Flight v. Glide

With all the science of 5,000 years of civilization at his command, a Connecticut geology professor last week was puzzled by a problem which intrigued ancient Ulysses. Ulysses watched the slim dark fishes dart from the Mediterranean, spread their big fins, and shoot through the air 25 to 30 m.p.h. for as long as 13 seconds, just as Magellan watched them, just as U. S. holiday voyagers on cruises to Havana and Caribbean ports watch them. But do they fly or glide?

A flying fish has big pectoral fins which fold against its sides when the fish swims and spread like the. wings of an airplane when the fish is in the air (see cut). With wings folded, flying fishes' scull themselves rapidly to the surface with their big tail fins and then shoot out into the air at a low angle. The instant their wings are clear of the water they unfold. What the fish do with their wings next seems to be any observer's guess. If the fins flap or flutter, the fish may be said to fly. If the fish hold their outspread fins stiffly, they may be said simply to glide.

Most positive proponent of the gliding theory is University of Michigan's Ichthyologist Carl Leavitt Hubbs, who published his observations in the annual report of the Smithsonian Institution for 1935. He testified that "flying fishes gain the momentum to get into the air with their rigid wings by a surface taxi of from 5 to 15 yards at a speed of about 10 yards a second, comparable to the speed of the best sprinters. This speed is attained by a sculling action of the tail fin. . . . To attain, the speed necessary to get into the air, an average of 50 to 70 complete or double vibrations [of the tail fin] a second are necessary."

Recently, Professor Edward Leffingwell Troxell of Hartford, Conn.'s Trinity College traveled through the tropical Pacific. Although a geologist, he took the trip largely for the purpose of observing "animal adaptation and behavior." Watching for natural phenomena, he studied the appearance of the water just before a flying fish lifted from it. This, said he in Science last week, "was not like the wake of a boat, nor like the ruffled water behind an aeroplane taking off. It was rather a series of dots in two parallel rows, thus : : : : : : :, and was undoubtedly made by the tips of the fluttering wings before the fish had completely cleared the water." The fish, he said, moved close to the water surface, covered up to 50 yards in a flight, would sometimes make "a slight turn of some 20 degrees or so . . . to the left or to the right, and in each case the flight continued at what appeared to be uniform speed. Sometimes a short flight might"be renewed. One seemed to see the wings extended at an angle upward in a fluttering blur of movement."

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