But certain fishes are known, not merely to live when taken out of water, but actually of themselves, and as part of their life and habits, to voluntarily leave the water, and disport themselves on land. Of such abnormal fishes, the most famous is the Climbing Perch or _Anabas scandens_ of India, which inhabits the Ganges, and is also found in Asiatic ponds and lakes. These fishes may be seen to leave the water, and to make their way overland, supporting themselves in their jerking gait by means of their strong spiny fins. They appear to migrate from one pool to another in search of 'pastures new,' especially in the dry season, and when the water of their habitats becomes shallow. The Hindu names applied to these fishes mean 'climbers of trees;' and although statements have been made both by travellers and natives, that the Climbing Perch has been found scaling the stems of trees, these accounts, we fear, must be regarded as of equal value with the native belief that the fishes fall in showers on the land 'from the skies!' Of the power of the fishes to live for five or six days out of water, however, no doubt can be entertained; and their ability to support life under these unwonted conditions, is explained by the fact that certain bones of the head are curiously contorted so as to form a labyrinth, amid the delicate recesses of which a supply of water is retained, for the purpose of keeping the gills moist. The curious _Lepidosirens_ or Mudfishes, which occur in the Gambia of Africa and the Amazon of South America, exhibit a greater peculiarity of structure which still more completely fits them for living out of water. In the great majority of fishes, a curious sac or bag known as the _swimming_ or _air bladder_ is found. The use of this structure in ordinary fishes is to alter the specific gravity of the animals; and, by the compression or expansion of the air or gases it contains, to enable them to sink or rise in the water at will. In the Mudfishes, however, the air-bladder becomes divided externally into two sacs, whilst internally each division exhibits a cellular structure resembling that seen in the lungs of higher animals. Then also, this elaborate air-bladder communicates with the mouth and throat by a tube, which corresponds to a windpipe. The nostrils of the Mudfishes further open backwards into the mouth; whilst in all other fishes, except in one genus, the nostrils are simple, closed, pocket-like cavities. And it may lastly be noted that the _Lepidosirens_ are provided with true gills, like their ordinary and more commonplace neighbours.