eap
twenty feet high and two hundred yards long; for the flight of the
_Exocetus_ has been observed to be carried to this extent, and even
farther. It is probable that the movement partakes both of the nature
of leaping and flying: that it is first begun by a spring up out of the
water,--a power possessed by most other kinds of fish,--and that the
impulse thus obtained is continued by the spread fins acting on the air
after the fashion of parachutes. It is known that the fish can greatly
lighten the specific gravity of its body by the inflation of its
"swim-bladder," which, when perfectly extended, occupies nearly the
entire cavity of its abdomen. In addition to this, there is a membrane
in the mouth which can be inflated through the gills. These two
reservoirs are capable of containing a considerable volume of air; and
as the fish has the power of filling or emptying them at will, they no
doubt play an important part in the mechanism of its aerial movement.

One thing is certain, that the flying-fish can turn while in the air,--
that is, diverge slightly from the direction first taken; and this would
seem to argue a capacity something more than that of a mere spring or
leap. Besides, the wings make a perceptible noise,--a sort of
rustling,--often distinctly heard; and they have been seen to open and
close while the creature is in the air.

A shoal of flying-fish might easily be mistaken for a flock of white
birds, though their rapid movements, and the glistening sheen of their
scales--especially when the sun is shining--usually disclose their true
character. They are at all times a favourite spectacle, and with all
observers,--the old "salt" who has seen them a thousand times, and the
young sailor on his maiden voyage, who beholds them for the first time
in his life. Many an hour of _ennui_ occurring to the ship-traveller,
as he sits upon the poop, restlessly scanning the monotonous surface of
the sea, has been brought to a cheerful termination by the appearance of
a shoal of flying-fish suddenly sparkling up out of the bosom of the
deep.

The flying-fish appear to be the most persecuted of all creatures. It
is to avoid their enemies under water that they take _fin_ and mount
into the air; but the old proverb, "out of the frying-pan into the
fire," is but too applicable in their case, for in their endeavours to
escape from the jaws of dolphins, albicores, bonitos, and other petty
tyrants of the sea, they rus