hen the young elvers
come to a weir, a wall, a floodgate, or a lasher, they simply squirm
their way up the perpendicular barrier with indescribable wrigglings, as
if they were wholly unacquainted, physically as well as mentally, with
Newton's magnificent discovery of gravitation. Nothing stops them; they
go wherever water is to be found; and though millions perish hopelessly
in the attempt, millions more survive in the end to attain their goal in
the upper reaches. They even seem to scent ponds or lakes mysteriously,
at a distance, and will strike boldly straight across country, to sheets
of water wholly cut off from communication with the river which forms
their chief highway.

The full-grown eels are also given to journeying across country in a
more sober, sedate, and dignified manner, as becomes fish which have
fully arrived at years, or rather months, of discretion. When the ponds
in which they live dry up in summer, they make in a bee-line for the
nearest sheet of fresh water, whose direction and distance they appear
to know intuitively, through some strange instinctive geographical
faculty. On their way across country, they do not despise the succulent
rat, whom they swallow whole when caught with great gusto. To keep their
gills wet during these excursions, eels have the power of distending the
skin on each side of the neck, just below the head, so as to form a big
pouch or swelling. This pouch they fill with water, to carry a good
supply along with them, until they reach the ponds for which they are
making. It is the pouch alone that enables eels to live so long out of
water under all circumstances, and so incidentally exposes them to the
disagreeable experience of getting skinned alive, which it is to be
feared still forms the fate of most of those that fall into the clutches
of the human species.

A far more singular walking fish than any of these is the odd creature
that rejoices (unfortunately) in the very classical surname of
Periophthalmus, which is, being interpreted, Stare-about. (If he had a
recognised English name of his own, I would gladly give it; but as he
hasn't, and as it is clearly necessary to call him something, I fear we
must stick to the somewhat alarming scientific nomenclature.)
Periophthalmus, then, is an odd fish of the tropical Pacific shores,
with a pair of very distinct forelegs (theoretically described as
modified pectoral fins), and with two goggle eyes, which he can protrude
at pl