10 



THE AMERICAN NATURALIST [Vol. XL 



Flying-fish put on different aspects according to the state of 

 air and sea. One is rather startled at times by the changes in 

 their methods. In oily equatorial calms, I have watched them 

 in numbers flying long distances with their tails in the water and 

 their heads and wings in the air, the body making an angle of 

 perhaps 30° or 40° with the horizon. The wake left in the water 

 by the dragging tail showed, as well as I could judge, no signs of 

 its having been used for purposes of propulsion, even in its own 

 element, and it is, perhaps, simply to relieve the fish of its weight 

 that it is so supported when there is no fear of the wings being 

 caught by ruffled water; nevertheless the peculiar long lower half 

 of these tails specially adapts them for use as auxiliary propellers 

 to a fish which, with their exception is "a fish out of water"; and 

 it looks so like a case of natural evolution, that I feel inclined to 

 doubt the justice of my personal observation as to their non-use. 



It would seem, from this habit, reasonable to suppose that the 

 fish have the power of flapping their wings at various angles, as 

 have birds, as ordinarily their bodies are fairlv horizontal as thev 



fly- 



The flight of these fish is often described as "graceful," "light," 

 and so on. To him who believes that they soar along easily for 

 200 yards without further effort than a pnliininarv leap from 

 the sea, such an opinion may be a natural one. 



To him who recognizes that such a leap is mechanically impos- 

 sible, whether or not assisted by a continuous tail-movement, or 

 to him, who, without thinking particularly about it, simply sees 

 the heavy laboring of the wings as the fish patiently whirrs along 

 its even, uneventful way, "graceful" and "light" are terms mis- 

 placed. Strenuous, persistent, plodding effort is the impression 

 left upon the mind, the least failure in which effort means plump- 

 ing into the water. One often sees this happen obviously without 

 intention on the fish's part. 



In conclusion, it is, I think, made clear:— 



1. That flying-fish would recjuire to have a wing-area several, 

 anil probably many rimes greater, according to their weights, 

 than they actually possess to enable them to accomplish sailing 

 flight in even such a restricted form as that carried out by sailing 

 birds. 



