THE PHILOSOPHY OF BIRDS’ NESTS. 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? Would it not be much more remark- 
able 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 cele- 
rity 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 Jefore 
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 ma- 
terials would come in their way during their daily 
