iscouraged, and, after making several feints to cross, one of them
seized the wounded one and bore it over, and the pack disappeared in the
wall on the other side.

Let me conclude this chapter with two or three more notes about this
alert enemy of the birds and lesser animals, the weasel.

A farmer one day heard a queer growling sound in the grass: on
approaching the spot he saw two weasels contending over a mouse; both
held the mouse, pulling in opposite directions, and they were so
absorbed in the struggle that the farmer cautiously put his hands down
and grabbed them both by the back of the neck. He put them in a cage,
and offered them bread and other food. This they refused to eat, but in
a few days one of them had eaten the other up, picking his bones clean,
and leaving nothing but the skeleton.

The same farmer was one day in his cellar when two rats came out of a
hole near him in great haste, and ran up the cellar wall and along its
top till they came to a floor timber that stopped their progress, when
they turned at bay, and looked excitedly back along the course they had
come. In a moment a weasel, evidently in hot pursuit of them, came out
of the hole, but, seeing the farmer, checked his course and darted back.
The rats had doubtless turned to give him fight, and would probably have
been a match for him.

The weasel seems to track its game by scent. A hunter of my acquaintance
was one day sitting in the woods, when he saw a red squirrel run with
great speed up a tree near him, and out upon a long branch, from which
he leaped to some rocks, disappearing beneath them. In a moment a weasel
came in full course upon his trail, ran up the tree, then out along the
branch, leaping from there to the rocks just as the squirrel had done
and pursuing him into their recesses.

Doubtless the squirrel fell a prey to him. The squirrel's best game
would have been to keep to the higher treetops, where he could easily
have distanced the weasel. But beneath the rocks he stood a very poor
chance. I have often wondered what keeps such an animal as the weasel in
check, for they are quite rare. They never need go hungry, for rats and
squirrels and mice and birds are everywhere. They probably do not fall
a prey to any other animal, and they are very rarely captured or killed
by man. But the circumstances or agencies that check the increase of any
species of animal are, as Darwin says, very obscure and but little
known.