1116 The Zoologist— March, 1868. 



be breeding earlier or later than its six to eight weeks' time for laying* 

 lasts v it will therefore be unable to find for each of its eggs a fitting 

 nest of that species to which it was prepared to entrust it, and to 

 which it was accustomed ; and so it finds itself obliged to introduce 

 one and another egg into the nests of some other species, if haply by 

 good chance it can do so.t Thus, then, it comes to pass that there 

 are, and from the nature of the circumstances there must be, propor- 

 tionably many exceptions to the rule. Thus, too, it comes to pass 

 that by far the greater number of cuckoo's eggs bear the type of the 

 eggs of the whitethroat {Sylvia cinerea) and of the pied wagtail 

 {Molacilla Yarrellii), the most common foster-parents of the young 

 cuckoo;J and perhaps in some localities of the meadow pipit {An thus 

 pratensis), the hedge accentor {Accentor wodularis), and of the reed 

 wren {Sylvia arundinacea) ; and that, on that account, eggs of such 

 colouring form the most frequent exceptions, — that is to say, are most 

 frequently found in the nests of other species. Thus, too, lastly, it 

 comes to pass that these two above-named prevailing colours of the 

 cuckoo's eggs are spread over most localities, whilst at the same time 

 they also appear, almost everywhere, as exceptions in other nests. For 

 the diffusion of these two species (the common whitethroat and the 

 pied wagtail) is very extensive, and their haunts usually offer to the 

 cuckoo also the requirements of its existence: it is therefore not 

 without signification that one seldom finds in their nests cuckoo's eggs 

 of other colours, but one does very frequently find, in the nests of 

 other birds, cuckoo's eggs of their type. 



I will just quote, before I take leave of Dr. Baldamus, the three 

 following deductions, which he draws from his observations, and with 

 which he concludes his paper. 



* "Legezeit" is the concise German word, for which we have no English 

 equivalent. 



■\ The cuckoo, however, alone of British birds, is generally supposed to have the 

 faculty of retaining her egg in the ovarium, after it is arrived at maturity, for a limited 

 period of time. (Montagu's 'Ornith Diet.' Introduction to vol. i. p. 8. Jesse's 

 'Gleanings in Nat. Hist,' vol. ii. p. 125.) If this be correct.it will account for the egg 

 laid by the cuckoo as it fell to the ground after it was shot, recorded by Mr. S. S. 

 Allen, ( l Ibis,' vol. v. p. 358), and by my friend Mr. Chambers (' Ibis,' vol. v. p. 475). 

 See also M. Vaillant's account of the African cuckoo shot by himself, and his faithful 

 attendant, the Hotteutot Klaas, and the frequent occurrence of the egg laid by the 

 cuckoo as she fell wounded from the tree. (Rennie's ' Architecture of Birds,' p. 378.) 



J The pied wagtail, the nxadow p : pit, and the hedge warbler, are perhaps most 

 frequently chosen as the fobtei-pareuts iu this country. 



