102 
OUR HOME BIRDS. 
these purposes, for, different from other newly- 
hatched birds, its back, from the shoulders down- 
ward, is very broad, with a considerable hollow in 
the middle. This hollow seems formed by Nature 
for the design of giving a more secure lodgment to 
the egg of the hedge-sparrow or its young one when 
the young cuckoo is employed in removing either of 
them from the nest. When it is about twelve days 
old this cavity is quite filled up, and then the back 
assumes the shape of nestling birds in general/ 
“So, you see, Clara, that, wicked and ungrateful as 
the young cuckoo appears to be, it is but following 
out the instinct of self-preservation, for which abun- 
dant provisional as ^been made by the great Creator, 
‘ who doeth all things well/ 
“We will now return to our cow-bird, which has 
never been seen to push young birds or eggs out of 
the nest, but, by some strange fatality, they invari- 
ably disappear wherever the cow-bird deposits her 
egg. We must look into the matter a little. 
“ In May and June these birds are frequently seen 
loitering singly about solitary thickets, ‘reconnoit- 
ring, no doubt, for proper nurses to whose care they 
may commit the hatching of their eggs and the rear- 
ing of their helpless orphans/ Among the birds 
which they honor with their custom are the blue- 
bird, which builds in a hollow tree; the chipping 
