i 82 
NATURE NOTES. 
in animals, says, very definitely, that “ the singing of birds is 
certainly instinctive.” Another is of opinion that “ notes in 
birds are no more innate than language is in man, and depend 
entirely on the master under which they are bred, as far as their 
organs will enable them to imitate the sounds which they have 
frequent opportunities of hearing.” Between these two dia- 
metrically opposite opinions we find every intermediate view 
displayed and advocated. The experiments that have been 
made to test these opinions differ almost as widely in their 
results as the views themselves ; thus, on this subject, we are 
entirely left to form our own views. 
A consideration of all the circumstances may, perhaps, lead 
us to the conclusion that instinct may be best regarded as a 
plastic faculty ; and that any particular action that we may 
consider may be looked upon as resulting in part from instinct, 
and in part from intelligence or reason. The sparrows used 
originally, no doubt, to build their nests in trees, and then, in 
order to be secure, they had to pay attention to structure ; but 
when, by and by, they had learnt to make their nests in the 
corners of house-roofs, they soon found that they could save 
themselves a lot of trouble in construction by building their nest 
as loosely as ever they liked. And this saving of trouble in 
nest-building is one of the things that birds seem to learn the 
readiest of all. Some young chaffinches were once taken very 
early out of the nest, carried to New Zealand, and there turned 
out. At home, we know they build some of the loveliest of all 
nests; but in New Zealand they built a loose nest lined with 
feathers, in the fork of a tree, wherefrom it hung down a foot 
from the side of a supporting branch, thus forming a nest totally 
different from the compact structure that they always make in 
England. They had there probably imitated the nest of some 
New Zealand species. Such an experience as this would seem to 
show that birds do not make their nests by blind instinct, but by 
imitating some nest that they have seen near them. 
If instinct means anything definite, it must mean the capacity 
to perform complex acts without teaching or experience ; thus 
such a pretty piece of work as a chaffinch’s nest we might surely 
expect to be done, if done by this faculty, in the same way in 
whatever part of the world it is constructed. On whichever side 
we approach the subject, it is beset with difficulties. We can 
see quite surely that birds le.arn much as time passes on. Since 
the invention of churches, jackdaws have, as we well know, got 
fond of the steeple. House and chimney swallows must have 
largely changed their habits and modes of building since the 
multiplication of the houses in which they love to take up their 
abode. This leads us to inquire whether there is much, if any, 
difference between the faculties exhibited by birds in building 
nests, and those shown by man in constructing his own dwellings ; 
the phenomena presented in the several cases seeming to indicate 
no essential difference in the kind or nature of the mental 
