120 THE STORY OF LIFE IN THE SEAS. 



It is difficult to give any general features by 

 which they are characterised, as so much variety 

 may be observed among them ; but as a general 

 rule they are elongated in form, round or oval 

 in section, in colour green or gray above, with 

 silvery white bellies. Some of these, such as 

 the Flying-fish and the Flying-gurnard, are 

 capable of making very considerable flights in 

 the air, their pectoral fins being enormously 

 elongated, and when fully expanded somewhat 

 similar to the wing of an Insect. / 



The Flying-fish occur in shoals in nearly 

 all tropical and subtropical seas. When dis- 

 turbed by a ship on a calm day it is said that 

 they spring out of the sea, expand their fins, 

 describe a regular parabolic curve in the air, and 

 then fall with a splash into the water. There is 

 a considerable controversy raging on the question 

 of the use of their fins in this flight through the 

 air, some observers believing that the fins are 

 used only as a kind of parachute, and others that 

 they are used like wings for raising the body 

 above the water. It is very difficult to decide 

 which view is correct. 



In the Indian Ocean I watched the Flying-fish 

 for several days during rather rough weather, 

 and my impression was most distinctly that in 

 the middle of the flight the fins are vigorously 

 flapped four or five times, the flapping being 

 followed by a decided rise in the air. On the 

 other hand, it may be that this flapping ap- 

 pearance is caused by the wind catching the 

 wings in a certain position, and not by the 

 muscles of the fish. Whether the flying is 



