NATURE'S OWN SEAPLANES HUBBS 347 



skid. However, if we consider the relation of the part anterior to the vertical 

 to that posterior to it we find that the percent anterior rapidly rises from being 

 equal to considerably exceeding the posterior portion in area. In the much 

 larger planes a similar measurement is still greater, an average of the four 

 planes measured being SO percent. The excess of the " posterior ventral " over 

 the " posterior dorsal " appears to increase with size, which is to say that the 

 lower caudal lobe (the power plant) becomes relatively larger with an increase 

 in absolute size. Here again we would expect to find no correlation with an 

 airplane, and there is none. 



Horizontal directional stability is attained by vertical vanes as in a plane 

 and should be much greater in forms with high vertical fins such as Patexo- 

 coetus than those with low. 



After a fish once leaves the water it is able to rise higher, holding its level 

 with a decreasing speed by altering its camber and lateral dihedral, or in taking 

 advantage of air currents. There is, of course, a point of maximum eflBciency 

 which could be worked on mathematically and would doubtless be close to that 

 actually observed. In this respect fish flight is clearly very close to that of 

 sail-planes. Dowd (1921) has examined exocoetids in great detail and finds 

 them to be constructed close to the lines used in the best aeronautical engi- 

 neering. 



" Nature's Own Seaplanes " the flying fishes may surely be called. 

 Flying fishes are indeed an outstanding example of the fidelity with 

 which nature long ages ago anticipated, in the evolution of animals, 

 both ancient and modern inventions of man. 



SELECTED REFERENCES 

 AUUJOBJT, Fb. 



1895. Der Flug der Fische. Real Gymnasium des Johanneums, zum 70. 

 Geburtstage Prof. Dr. Karl Mobius, pp. 1-56, 3 figs., 1 pi. Hamburg. 

 Bbedeb, C. M. Jr. 



1929. Field observations on flying fishes; a suggestion of methods. 

 Zoologica, vol. 9, pp. 295-312, figs. 301-305. 



1930. On the structural specialization of fiyiug fishes from the standpoint 

 of aerodynamics. Copeia, 1930, no. 4, 114-121, figs. 1-3. 



Derjugin, K. 



1908. Die Eutwicklung der Brustflossen und des Schultergfirtels bel 

 Exocoetus volitans. Zeitschr. Wiss. Zool., vol. 91, pp. 559-598, pis. 23-26. 

 Gill, Theodobe. 



1905. Flying fishes and their habits. Ann. Rep. Smithsonian Inst., 1904, 

 pp. 495-515. 

 Uankin, E. II. 



1914. Animal flight : a record of observation. Iliffe and Sons, London. 

 1920. Observations on the fiight of flying fishes. Proc. Zool. Soc. London, 

 no. 2, pp. 467-^74, figs. 1-2. 

 HuBBS, Gael L. 



1918. The flight of the California flying flsh. Copeia, 1918, no. 62, pp. 



85-88. 

 1932. Observations on the flight of flshes, with a statistical study of the 

 flight of the Cj'pselurinae and remarks on the evolution of the flight of 

 flshes. Pap. Michigan Acad. Sci., Arts and Letters, vol. 17, pp. 575-611, 

 figs. 66-68. 



