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137. Colymbus torquatus Brün. (Northern diver).-Occasional along the rivers.

138. Podiceps californicus Her. (California grebe) --I saw an example that I referred to this species.

139. Podiceps clarki Lawr. (Clarke's grebe).-Occasional along

the rivers.

140. Podilymbus podiceps L. (dabchick).—More common than

the last.

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DO FLYING FISH FLY?

BY C. O. WHITMAN.

F all the modes of animal locomotion, none has excited more general attention than that of flying creatures; and this is none the less so now that many of those who believe in the ultimate success of "the flying machine," have discarded the balloon theory, and come to regard nature's contrivances for flight as the true models for aërial locomotives. Among those animals that enjoy the much envied power of flight, none has elicited such universal interest and comment, from old and young, layman and scientist, as that anomalous member of the finny tribe, the flying fish. Science, poetry and fable have conspired to extend the fame of this little denizen of tropical seas, and philosophy has more than once attempted to find some adequate cause for the enormous development of its pectoral limbs, hoping to find here one more important link between swimming and flying animals.

This fish owes its generic name to a curious belief which is said to have been current among the ancients. They supposed that the flying fish" sea swallows" they called them-left the ocean at night and slept on shore, to avoid the attacks of their marine enemies. From this habit of "sleeping out," they were 'called Exocati.

Besides Exocœtus, which includes between forty and fifty different species, there is a genus of flying fish called Dactylopterus (finger-winged), from the fact that the fin rays extend, finger-like, beyond the margin of the fins. This genus, popularly named the flying gurnard, is represented by comparatively few species which inhabit the Atlantic, the Mediterranean sea, the Indian ocean and archipelago, and the Japan seas.

To those who may never have had the opportunity to observe

the flight of these fishes, it may seem a matter of no little surprise that it is still an unsettled question whether they fly or skim. The difference of opinion on this point is all the more remarkable as the flying fish has been known, at least, since the time of Pliny, and even of Aristotle, and has always attracted the attention of voyagers. Although its aërial flight, to accomplish which it has to leave its native element, is not at all more remark able than the sub-aquatic flight of the quillemots, grebes, auks and penguins, all of which are accustomed to exchange temporarily their own element for that of the finny race, to move through the water with even greater rapidity than the fishes themselves, and to remain submerged longer than the flying fish remains above water; and although the modification of the fins for aërial locomotion is certainly not greater than that of the wings of the auks and penguins for flight under water; yet the testimony of able scientific witnesses, in favor of the actual flight of Exocœtus, has been often challenged by equally good observers, and plausible reasons have recently been urged against even the possibility of such flight.

It is maintained by many, perhaps the majority of observers, that the Exocoti are sustained by the parachute-like action of the pectoral fins, which they simply hold outstretched during their passage through the air. According to this view the fins exhibit none of that "poetry of motion" seen in the bird's wing, being capable of only a passive kite-like action, like the membranewings of the flying squirrel (Pteromys), the flying lemur (Galcopithecus), the marsupial Petaurists (Petaurus Shaw.) or the footweb of the flying frog of Borneo.1

In one of our popular "natural histories" the flight of the flying fish is explained in the following manner: "These fishes possess the power of darting from the water into the air, and by the mingled force of the impetus with which they spring from the surface and the widely spread wing-like fins, to sustain themselves for a short space in the thinner element, and usurp for a time the privileges of the winged beings whose trackless path is through the air."

"The passage of this fish through the atmosphere can lay no just claim to the title of flight, for the creature does not Aap the wing-like pectoral fins on which it is upborne."2

1Described by Wallace in his "Malay Archipelago."

2 Wood's "Natural History."

The following statement to the same effect is found in "The Ocean World," by Louis Figuier: "Their fins sustain them rather as parachutes than wings."

In Beeton's "Dictionary of Natural History," the author speaks thus: "Although some few naturalists have supposed that these fish possess the true power of flying, that is, by beating the air with their members, it is generally agreed that their large fins sustain them parachute-wise when they have leapt from the water."

In the same place occurs a quotation from Bennett's "Wanderings in New South Wales," which is here given in full, as it contains some statements which have found quite general acceptance among scientific men.

Mr. Bennett says, "I have never been able to see any percussion of the pectoral fins during flight, and the greatest length of time that I have seen this fish on the fin has been thirty seconds by the watch; and the longest flight mentioned by Capt. Hall1 is two hundred yards; but he thinks that subsequent observation has extended the space. The most usual height of flight, as seen above the surface of the water, is from two to three feet; but I have known them come on board a ship at a height of fourteen feet; and they have been well ascertained to have come into the channels of a man-of-war, which is considered as high as twenty feet and upwards. But it must not be supposed they have the power of elevating themselves after leaving their native element; for on watching them, I have often seen them fall much below the elevation at which they first rose from the water, but never in any one instance could I observe them rise from the height at which they first sprang; for I regard the elevation they take to depend on the power of the first spring or leap they make on leaving their native element."

Burmeister in his "Reise nach Brasilien " (Berlin, 1853, p. 36), declares that he watched the flying fish for a long time, and saw, with certainty, "that they made no kind of movement with their large pectoral fins, but held them quietly outspread like a parachute."

In his well-known work on "Animal Locomotion " (p. 98), Pettigrew says: "Whether the flying fish uses its greatly expanded pectoral fins as a bird its wings, or only as parachutes, 1 "Lieutenant and Commander," by Capt. Basil Hall.

has not, so far as I am aware, been determined by actual observation. Most observers are of opinion that these singular creatures glide up the wind, and do not beat it after the manner of birds; so that their flight (or rather leap) is indicated by the arc of a circle, the sea supplying the chord."

From a careful examination of the structure and action of these fins, Pettigrew has been able to satisfy himself that "they act as true pinions within certain limits." That this restrictive phrase, "within certain limits," is intended to exclude a flapping motion, is evident from the following: "The flapping and gliding action of the wings constitute the difference between ordinary flight and that known as skimming or sailing flight. The flight of the flying fish is to be regarded rather as an example of the latter than the former, the fish transferring the velocity acquired by the vigorous lashing of its tail in the water to the air."

Pettigrew shows that all kinds of wings, when extended in flight, have a kite-like action, or a "combined parachute and wedge action" independent of any beating movement; and it is to this action alone that he refers when he says the pectorals "act as true pinions within certain limits."

According to Pettigrew, "Mr. Swainson, in crossing the line in 1816, zealously attempted to discover the true action of the fins in question; but the flight of the fish is so rapid that he utterly failed." So much for the negative testimony.

In favor of the flapping motion of these fins, we have the testimony of Capt. de Freminville,' who says, "I have been able to convince myself that they [flying fish] do actually fly, impressing upon their fins, which serve them as wings, a rapid movement—a species of vibration [frémissement]-which sustains them and causes them to advance through the air."

Speaking of these fish, which he saw on the way from Callao to Lima, U. de Tessan2 says: "J'ai très-bien vu un poissonvolant battre d'abord des ailes en l'air, et puis les faire vibrer en planant."

In the "Reise der Oesterreichischen Fregatte Novara um die Erde" (1857-1859), published by Wüllerstorf-Urbair, 1861, p. 109, occurs (according to Möbius) the following: "Careful ob1 Ann. des Sci. Nat., Vol. XXI, p. 102, 1830.

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servation enables one to see that the wing-like pectoral fins of the flying fish are capable of a vibrating movement, like the wings of a grasshopper."

Dr. Kneeland' makes the following noteworthy statements as the result of observations made in 1870, on a voyage from San Francisco to Panama: "The ventrals were expanded like the pectorals in the act of flight. They rose out of a perfectly smooth sea, showing that they are not mere skippers from the top of one wave to another; they could be seen to change their course as well as to rise and fall, not unfrequently touching the longer, lower lobe of the tail to the surface, and again rising, as if they used the tail as a powerful spring. While the ventrals may have acted chiefly as a parachute, it seemed that the pectorals performed, by their almost imperceptible but rapid vibrations, the function of true flight."

To the same effect speaks A. v. Humboldt2 when he says, "Notwithstanding the astonishing swiftness of their movement, one can convince oneself that the animal beats the air during its spring, i. e., that it alternately opens and closes its pectoral fins."

In his work "On the Origin of Species" (p. 175), the great naturalist remarks: "It is conceivable that flying fish, which now glide far through the air, slightly rising and turning by the aid of their fluttering fins, might have been modified into perfectly winged animals. If this had been effected, who would have ever imagined that in an early transitional state they had been the inhabitants of the open ocean, and had used their incipient organs of flight exclusively, as far as we know, to escape being devoured by other fish ?"

Without attempting to make this bibliographic sketch exhaustive—an infeasible undertaking with the libraries at my command -I will now pass to my own observations on the flight of flying fish, made during a voyage from San Francisco to Yokohama, on the steamer City of Peking, reserving till the last the consideration of the recent elaborate paper of Prof. Carl Möbius.3

Of the nearly twenty-three days that elapsed between departure and arrival (Aug. I to Aug. 24, 1879), at least ten were favorable for the study of the question under consideration.

1 Proceed. Boston Soc. Nat. Hist., Vol. XIV, p. 138, 1872.

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2" Reise in die Aequinoctial-Gegenden des neuen Continents," 1, Stuttgart, 1815. 'Die Bewegungen der fliegenden Fische durch die Luft." Zeitschrift für Wissenschaftliche Zoologie, Supplement to Vol, xxx, p. 343, 1878.

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