222 THE PHILOSOPHY OF BIRDS NESTS. 



render it certain .that the peculiar notes of birds 

 are acquired by imitation, as surely as a child learns 

 English or French, not by instinct, but by hearing the 

 language spoken by its parents. 



It is especially worthy of remark that, for young 

 birds to acquire a new song correctly, they must be 

 taken out of hearing of their parents very soon, for 

 in the first three or four days they have already 

 acquired some knowledge of the parent notes, which 

 they will afterwards imitate. This shows that very 

 young birds can both hear and remember, and it would 

 be very extraordinary if, after they could see, they 

 could neither observe nor recollect, and could live for 

 days and weeks in a nest and know nothing of its 

 materials and the manner of its construction. During 

 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 



