Labyrinth and Semicircular Canals in the Human Ear. 259 



receive a signal by which their conduct is regulated. All that is 

 contended for is that such creatures are destitute of any thing 

 corresponding to that affection of the mind which we designate 

 as the hearing of sound. 



Some writers, indeed, maintain that the sense of hearing is 

 merely a refinement of the sense of touch. To this view of the 

 subject I cannot subscribe. A table may vibrate under the in- 

 fluence of undulations which, when brought to bear upon the 

 ear by means of a rod resting on the table, will produce the sen- 

 sation of hearing. If, under the same circumstances, the table 

 be touched with the finger, the nerves of the finger will be excited 

 by the same vibrations; nevertheless we do not hear through the 

 tips of our fingers. 



As regards the effect produced by sounding bodies upon the 

 nerves of the membranous labyrinth, whether in animals provided 

 with a cochlea or those destitute of that adjunct — as, for instance, 

 in fishes — I am quite disposed to admit that it may be merely a 

 refined example of the sense of touch*; but the perceptions ex- 

 cited in the human subject through the ear — and the same no 

 doubt must in a degree apply to all animals endowed with a 

 cochlea — appear as distinctly sui generis as are those derived 

 through the eye, the nostril, or the palate. 



6 New Square, Lincoln's Inn, 

 January 15, 1870. 



P.S. — The following account relating to the nervous apparatus 

 of the ampullae strikingly illustrates their adaptation to the per- 

 formance of the delicate functions I have ascribed to them : — 



"Dans les ampoules, Max Schultze a decouvert, s'elevant hors 

 de la surface interne de cet epithelium [that of the lining mem- 

 brane of the ampulla? through which the nerves penetrate], des 

 crins elastiques roides tout-a-fait particuliers lis sont beau- 

 coup plus longs que les crins ciliaires des cellules de mica, .... 

 fragiles, et se terminent en pointe tres-fine. De petits crins de ce 

 genre, fins et roides, sont evidemment et h un haut degre propres 

 a suivre les mouvements du liquide, et, par suite, a produire une 

 excitation mecanique dans les cordons nerveux implantes dans 

 leurs bases, dans P epithelium mou 



" Les tumeurs epaisses, situees dans les vestibules ou. viennent 

 se terminer les nerfs, presentent, d^apres Max Schultze, le meme 

 epithelium dans lequel sont inserees les fibres nerveuses, mais 

 point de crins, ou seulement de tres-courts ■" -j\ 



* The fact of the antennae of certain classes of Articulata, through which 

 they are endowed with an exquisite sense of touch, being connected with 

 what have hitherto been regarded as the organs of hearing, is strongly 

 confirmatory of this view. 



t Theorie Physiologique de Musique, &c, par H. Helmholtz. Traduit 

 par M. G. Queroult. Paris, 1868 : p. 172. 



S3 



