402 
SPINY-FINNED OR 0 UP. 
the pectoral fins. They are further characterised by the blunt and short-jawed 
head, and the moderately long oblong body invested in a coat of rather large-sized 
scales; the teeth, when present at all, being minute or rudimental. The ordinary 
length of a flying-fish is from 10 inches to a foot, although specimens are 
occasionally met with half as long again; and whereas the common form ranges 
round the world, the distribution of some other species is extremely restricted, one 
being recorded only from the seas on the Pacific side of the Isthmus of Panama. 
The species differ considerably in the length of the pectoral fins; those in which 
they reach to the tail-fin being capable of taking the longest flights, whereas in 
some others they do not extend beyond the anal. Associating in shoals, which are 
sometimes of immense size, all these fish are pelagic in their habits, and all are 
capable of taking the skimming flight from which they derive their name. That 
these fish take their flights primarily to escape from their enemies may be regarded 
as certain; and it is equally well ascertained that the continuance of the flight is 
due to the original impetus of the leap from the water, and is not prolonged by 
any flapping of the fins. From my own observations I am, however, of opinion 
that the pectoral fins are vibrated rapidly on first leaving the water for a few 
seconds, doubtless from a continuation of the swimming motion while in the 
water, after which they become entirely motionless. During flight, the colour of 
these fins may appear either white or brown, when seen from above, according to 
the incidence of the light. So far as I have seen, flying-fish are unable to change 
the direction of their course to any marked extent; but on this point, as will be 
seen from the two following accounts, there is some difference of opinion among 
observers. The first of these two accounts is abridged by Dr. Gunther from one 
published by Dr. Mobias, and runs as follows: “ Flying-fish are more frequently 
observed in rough weather and in a disturbed sea than during calms; they dart 
out of the water when pursued by their enemies, or frightened by an approaching 
vessel, but frequently also without any apparent cause, as is also observed in many 
other fishes; and they rise without any regard to the direction of the wind or 
waves. The fins are kept quietly distended, without any motion, except an 
occasional vibration caused by the air whenever the surface of the wing is parallel 
with the course of the wind. Their flight is rapid, but gradually decreasing in 
velocity, greatly exceeding that of a ship going ten miles an hour, and extending 
to a distance of five hundred feet. Generally, it is longer when the fish fly against 
than with, or at angle to the wind. Any vertical or horizontal deviation from a 
straight line is not caused at the will of the fish, but by currents of the air; the 
fish retaining a horizontally straight course when flying with or against the wind, 
but being carried to one side whenever the direction of the latter is at an angle to 
that of their flight. It may, however, happen that in the course of its flight a fish 
may dip its tail in the crest of a wave, thus changing its direction to the left or 
right. In calm weather the line of flight is always also vertically straight, or 
rather parabolic, like the course of a projectile, but in a rough sea, when the fish 
are flying against the course of the waves, it may become undulating. In such 
instances the flying-fish frequently overtop each wave, being carried over by the 
pressure of the disturbed air. Flying-fish often fall on board vessels, but this 
never happens during a calm, or from the lee-side, always taking place in a breeze 
