The transition from the ordinary mode of the locomotion of fishes by swimming to that of climbing has been ably illustrated by the Rev. Dr. Buckland, who showed, in a communication to the Ashmolean Society, in 1843, that the fins in certain genera perform the functions of feet and wings. Thus, "fishing-frogs" have the fins converted into feet, or paddles, by means of which they have the power of crawling or hopping on sand and mud; and another species can live three days out of the water, and walk upon dry land. The climbing perch of the Indian rivers is known to live a long time in the air, and to climb up the stems of palm-trees in pursuit of flies, by means of spinous projections on its gill-covers. Fishes of the _silurus_ family have a bony enlargement of the first ray of the pectoral fin, which is also armed with spines; and this is not only an offensive and defensive weapon, but enables the fish to walk along the bottom of the fresh waters which it inhabits. The flying-fishes are notorious examples of the conversion of fins into an organ of movement in the air. M. Deslongchamps has published, in the "Transactions of the Linnæan Society of Normandy," 1842, a curious account of the movements of the gurnard at the bottom of the sea. In 1839, he observed these movements in one of the artificial fishing-ponds, or fishing-traps, surrounded by nets, on the shore of Normandy. He saw a score of gurnards closing their fins against their sides, like the wing of a fly in repose, and without any movement of their tails, walking along the bottom by means of six free rays, three on each pectoral fin, which they placed successively on the ground. They moved rapidly forwards, backwards, to the right and left, groping in all directions with these rays, as if in search of small crabs. Their great heads and bodies seemed to throw hardly any weight on the slender rays, or feet, being suspended in water, and having their weight further diminished by their swimming-bladder. During these movements the gurnards resembled insects moving along the sand. When M. Deslongchamps moved in the water, the fish swam away rapidly to the extremity of the pond; when he stood still, they resumed their ambulatory movement, and came between his legs. On dissection, we find these three anterior rays of the pectoral fins to be supported each with strong muscular apparatus to direct their movements, apart from the muscles that are connected with the smaller rays of the pectoral fin.