ation of that
stick to the opening in the fence. At one time he worked and tugged
three minutes trying to pull the stick through. Of course, if he had
had any mental conception of the problem or had thought about it at
all, a single trial would have convinced him as well as would a dozen
trials. Mr. Morgan tried the experiment with other dogs with like
result. When they did get the stick through, it was always by chance.

It has never been necessary that the dog or his ancestors should know
how to fetch long sticks through a narrow opening in a fence. Hence he
does not know the trick of it. But we have a little bird that knows
the trick. The house wren will carry a twig three inches long through
a hole of half that diameter. She knows how to manage it because the
wren tribe have handled twigs so long in building their nests that
this knowledge has become a family instinct.

What we call the intelligence of animals is limited for the most part
to sense perception and sense memory. We teach them certain things,
train them to do tricks quite beyond the range of their natural
intelligence, not because we enlighten their minds or develop their
reason, but mainly by the force of habit. Through repetition the act
becomes automatic. Who ever saw a trained animal, unless it be the
elephant, do anything that betrayed the least spark of conscious
intelligence? The trained pig, or the trained dog, or the trained lion
does its "stunt" precisely as a machine would do it--without any more
appreciation of what it is doing. The trainer and public performer
find that things must always be done in the same fixed order; any
change, anything unusual, any strange sound, light, color, or
movement, and trouble at once ensues.

I read of a beaver that cut down a tree which was held in such a way
that it did not fall, but simply dropped down the height of the stump.
The beaver cut it off again; again it dropped and refused to fall; he
cut it off a third and a fourth time: still the tree stood. Then he
gave it up. Now, so far as I can see, the only independent
intelligence the animal showed was when it ceased to cut off the tree.
Had it been a complete automaton, it would have gone on cutting--would
it not?--till it made stove-wood of the whole tree. It was confronted
by a new problem, and after a while it took the hint. Of course it did
not understand what was the matter, as you and I would have, but it
evidently concluded that something was