498 FLYING FISHES AND THEIR HABITS. 



the Pacific coast of America, and C. gibhifrons and C. cyanopterus 

 from the Atlantic. The others enjoy a wide range and most are 

 found both in the Athmtic and Pacific. 



There is a notable uniformit}^ in size for so large a group, the 

 extremes for full-groAvn of different species being near 8 inches at 

 one extremity and 18 at the other. About a foot is near the average 

 and a foot and a half appears to be the usual length of the full-grown 

 Californian flying fish {Cypselurus caUfornicus), and sometimes at 

 least attained by several others. 



All are gregarious and keep quite close together in large — sometimes 

 very large — schools. They often swim at or ver}'^ near the surface of 

 the "vvater, with the pectoral and ventral fins pressed close to the body, 

 or at least not far divergent from the sides and below, and are pro- 

 pelled '* by rapid, long, sweeping strokes of the tail and i^osterior 

 half of the body." But every now and then the pectoral fin on one 

 side is slowly expanded to its full extent for the purpose, it appears, 

 of simply stretching them for exercise, as they swim on without 

 turning with the fin open. The effect of this expansion appeared 

 to Hugh Smith " exceedingly striking and pretty, the fin looking 

 like silver, and when several of the fish were in company the flash 

 caused by a fin being opened, now here, now there, now on one side 

 of a fish, and then on the other, heightened the effect considerably. 

 It was curious to note, when the expanding fin was closed, how com- 

 pletely it disappeared, altering the appearance of the fish entirely." 

 Sometimes in sport, sometimes to escape pursuing enemies, with 

 increased vigorous movements of the tail, they spring out of the 

 water, immediately spread their pectoral and ventral fins, and start 

 an aerial progress known as flight. 



The so-called flight of the flying fishes has been the subject of much 

 heated controversy. The coolest and most scientific treatment of 

 the question has been made by Karl Mobius, and most of the best 

 equipped recent investigators have come to the same or similar con- 

 chisions as he did. Flying fishes do not fly any more than flying 

 squirrels, flying opossums, flying lemurs, flying lizards, or flying 

 frogs; they do not fly like birds or bats or most insects. The answer 

 to the question, " Do flying fishes fly? " will therefore depend on what 

 is called flight. If flight is the act or result of a volitional series of 

 beats of the wings, as in birds, then fishes do not fly ; if the word be 

 extended to cover the use of quasi-Avings for inactive sustentation of 

 the body or as parachutes, as in flying squii'rels or flying opossums, 

 tlien flying fishes may fly. 



M(")bius (1878, 1885) contended that "Flying fish are incapable 

 of fyhig [the italics are his] for the simple reason that the muscles 

 of their pectoral fins are not large enough to bear the weight of their 

 body aloft in the air. The pectoral muscles of birds depressing their 



