172 HABITS OF BIRDS. 
soon as it acquires the requisite strength of foot, 
which occurs a very short time after it is hatched, 
takes to the water and swims as dexterously as its 
mother herself can do. Nay, it cannot only swim 
so as merely to keep itself afloat, but it knows, 
without any instruction, how to proportion the fre- 
quency and force of the strokes of either foot so as 
to carry it to any part of the pond it chooses, as ac- 
curately as if it were profoundly acquainted with 
the mathematical problems of the composition and 
resolution of forces. No instruction nor imitation 
of the parent will account for this, inasmuch as 
ducklings hatched in an oven will take to the water 
as readily as those tended by a female duck ; and, in 
the common occurrence of their being hatched un- 
der a hen, they will swim away and leave their fos- 
ter-mother on the bank of the pond in utter despair 
for their safety. This proves not only that they 
can swim without instruction, but in opposition to 
the most earnest solicitude of their sole instruct- 
ress. We have witnessed a similar case, no less 
in point, in a brood of turkeys hatched by a goose, 
which their foster-mother, as was natural, was de- 
sirous of leading into the water, but this they re- 
fused as obstinately as ducklings do to quit the wa- 
ter when recalled by a hen. 
We think it highly probable that the instances of 
the eagle and the stork above quoted, admit of a 
similar solution into instinctive motives independent 
of instruction. Even the case of the hen, who leads 
her chickens so assiduously to where they may 
find food, though it appears to be more like instruc- 
tion than the instances of the eagle and the stork, is 
far from being conclusive; for chickens which are 
hatched artificially seem to be at no loss in learn- 
ing to feed, though they have no mother; and ducks 
hatched under a hen will take the water in spite of 
her most anxious warnings. 
The swallows and sparrows, which, from building 
