238 BT HOOK AND BY CBOOK. 



long journeys has been proved^ which, under certain 

 circumstances, may be obligatory or even accidental. 



When it is considered how much lee way in point of 

 condition the kelt has to make up on return to salt 

 water, and his rapid growth while therein, a course of 

 comparative inactivity does not appear unreasonable. 



As regards the sense of hearing of fish, in the absence 

 of discovery of aural structures, it is pretty generally 

 accepted that they possess no mechanism similar in con- 

 struction to the ear ; yet it is possible, even probable, 

 that they possess some organ susceptible to the effect 

 produced by concussion, and capable of conveying it 

 to the brain. 



This structure, it is reasonable to assume, is delicate 

 in form, and, as has been suggested, may well be the 

 flat, independent bone situated on the top of the snout. 



It may be doubted if this fan-shaped structure is 

 sufficiently delicate to record the transmittal by water 

 of wave-sounds such as those produced by the human 

 voice, and as upon occasions, when close to fish but 

 concealed from their view, we have shouted with no 

 efi*ect, we question this possibility. 



Concussion produced by bringing an object in con- 

 tact with water is another matter, and would be more 

 easily conveyed to the fish ; and as when, from a con- 

 cealed position, we have cast a heavy object into water 

 behind a fish he has responded, we cannot but think 

 that he was informed of the occurrence. 



