largely on these piranhas. But the tables were readily turned if any
caymans were injured. When a capybara was shot and sank in the water,
the piranhas at once attacked it, and had eaten half the carcass ten
minutes later. But much more extraordinary was the fact that when a
cayman about five feet long was wounded the piranhas attacked and tore
it, and actually drove it out on the bank to face its human foes. The
fish first attacked the wound; then, as the blood maddened them, they
attacked all the soft parts, their terrible teeth cutting out chunks
of tough hide and flesh. Evidently they did not molest either cayman
or capybara while it was unwounded; but blood excited them to frenzy.
Their habits are in some ways inexplicable. We saw men frequently
bathing unmolested; but there are places where this is never safe, and
in any place if a school of the fish appear swimmers are in danger;
and a wounded man or beast is in deadly peril if piranhas are in the
neighborhood. Ordinarily it appears that an unwounded man is attacked
only by accident. Such accidents are rare; but they happen with
sufficient frequency to justify much caution in entering water where
piranhas abound.

We frequently came across ponds tenanted by numbers of capybaras. The
huge, pig-like rodents are said to be shy elsewhere. Here they were
tame. The water was their home and refuge. They usually went ashore to
feed on the grass, and made well-beaten trails in the marsh
immediately around the water; but they must have travelled these at
night, for we never saw them more than a few feet away from the water
in the daytime. Even at midday we often came on them standing beside a
bayou or pond. The dogs would rush wildly at such a standing beast,
which would wait until they were only a few yards off and then dash
into and under the water. The dogs would also run full tilt into the
water, and it was then really funny to see their surprise and