3 52 THE FACULTY OF HEARING. 



the view of determining the true locality of the insect auditory 

 organ, and the nature and limits of its hearing power ; though the 

 result scarcely justifies the slaughtered hecatombs of the doctor, 

 who certainly seems to have as little scruple of conscience as fear 

 of parliamentary penalty. 



The anatomy of this tympanal structure, the most unique and 

 striking organ yet discovered in any insect, presents many points 

 of interest for the specialist. But its great significance lies in the 

 evidence it may afford towards the settlement of the question, 

 whether a true hearing apparatus exists in the insect, and what 

 kind of auditory sense it enjoys. For although there can be no 

 doubt that a sense of vibration conveyed through air, fluid, or solid 

 media, is felt by all insects, and a sense of sound by many, no 

 organ of hearing has yet been discovered which exactly corresponds 

 with known types of construction. It is far from certain that 

 insect hearing is of the same nature that we conceive it to be in the 

 higher vertebrata ; and therefore a two-fold interest attaches to the 

 determination of the exact function of this tympanal structure, not 

 only because it is (presumably) a sensory organ, possessing a 

 complex development and a quite remarkable differentiation of 

 Its terminal nerve elements, (resembling the highest examples of 

 nerve distribution in sensory organs), but also because there exists 

 no organ like it, as a whole, in any creature possessing an ear of 

 ordinary type. If the tym.panal structure be not an auditory 

 apparatus, the Inference Is scarcely to be avoided that It Is instru- 

 mental to a new sense, or a new form of sensory organ for 

 reception of vibrating impulses, the consciousness of which may be 

 akin to that of tactile impression, or perhaps something between 

 touch and hearing. 



To understand the bearings of this question, and rightly grasp 

 the points upon which particular issue might be raised, it is 

 necessary to keep in mind the several physical and physiological 

 conditions under which an auditory faculty may be exercised. So 

 also before we can determine how far any given structure answers 



