The most celebrated example of this faculty, however, is the climbing perch (Anabas scandens) of India. The vagaries of this little fish have been recorded from the earliest times, and numerous modern witnesses have borne record to its powers. Mr E. Layard once encountered several travelling along a hot dusty gravel-road in the mid-day sun.[85] Daldorf, a Danish zoologist of reputation, asserts that he has seen this species in the act of climbing palm-trees, effecting its ascent by means of fins and tail, with the aid of its spinous gill-covers. There is, however, some doubt whether he was not under mistake in this, though the fact of its crawling up the banks and living out of water is abundantly known.
On the coasts of Ceylon, according to its accomplished historian,—on the rocks which are washed by the surf, there are multitudes of a curious little fish, (Salarias alticus,) which possesses the faculty of darting along the surface of the water, and running up the wet stones, with the utmost ease and rapidity. By aid of its pectoral and ventral fins and gill-cases, it moves across the damp sand, ascends the roots of the mangroves, and climbs up the smooth face of the rocks in search of flies; adhering so securely as not to be detached by repeated assaults of the waves. These little creatures are so nimble, that it is almost impossible to lay hold of them, as they scramble to the edge, and plunge into the sea on the slightest attempt to molest them. They are from three to four inches in length, and of a dark-brown colour, almost indistinguishable from the rocks they frequent.[86]
In all these cases probably, the power of sustaining a protracted privation of water depends on a peculiar structure of the pharynx, which is divided by membranous plates into cells which the fish can fill at pleasure with water, and by ejecting small portions at a time can moisten its gills, and thus preserve the filaments of these organs in a fit condition to maintain the circulation and oxygenation of the blood. These labyrinthal water-chambers are particularly numerous and complicated in the Anabas just mentioned. This, however, has no analogy with the lung of the Lepidosiren.