of travelling on land, notwithstanding its twofold
respiration; but some of the fishes of the tropics certainly resort to
this mode of evading the fatal contingency of being baked out by the
evaporating power of the periodical dry season.

Theophrastus, the contemporary of Aristotle, mentions fishes found in
the Euphrates which in the dry seasons leave the vacant channels and
crawl over the ground in search of water, moving along by fins and
tail.[81] Pallegoix gives three kinds of fish in Siam, which leave the
tanks and channels and travel through the grass;[82] and Sir John
Bowring states that in ascending the river Meinam to Bangkok, he was
amused with the sight of fish leaving the stream, gliding over the wet
banks, till they disappeared among the trees of the jungle.[83] The
_Hydragyrae_ of Carolina in like manner leave the drying pools, and seek
the nearest water in a straight line, though at a considerable distance.
And Sir R. Schomburgk tells us that certain species of _Dora_ in Guiana
have the same habit, and are occasionally met with in such numbers in
their terrestrial travels that the negroes fill baskets with them.[84]

These fishes, provincially called Hassars, project themselves on their
bony pectoral fins, aiding their advance by the elastic spring of the
tail exerted sidewise, proceeding in this manner nearly as fast as a man
can walk. The strong scaly bands which envelop the body facilitate the
march, in the same way as the transverse plates (_scuta_) on the belly
of serpents, which take hold of the ground, as the ribs perform the
office of feet. The Indians know that these fishes have the power of
carrying a supply of water in a reservoir, for the keeping of the gills
in a moist condition. If they fail in finding water, they are said to
burrow in the still soft mud, and pass the dry season in torpidity like
the _Lepidosiren_.

The common eel is well known to have this habit of travelling with us; I
well remember my surprise, when a boy, at finding an eel in a grassy
meadow one dewy summer evening, at a considerable distance from water.
Since then I have seen a small species of _Antennarius_, running quickly
to and fro on the surface of the great beds of floating sea-weed in the
Gulf stream, progressing by means of its pectorals and ventrals quite
out of water, with the utmost facility.

[Illustration: THE CLIMBING PERCH.]

The most celebrated example of this faculty, however, is the climbing
per