ere must be no deviation from the rule."
Now we do not see in this fact the way of a thinking or reflecting
being, but rather the way of a creature governed by instinct or
unthinking intelligence. An animal never _learns_ a trick in the sense
that man learns it, never sees through it or comprehends it, has no
image of it in its mind, and no idea of the relations of the parts of
it to one another; it does it by reason of repetition, as a creek
wears its channel, and probably has no more self-knowledge or
self-thought than the creek has. This, I think, is quite contrary to
the popular notion of animal life and mentality, but it is the
conclusion that I, at least, cannot avoid after making a study of the
subject.

II. AN ASTONISHED PORCUPINE

One summer, while three young people and I were spending an afternoon
upon a mountain-top, our dogs treed a porcupine. At my suggestion the
young man climbed the tree--not a large one--to shake the animal down.
I wished to see what the dogs would do with him, and what the
"quill-pig" would do with the dogs. As the climber advanced the
rodent went higher, till the limb he clung to was no larger than one's
wrist. This the young man seized and shook vigorously. I expected to
see the slow, stupid porcupine drop, but he did not. He only tightened
his hold. The climber tightened his hold, too, and shook the harder.
Still the bundle of quills did not come down, and no amount of shaking
could bring it down. Then I handed a long pole up to the climber, and
he tried to punch the animal down. This attack in the rear was
evidently a surprise; it produced an impression different from that of
the shaking. The porcupine struck the pole with his tail, put up the
shield of quills upon his back, and assumed his best attitude of
defense. Still the pole persisted in its persecution, regardless of
the quills; evidently the animal was astonished: he had never had an
experience like this before; he had now met a foe that despised his
terrible quills. Then he began to back rapidly down the tree in the
face of his enemy. The young man's sweetheart stood below, a highly
interested spectator. "Look out, Sam, he's coming down!" "Be quick,
he's gaining on you!" "Hurry, Sam!" Sam came as fast as he could, but
he had to look out for his footing, and his antagonist did not. Still,
he reached the ground first, and his sweetheart breathed more easily.
It looked as if the porcupine reasoned th