fast by its crushed fibres. On the other side its top branches
were buried under rocks and mud, so as to render them secure. Against
this tree upright stakes rested; and these again were wattled together,
and firmly bedded in rocks that had been collected around their lower
ends. Behind these uprights were piled other stakes and branches laid
crosswise, and bound together with layers of rocks and mud--so that the
whole structure formed a wall of full six feet in thickness--broad along
the top, and sloping off toward the water. On the lower side it stood
nearly perpendicular, as the uprights were thus set. The top of this
was plastered with mud, and at both sides was left a narrow sluice, or
wash, through which the water ran smoothly off, without wearing away the
breastwork.

"I have said that the work bore the marks of design, as much as if it
had been constructed by human hands. But it was not. The builders of
that breastwork were before my eyes, and apparently just resting from
their labours.

"There were about an hundred of them in all, squatting over the ground,
and along the parapet of the new-made dam. They were of a dark-brown,
or rather a chestnut colour; and reminded me of so many gigantic rats--
except that their tails were pot elongated and tapering like these.
Their backs, however, were arched, and their bodies of a thick rounded
shape, similar to animals of the rat kind. Moreover, I could perceive
that they were armed with the cutting teeth, which distinguish the
family of the _rodentia_, or `gnawers.' These teeth I could see
distinctly--as some of the animals were using them at the time, and they
even protruded when their mouths were shut. I noticed that there was a
pair of them in each jaw, broad, strong, and shaped like chisels. The
ears of the animals were short, and almost buried in the hair, which
although long was not shaggy, but presented a smooth appearance over all
parts of their bodies. There was a tuft of stiff bristles growing out
on each side of the nose, like the whiskers of a cat; and their eyes
were small, and set high up, like those of the otter. Their fore limbs
were shorter than the hind ones, and both had feet with five claws, but
the hind feet were broad and large, and completely webbed between the
toes. It was they, then, that had made the tracks I had observed in
coming up the stream. But the most striking feature of these animals
was the tail. This appendage was en