60 A NATURAL HISTORY OF THE CUCKOO. 
riably, when undisturbed, destroys the eggs of the rightful owner of 
the nest into which it deposits its own ; for otherwise the alien egg 
would be very commonly ejected, as I know from repeated experi- 
ments made with Lark’s eggs, which I have generally used as being 
most similar to those of the Cuckoo. In these experiments I have 
commonly found that, if an egg be placed in a newly-finished nest 
before the owner of it has begun to lay, it is forthwith forsaken ; 
and I have been informed of the Cuckoo’s egg being so deserted, in 
a state of nature. If the alien egg, however, be placed along with 
other eggs, then it is oftentimes discarded ; but if the other eggs be 
removed altogether, and the strange one left alone in their place, 
the chance is very much greater of its adoption. I do not assert 
that the procedure of which I have spoken is invariable, because I 
know to the contrary ; but I affirm that, in the average of cases, the 
results will be as described. 
Now, that the Cuckoo destroys the eggs of her dupe isa fact that, 
strangely enough, has not been generally introduced into the de- 
scriptions of this species ; for which reason I select one or two con- 
clusive instances, to show that I have grounds for the assertion :— 
A Meadow Pipit’s nest was found, with four eggs in it; and on 
looking at it the following day these had all disappeared, and a 
Cuckoo’s egg was in their place. Another nest of the same species 
was found, with two eggs in it; the next day these were gone, and 
a Cuckoo’s egg was in the nest alone ; and the following day the 
Pipit had laid an egg to this, and the day after that another, when 
the nest was taken and brought tome. This narrative relates to 
the identical specimen now in the Ornithological Society’$ collec- 
tion. Indeed, the Cuckoo’s egg is very commonly found alone, or 
when there are others with it, these are ordinarily below their ave- 
rage number, intimating that they had been laid subsequently to the 
deposition of the alien. My friend Mr. Hoy has communicated the 
following observation to The Magazine of Natural History. “I 
once observed a Cuckoo,” relates that naturalist, “ enter a Wagtail’s 
nest, which I had noticed a short time before to contain one egg ; in 
a few minutes the Cuckoo crept from the hole, and was flying away 
with something in its beak, which proved to be the egg of the Wag- 
of some magazine, in which an instance is recorded of a young Cuckoo being 
imprisoned in the hole of a tree, having outgrown the size of the aperture 
through which the egg must necessarily have been introduced! It may, 
notwithstanding, have been dropped in, supposing the cavity to be shallow, 
and pretty well filled up with nest materials, a circumstance of which I have 
no information. 
