On arriving in tropical regions, this curious fish is seen, and affords some variety to the tedium of a ship; the passengers amusing themselves by watching its flight, and sometimes its “persecution,” when pursued by bonitos, dolphins, albicores, among the finny, and tropic birds, boobies, gannets, &c. among the feathered tribe. I have frequently derived both information and amusement by watching the flight of these fish; to observe them skim the surface of the water for a great distance, sometimes before, and at other times against the direction of the wind, elevating themselves either to a short height from the surface, or to five or six feet, and then, diverging a little from their course, drop suddenly into their proper element; sometimes when their flight was not high above the water, and it blew fresh, they would meet with an elevated wave, which invariably buried them beneath it, but they would often again start from it and renew their flight. I have never yet been able to see any percussion of the pectoral fins during flight, although such a high authority as Cuvier says, “the animal beats the air during the leap, that is, it alternately expands and closes its pectoral fins;” and Dr. Abel also supports this opinion, and says that it agrees with his experience; he has repeatedly seen the motion of the fins during flight, and as flight is only “swimming in air,” it appears natural that those organs should be used in the same manner in both elements. But the structure of a fin is not that of a wing; the pectoral fins or wings of the flying fish are simply enlarged fins, capable of supporting, perhaps, but not of propelling the animal in its flight.[12] In fish, the organ of motion for propelling them through the water is the tail, and the fins direct their course; in birds, on the contrary, the wings are the organs of motion, and the tail the rudder. The only use of the extended pectoral fins in the fish is for the purpose of supporting the animal in the air, like a parachute, after it has leaped from the water by some power, which is possessed by fish of much larger size, even the whale. From the structure of the fin, I cannot consider it at all calculated for repeated percussions out of the water, although while in that fluid it continues its natural action uninjured, as it soon dries when brought into contact with the air, and the delicacy of the membrane between the rays would very readily become injured, were the organ similarly exerted in that medium.