136 ON THE INSTINCTS OF BIRDS. 
Dr. Darwin states that Pheasants and Partridges 
teach their young to select and take up their food ; 
and hence he seems disposed to infer that all birds 
receive instruction in those particulars ; but that they 
are impelled by instinct, independently of education 
and experience, to exercise the functions of their 
various corporeal organs, whose structure is admir- 
ably adapted to the several offices they have to 
perform, admits of such numerous and decisive 
proofs, that it is truly amazing how a person of so 
much observation as Darwin could have so entirely 
overlooked them. 
Those young birds which do not acquire the use 
of their eyes for several days after they are hatched 
open their mouths for food as soon as they are 
stimulated by hunger, not only when the old ones 
bring it to them, but when any thing approaches the 
nest. Nestlings, too, as soon as they are grown suf- 
ficiently large, mute over the edge of the nest, though 
the parent birds carefully convey to a distance what- 
ever drops from them that they do not succeed in 
ejecting. These actions occur also when birds are 
brought up in confinement, however young they may 
be when taken, and therefore must be instinctive. 
The Common Duck has its toes connected by a 
strong membrane, which enables it to swim with 
facility; and the young of that species, though 
hatched under birds which instinctively avoid com- 
mitting themselves to the water, rush to it with 
