WAYS OF NATURE 
cess of trial and failure. Man also achieves many 
things through practice alone, or through the same 
process of trial and failure. Much of his manual 
skill comes in this way, but he learns certain things 
through the exercise of his reason; he sees how the 
thing is done, and the relation of the elements of the 
problem to one another. The trained animal never 
sees how the thing is done, it simply does it auto- 
matically, because certain sense impressions have 
been stamped upon it till a habit has been formed, 
just as a man will often wind his watch before going 
to bed, or do some other accustomed act, without 
thinking of it. 
The bird builds her nest and builds it intelli- 
gently, that is, she adapts means to an end; but 
there is no reason to suppose that she thinks about 
it in the sense that man does when he builds his 
house. The nest-building instinct is stimulated into 
activity by outward conditions of place and climate 
and food supply as truly as the growth of a plant is 
thus stimulated. 
As I look upon the matter, the most wonderful 
and ingenious nests in the world, as those of the 
weaver-birds and orioles, show no more independent 
self-directed and self-originated thought than does 
the rude nest of the pigeon or the cuckoo. They 
evince a higher grade of intelligent instinct, and that 
is all. Both are equally the result of natural prompt- 
ings, and not of acquired skill, or the lack of it. One 
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