hey would by swimming
hither and thither at terrific speed beneath the silver armour of the
ice.

One night, however, there came to the pond an enemy of whose powers
they had never had experience. Wandering down from northwestward,
under the impulse of one of those migratory whims which sometimes give
the lie to statistics and tradition, came a sinister, dark,
slow-moving beast whose savage and crafty eyes took on a sudden flame
when they detected the white mound which hid the shore beaver-house.
The wolverene did not need that faint, almost invisible wisp of vapour
from the air-holes to tell him there were beavers below. He knew
something about beavers. His powerful forearms and mighty claws got
him to the bottom of the snow in a few seconds. Other hungry marauders
had done the same thing before, to find themselves as far off as ever
from their aim. But the wolverene was not to be balked so easily. His
cunning nose found the minute openings of the air-holes; and by
digging his claws into these little apertures he was able to put forth
his great strength and tear up some tiny fragments of frozen mud.

[Illustration: "A SINISTER, DARK, SLOW-MOVING BEAST."]

If he had had the patience to keep on at his strenuous task
unremittingly for, perhaps, twenty-four hours or more, it is
conceivable that this fierce digger might have succeeded in making his
way into the chamber. There was no such implacable purpose, however,
in his attack. In a very little while he would have desisted from what
he knew to be a vain undertaking. Even had he succeeded, the beavers
would have fled before he could reach them, and taken refuge in their
burrows under the bank. But while he was still engrossed, perhaps only
amusing himself with the thought of giving the dwellers in the house a
bad quarter of an hour, it chanced that a huge lynx came stealing
along through the shadows of the trees, which lay blue and spectral in
the white moonlight. He saw the hind quarters of some unknown animal
which was busy working out a problem which he himself had striven in
vain to solve. The strange animal was plainly smaller than himself.
Moreover, he was in a position to be taken at a disadvantage. Both
these points weighed with the lynx; and he was enraged at this
attempted poaching upon what he chose to regard as his preserves.
Creeping stealthily, stealthily forward, eyes aflame and belly to the
snow, he sprang with a huge bound that landed him, claws open,