40 THE ZOOLOGIST. 



almost horizontal direction." That is a quite possible explanation of 

 the mode of flight, provided that a sufficient speed be acquired in the 

 intermediate flappings, but this the known speed of the fish shows to 

 be not commonly the case. 



Again, on p. 148 : "I am perfectly well aware that a casual glance 

 at Flying-fish from the lofty deck of a liner gives the impression that 

 they soar like birds with motionless wings, but watch them at close 

 quarters from the deck of a low-waisted tramp, and the vibratory 

 motion of the tail and fins will be quite plain." 



Interesting as is Mr. Adams's paper, I cannot but think that he is 

 partly mistaken in his views, and that the wing- vibration which he 

 discerned was really less rapid than the movement in the period follow- 

 ing which he believed to be one of stillness, just as the liner-passengers 

 mistook his vibrations for stillness. I do not say that the fish could 

 never arrive at a speed by which a very short aeroplane flight could be 

 attained even with their low ratio ; but I do say that such is not their 

 common speed, and that in any case their disregard of wind-direction 

 disproves such flight. Therefore another way must be looked for, and 

 we are driven back, perforce, to continuous wing-action, the manner of 

 which may be here examined as carefully as our information allows. 



Premising that the flight varies greatly on different days and under 

 different conditions, the following is probably a fair description of their 

 methods in an ordinary flight : — 



1. The tail-impelled, visibly (to many) wing-assisted jump from the 

 water to a height where the wings can work freely. 



2. The flight continued by an intensely rapid and laboured wing- 

 movement — one easily mistaken for stillness, and usually seen, if at all, 

 as blurr. 



3. Short periods of slowing down of wing-speed, during which the 

 wing-movement becomes again visible. (These are the "vibration" 

 periods, representing to aeroplanists loose wing-trailing, or dragging 

 like a flapping flag — an impossibility ; and, to Mr. Adams, periods of 

 wing-assistance — with limitations a possibility.) These periods often 

 precede a special spurt such as is required to lift the fish over an on- 



coming wave. 



4. Either sudden cessation of wing-movement and consequent im- 

 mediate drop into the sea, or a short slow down into visibility (No. 3) 

 previous to such drop. 



It is to be noted that this vibration so often seen before the fish 

 enters the water is one of the many pointers to continuous wing- 

 movement, for such a time is a proper one for slowing down, but an 

 absurd one for renewal of wing-effort. 



