THE SENSE OF HEARING IN FISHES. 87 



sounds generated in the air yielded negative results. Kreidl's 

 (1895, p. 458) inability to stimulate goldfishes by bells and whistles 

 may thus be explained as well as Lee's (1898, p. 137) failure to get 

 responses to the human voice, clapping of hands, and striking to- 

 gether of stones. This may also have been the case with the ex- 

 periments of Marage (1906), notwithstanding the care with which 

 a translating diaphragm was used, and it seems quite certainly to 

 have been true of Bernoulli's observations (1910, p. 643), accord- 

 ing to which Lucioperca failed to respond to a pistol shot from a 

 boat at the distance of two kilometers. When fishes in water do 

 respond to sounds made in the air, as in the case of Amiiirus (Maier, 

 1909; Haempel, 191 1; Parker and Van Heusen, 1917), it must be 

 taken as evidence of very unusual sensitiveness. As a rule such re- 

 sponses are not to be expected, for, as already stated, sound in the 

 air enters water to only a very slight degree. 



The production of sounds by fishes is not without its bearing on 

 the question of fish hearing. Kreidl (1895, p. 463) appreciated 

 this side of the problem when he argued that "Die Thatsache, dass 

 es auch Fische gibt, die Tone hervorzubringen im Stande sind, 

 welche moglicher Weise den Zweck haben konnen, as Lockmittel zu 

 dienen, lasst immerhin die Moglichkeit zu, dass bei diesen Species 

 bereits eine geringe Ausbildung des Gehororganes stattgefunden 

 hat." The importance of testing such species was emphasized by 

 Lang (1903, p. 48). In the seventh volume of the "Cambridge 

 Natural History," Bridge (1904, pp. 355-365), after remarking 

 that " contrary to popular belief sound-producing or vocal organs 

 are by no means uncommon in fishes," gives an extended account of 

 the various means that fishes possess for the production of sounds. 

 In some instances the sounds produced by them are unquestionably 

 accidental accompaniments of other types of activity, but in other 

 cases the sounds are dependent upon such differentiated mechanisms 

 that it is impossible to attribute these emanations to accident. One 

 instance alone will suffice. Of the fishes studied by Parker (i903a_, 

 p. 48: 1910&) Cynoscion produces a deep drumming sound audible 

 when the fish is in the air to a distance of at least fifty feet. This 

 sound is produced only by the males (Smith, 1905, p. 377) and 

 Tower (1908) has shown that it results from the vibratory action 



