alder brooks of a whole wild
countryside he wanders without rest, stopping here and there on a
grassy point to gather a little handful of mud, like a child's mud
pie, all patted smooth, in the midst of which is a little strong
smelling musk. When you find that sign, in a circle of carefully
trimmed grass under the alders, you know that there is a young beaver
on that stream looking for a wife. And when the young beaver finds his
pie opened and closed again, he knows that there is a mate there
somewhere waiting for him. But the poor bank beaver never finds his
mate, and the next winter must go back to his solitary den. He is much
more easily caught than other beavers, and the trappers say it is
because he is lonely and tired of life.

The second theory is that generally held by Indians. They say the bank
beaver is lazy and refuses to work with the others; so they drive him
out. When beavers are busy they are very busy, and tolerate no
loafing. Perhaps he even tries to persuade them that all their work is
unnecessary, and so shares the fate of reformers in general.

While examining the den of a bank beaver last summer another theory
suggested itself. Is not this one of the rare animals in which all the
instincts of his kind are lacking? He does not build because he has no
impulse to build; he does not know how. So he represents what the
beaver was, thousands of years ago, before he learned how to construct
his dam and house, reappearing now by some strange freak of heredity,
and finding himself wofully out of place and time. The other beavers
drive him away because all gregarious animals and birds have a strong
fear and dislike of any irregularity in their kind. Even when the
peculiarity is slight--a wound, or a deformity--they drive the poor
victim from their midst remorselessly. It is a cruel instinct, but
part of one of the oldest in creation, the instinct which preserves
the species. This explains why the bank beaver never finds a mate;
none of the beavers will have anything to do with him.

This occasional lack of instinct is not peculiar to the beavers. Now
and then a bird is hatched here in the North that has no impulse to
migrate. He cries after his departing comrades, but never follows. So
he remains and is lost in the storms of winter.

There are few creatures in the wilderness more difficult to observe
than the beavers, both on account of their extreme shyness and because
they work only by night. The best w