THE CUCKOO. 
27 
earlier departure, the adult Cuckoos leave their young to find 
their way south by themselves. They are, however^ by no 
means the only birds which act thus. 
I'he history of the young Cuckoo in the nest of tire foster- 
parents is that, being hatched about the same time as the young 
of the rightful occupant, the interloper, while still blind and in 
mi apparently helpless condition, manages to hoist the other 
httle blind nestlings over the side of the nest, so that they 
perish, and it endures to receive the unremitting care of the 
pair of small birds, in whose nest the mother Cuckoo may have 
placed her egg. This story was first related by Dr. jenner, to 
whom we owe the discovery of vaccination, and we have heard 
that some “ anti-vaccinationists ” have carried their fanaticism 
so far, that, from their dislike of the founder of the practice of 
vaccination, they would wish td throw doubts on the authen- 
ticity of Dr.-Jenner’s observations on the habits of the Cuckoo ! 
Some few years ago, however, the proceedings of the young 
Cuckoo, in ejecting from the nest its young foster-brothers and 
sisters, were observed by Mrs. Hugh Elackhurn, wdio sketched 
die operation. We do not know whether the anti-vaccination- 
ists wish to accuse this lady of an untruthful record, but they 
will scarcely be inclined to doubt the evidence of tlie late Mr. 
John Hancock, who also was a witness to the metliod of tlie 
young Cuckoo in ejecting the other occupants of the nest (Tr, 
j^orth. and Durham Nat. Hist. Soc.viii.pt. 2, pp. 210-217, 1886). 
1 he fanatics may not even be satisfied with this evidence, but 
it will be sufficient for every ornithologist. 
The .small size of the egg laid by the Cuckoo, considering 
bulk of the bird, is another peculiar feature in its economy, 
-•reat diversity of colour, also, is one of its ch.aracteristics, and 
Considering the various types of eggs laid by the Cuckoo, it is 
lot wonderful that the theory exists that the bird places its egg 
m the nest of a species, the eggs of which most resemble its 
^wn m colour. That there is great truth in this theory I 
firmly believe, otherwise it woul.d be difficult to account for the 
a Cuckoo’s eggs should be placed in the nest of 
M wliich likewise lays blue eggs. In the British 
in such clutches of eggs, and also blue eggs placed 
blu *■ Flycatcher, the eggs of which are also 
c- Ihe fact of the Cuckoo producing a blue egg was for 
