^68 DR. E. II. IIAXKIN ON THE 



111 view of these gradual changes in the performances of tlie 

 fishes, there seems to be no room for doubt tliat they wished to 

 get away from the neighbourhood of tlie ship, by air and as 

 quickly as possible, throughout, and that the air was getting 

 progressively less and less fitted for their flight. 



On the other hand, it has been observed by me on many 

 occasions that the air remains suitable for the gliding flight of 

 flying-fishes after sunset if wind is present. 



2. Flight under fully favour ahla atmospheric conditions. 



During the same voyage, in sunshine and in the presence of a 

 light Avind, flying-fishes were seen by me to fly at a, uniform 

 height above the water till they were out of sight. This was 

 noted on two or three occasions. On a previous voyage I had 

 seen a flight till out of sight under cloud in a monsoon wind. A 

 binocular was used for these observations. Usually the longer 

 flights appear to be between 200 and 400 metres in length. In a 

 flight of this kind the following phenomena may be noticed : — 



The fore wings (pectoral fins) are usually in the " flat" position. 

 i. e. extended in the horizontal plane. Sometimes the wings are 

 slightly inclined upwards. In this case the outer part of the 

 wing is at a higher level than its base. This may be called the 

 " up " position. Rarely the wings are inclined veiy slightly 

 downwards. This may be described as the " down " position. 

 This la,tter disposition, which I was only able to see distinctly on 

 my recent voyage, is probably that used for flight at highest 

 speed, as in slow-speed flight the wings are inclined upwards to a 

 strong degree. 



Tlius in respect of its wing-disposition the flying-fish resembles 

 the soaring vulture, for vultures liave their wings in the "up" 

 position for slow-speed flight and use the " flat " wing disposition 

 for flight at high speed. A further resemblance is indicated by 

 the following very unexpected observation : — 



If the flying-fish is very carefully observed the extreme wing- 

 tipSj for nearly an inch of their length, may be seen to be bent 

 up forming an angle of perhaps 45 degrees with the rest of the 

 wing. If the sun is not far above the horizon, and if the fish is 

 travelling away from the observer in a southerly (presumably also 

 in a northei'ly) direction, then the wing-tip furthest from the sun 

 appears thicker than the other. This appeai'ance has been seen 

 by me quite clearly and definitely in flying-fishes of two different 

 "species. The appearance seems to be due to the upturned wing- 

 tip being bent round so that it has a negative angle of incidence 

 and hence, when the sun is low, the underside of one wing-tip is 

 seen in shadow. When the sun gets higher the visibility of each 

 wing-tip is reinforced by shadow in this way. But, at best, the 

 upturned wing-tip is by no means easy to see. 



The bent-up wing-tips show no appearance of vibration. They 

 appear as if held in their position by a steady force. As I have 



