FLIGHT OF FLYING-FISHES. 



473 



their greatest extent, thus offering the inaximum resistance to 

 speed ahead. On one occasion the adjacent edges of the two 

 hind wings appeared to me to overlap. Ahnost or quite simul- 

 taneonsly witli the full rotation of the hind wings, the tail is 

 lowered and the fore wings are placed in the op position. The 

 tail then touches the water, and the fish falls in with practically 

 no splash. 



Text-figure 2. 



A, Flying-fish in low-speed flight. 



B. Hind wings advanced at end of flight. 



In monsoon winds the fish may place its hind wings in the 

 down position and even rotate them almost from the commence- 

 ment of its flight. If this is done no high apparent speed is 

 attained even in cases in which the fish is travelling at right 

 angles to the wind. 



Much practice in observing flying-fishes was needed by me 

 before it was possible to see these adjustments of the hind 

 wings. On my last voyage, in June 1920, I was able to see 

 clearly the full rotation of the hind wings in flying-fishes of three 

 different species. 



6. Method of checking speed in sloio-speed flight. 



If the flying-fish is making a flight at slow speed, as happens 

 more frequent!}^ in the colder than in the hotter months of the 

 year, and as happens usually in the absence of wind, an entirely 

 different means of checking speed is employed and one which is 

 much more easy to observe. 



During slow flight the fore wings are strongly inclined up and 

 the tail hangs down. The hind wings, as in high-speed flight, 



Proc. Zool. Soc— 1920, No. XXXII. ^ 32 



