Contributions to the theory of natural selection. A series of essays ... By Alfred Russel Wallace ...

MIIE PHILOSOPHY OF BIRDS' NESIS. 223
the time they are learning to fly and return often to
the nest, they must be able to examine it inside and
out in every detail, and as we have seen that their
daily search for food invariably leads them among the
materials of which it is constructed, and among places
similar to that in which it is placed, is it so very
wonderful that when they want one themselves they
should make one like it? How else, in fact, should
they make it? WXould it not be much more remarkable if they went out of their way to get materials
quite different from those used in the parent nest,
if they arranged them in a way they had seen no
example of, and formed the whole structure differently
from that in which they themselves were reared, and
which we may fairly presume is that which their whole
organization is best adapted to put together with celerity and ease? It has, however, been objected that
observation, imitation, or memory, can have nothing
to do with a bird's architectural powers, because the
young birds, which in England are born in May or
June, will proceed in the following April or May to
build a nest as perfect and as beautiful as that in
which it was hatched, although it could never have
seen one built. But surely the young birds before
they left the nest had ample opportunities of observing
its form, its size, its position, the materials of which
it was constructed, and the manner in which those
materials were arranged. Memory would retain these
observations till the following spring, when the materials would come in their way during their daily