off some
hours, it returned in company with three yellowtails, a sort of cousin
to the dolphin. This little school kept together, except when in
danger and when foraging about the sea. Their lives were often
threatened by hungry sharks that came round the vessel, and more than
once they had narrow escapes. Their mode of escape interested me
greatly, and I passed hours watching them. They would dart away, each
in a different direction, so that the wolf of the sea, the shark,
pursuing one, would be led away from the others; then after a while
they would all return and rendezvous under one side or the other of
the sloop. Twice their pursuers were diverted by a tin pan, which I
towed astern of the sloop, and which was mistaken for a bright fish;
and while turning, in the peculiar way that sharks have when about to
devour their prey, I shot them through the head.

Their precarious life seemed to concern the yellowtails very little,
if at all. All living beings, without doubt, are afraid of death.
Nevertheless, some of the species I saw huddle together as though they
knew they were created for the larger fishes, and wished to give the
least possible trouble to their captors. I have seen, on the other
hand, whales swimming in a circle around a school of herrings, and
with mighty exertion "bunching" them together in a whirlpool set in
motion by their flukes, and when the small fry were all whirled nicely
together, one or the other of the leviathans, lunging through the
center with open jaws, take in a boat-load or so at a single mouthful.
Off the Cape of Good Hope I saw schools of sardines or other small
fish being treated in this way by great numbers of cavally-fish. There
was not the slightest chance of escape for the sardines, while the
cavally circled round and round, feeding from the edge of the mass. It
was interesting to note how rapidly the small fry disappeared; and
though it was repeated before my eyes over and over, I could hardly
perceive the capture of a single sardine, so dexterously was it done.

Along the equatorial limit of the southeast trade winds the air was
heavily charged with electricity, and there was much thunder and
lightning. It was hereabout I remembered that, a few years before, the
American ship _Alert_ was destroyed by lightning. Her people, by
wonderful good fortune, were rescued on the same day and brought to
Pernambuco, where I then met them.

On September 25, in the latitude of 5 degrees N.