CHAPTER X. 



ON THE HEARING OF FISH. 



By Prof. E. W. Claypole, B. A. B. ' Sc., F. G. S., &c., Buclitel College, 



Akron, Ohio. 



There has been and is still not a little controversy regarding the hear- 

 ing faculty in fish. Some have gone so far as to declare that they can.not 

 hear at all. Evidence has been freely quoted on both sides and both par- 

 ties have apparently made out a case at least to their own satisfaction. 

 When so decided a difference of opinion exists in regard to a question of 

 fact, there must be reason on both sides, and it is necessary to take all 

 these into consideration in order to arrive at the truth. 



Now there are two methods of working in a problem of this kind. 

 They may be called the structural and the experimental methods. Both 

 should be followed up and if the results coincide each will be confirmatory 

 of the other. The former seeks by dissection to show that the organs re- 

 quired for hearing are present in the fish. The latter seeks to prove from 

 their behaviour that fish do hear because they act as if they heard. The 

 former of these methods will be chiefly followed in this paper. The latter 

 can be employed by any one who has access to a fish pond to test the con- 

 clusion reached below. 



No one will dispute the premise that if an animal has an ear or ears 

 that animal should in some degree at least possess the faculty of hearing. 

 Unused organs soon become rudimentary and finally disappear. If con- 

 sequently, fish have ears, we must infer that in some manner or degree 

 they can hear. 



It is not necessary for this conclusion that the sense of hearing should 

 be as perfect or complete as in ourselves, or that the ear should show the 

 same marvelous complexity as it does in man. This would be highly im- 

 probable. The fish zoologically is lower than man equally fitted to get 

 his living in the circumstances wherein he is placed, but not capable of 

 the variety and complexity of actions for which we are adapted. Zoolog- 

 ically speaking therefore, we shall expect to find many if not all of the or- 

 gans of the fish less complete that is less perfect than our own. With 

 increasing complexity of structure comes increasing diversity of function. 

 The complex organ enables its possessor to do what without it would be 

 impossible. New avenues between the outer world and the conscious centre 

 are opened. Possibility of pleasure and of pain previously unrealized 

 and unconceived comes into existence. The animal is higher in the zoo- 

 logical scale. All this will be denied by few and will be at once admit- 

 ted by all zoologists. In fact simplicity of structure is usually tantamount 



