Gold Fish (of the Carp family) have been made to distinguish a particular sound made by those from whom they receive their food; they recognise their footsteps at a distance, and come at their call. Captain Brown says Gold Fish, when kept in ponds, are "frequently taught to rise to the surface of the water at the sound of a bell to be fed;" and Mr. Jesse was assured that Gold Fish evince much pleasure on being whistled to. Hakewill, in his "Apology for God's Power and Providence," cites Pliny to show that a certain emperor had ponds containing fish, which, when called by their respective _names_ that were bestowed upon them, came to the spot whence the voice proceeded. Bernier, in his "History of Hindustan," states a like circumstance of the fish belonging to the Great Mogul. The old poet, Martial, also mentions fish coming at the call, as will be seen by the following translation from one of his epigrams:-- "Angler! could'st thou be guiltless? Then forbear: For these are sacred fishes that swim here; Who know their Sovereign, and will lick his hand. Than which none's greater in the world's command; Nay, more; they've names, and when they called are. Do to their several owners' call repair." Who, after reading so many instances, can doubt that fish hear? It has been found that the water from steam-engines, which is thrown into dams or ponds for the purpose of being cooled, conduces much to the nutriment of Gold Fish. In these dams, the average temperature of which is about eighty degrees, it is common to keep Gold Fish; in which situation they multiply much more rapidly than in ponds of lower temperature exposed to variations of the climate. Three pair of fish were put into one of these dams, where they increased so rapidly that at the end of three years their progeny, which was accidentally poisoned by verdigris mixed with the refuse tallow from the engine, were taken out by wheel-barrow-fuls. Gold Fish are by no means useless inhabitants of these dams, as they consume the refuse grease which would otherwise impede the cooling of the water by accumulating on its surface. It is not improbable that this unusual supply of aliment may co-operate with increase of temperature in promoting the fecundity of the fishes.