Observations on the Cuckoo. 333 



a little inclined to suspect, also, that, whilst the generality of 

 wild birds mostly lay their eggs early in the morning, at least 

 before ten o'clock p. m., the cuckoo does not lay hers till 

 much later in the day, which, in general, would prevent her 

 from being surprised by the owners of the nest; for, from 

 the time when a nest is finished, to that when the bird begins 

 to sit, the latter is but rarely seen, during the day, about the 

 place, as this would not unfrequently only lead to its disco- 

 very. Should these remarks, however, be so fortunate as to 

 meet the eye of Mr. Hoy, I hope he will favour us with the 

 exact time of day in which he actually observed the cuckoo 

 to lay. 



The cuckoo most usually (probably always when undis- 

 turbed ) destroys 'whatever eggs there may be in a nest into "which 

 she introduces her own; and, therefore, whenever any other 

 eggs are found in the same nest with that of the cuckoo, they 

 were not laid, in most instances, until after its deposition. 

 Of this fact I have such multitudinous evidence, and from so 



observed in the text) have frequently seen her flying about from bush to 

 bush, and from thicket to thicket, as if hunting for birds' nests ; but, in an 

 enclosed part of the country, it is no very easy matter to follow her up as 

 Wilson's informant did the American bird. Upon consideration, I think 

 the two species proceed very much in the same manner; and, judging from 

 my own past exploits in the way of birds'-nesting, I cannot conceive that 

 the cuckoo is ever very long in finding a proper receptacle for her egg. 

 For an hour or two, undoubtedly, all birds have a voluntary power 

 of retaining or expelling an egg ; and so, of course, the cuckoo has 

 among the rest : but to suppose that she can retain it in the oviduct till 

 quickened by the heat of her own body, appears to me to be entirely out 

 of the question. — May 20th. I have since had some conversation with 

 Mr. Yarrell upon this subject, a gentleman whose opinion is a very high 

 authority in all matters connected with natural history. He has informed 

 me that there are cases in which a common fowl has been known to 

 retain her egg for several days on being removed to a strange yard, even 

 though she were in the middle of a set ; but the like of this cannot 

 well take place in a state of nature. On the other hand, I have known 

 instances wherein both fowls and pigeons have been compelled to drop 

 their eggs even whilst upon a perch. I also remember to have seen a 

 sparrow hovering for a long time over a particular spot in the Surrey 

 Canal, and, upon going to see what was the object of its attention, I was 

 surprised to find that it had dropped an egg into the water. A day or two 

 ago, also, 1 found that a skylark had laid an egg upon the bare ground, 

 upon a spot whence her nest had been removed the day before. However, 

 in ordinary cases, I suspect that a bird has much the same power over the 

 functions of the oviduct as we have over those of the rectum and vesica. 

 Mr. Yarrell is of opinion that the vital action in an egg cannot commence 

 whilst it remains within the oviduct, however long it may there continue ; 

 upon the principle that all contact with the external air is there as com- 

 pletely shut out as if the shell had been covered over with a coat of var- 

 nish. * I have now, however, some experiments pending, the results of 

 which will throw some light upon this subject. In the meantime, we must 

 not entirely forget the case of ovo-viviparous animals. 



