 
1 The earliest instance of this in the British Islands seems to be that 
reported by Thompson (B. Jrel. iii. p. 472); another was recorded in 1851 
(Zool. p. 8145) ; but Le Vaillant seems to have been the first to discover the fact 
in a South African species (Ozs. d@’ Afr. v. pp. 47, 48), and untrustworthy witness 
as he was, in this case he seems to have spoken truly. 
2 An instance to the contrary was recorded by Mr. A. C. Smith (Zoologist, 1873, 
p. 3516) on Mr. Brine’s authority, and a few others have since been observed. 
3 This series was seen in 1861 by the writer. 
