Prof. A. M. Mayer's Researches in Acoustics. 373 



with the physical conditions necessary for them to receive and 

 transmit vibrations to the interior ganglia. 



Naturalists, in their surmises as to the positions and forms of 

 the organ of hearing in insects, have rarely kept in view the im- 

 portant consideration of those physical relations which the 

 organ must bear to the aerial vibrations producing sound, and 

 which we have already pointed out. The mere descriptive ana- 

 tomist of former years could be satisfied with his artistic faculty 

 for the perception of form ; but the student of these days can 

 _ only make progress by constantly studying the close relations 

 which necessarily exist between the minute structure of the 

 organs of an animal and the forces which are acting in the 

 animal, and which traverse the medium in which the animal 

 lives. The want of appreciation of these relations, together 

 with the fact that many naturalists are more desirous to de- 

 scribe many new forms than to ascertain the function of one 

 well-known form which may exist in all animals of a class, 

 has tended to keep many departments of natural history in the 

 condition of mere descriptive science. Those who are not pro- 

 fessed naturalists appreciate this perhaps more than the na- 

 turalists themselves, who are imbued with that enthusiasm 

 which always comes with the earnest study of any one depart- 

 ment of nature ; for the perusal of those long and laboriously 

 precise descriptions of forms of organs without the slightest 

 attempt, or even suggestion, as to their uses, affects a physi- 

 cist with feelings analogous to those experienced by one who 

 peruses a well-classified catalogue descriptive of physical in- 

 struments, while of the uses of these instruments he is utterly 

 ignorant. 



The following views, taken from the 'Anatomy of the Inver- 

 tebrata' by C. Th. v. Siebold, will show how various are the 

 opinions of naturalists as to the location and form of the organs 

 of hearing in the Insecta : — " There is the same uncertainty 

 concerning the organs of audition (as concerning the olfactory 

 organs). Experience having long shown that most insects per- 

 ceive sounds, this sense has been located sometimes in this and 

 sometimes in that organ. But in their opinion it often seems 

 to have been forgotten, or unthought of, that there can be no 

 auditory organ without a special auditory nerve which connects 

 directly with an acoustic apparatus capable of receiving, con- 

 ducting, and concentrating the sonorous undulations. (The 

 author who has erred most widely in this respect is Mr. L. W. 

 Clarke in Mag. Nat. Hist., September 1838, who has described 

 at the base of the antenna? of Carabus nemoralis, Illig., an audi- 

 tive apparatus composed of an auricula, a meatus auditorius 

 externus and internus, a tympanum and labyrinthus, of all of 



