FUNCTIONS OF THE INTERNAL EAE. 225 



complete deafness. 1 In additioti, it was observed that de- 

 struction of the semicircular canals on both sides was fol- 

 lowed by remarkable disturbances in equilibration. The 

 animals could maintain the standing position, but, as soon as 

 they made any movements, " the head commenced to be agi- 

 tated ; and this agitation increasing with the movements of 

 the body, walking and all regular movements finally became 

 impossible, in nearly the same way as when equilibrium and 

 stability of movements are lost after turning several times or 

 violently shaking the head." 2 These observations of Flou- 

 rens, at least as far as regards the influence of the semicir- 

 cular canals upon equilibration, have been confirmed by 

 Goltz, and are sustained by observations on the human sub- 

 ject in the condition known as Meniere's disease. 8 In some 

 more recent experiments, however, Boettcher assumes to have 

 demonstrated that the semicircular canals have nothing to do 

 with equilibration; but all of his observations were made 

 upon frogs, in which deficiency of equilibration and of hear- 

 ing would be very difficult to determine. 4 As far as we can 

 judge from experimental data, it does not seem probable 

 that the nerves directly concerned in audition are distributed 

 to any considerable extent in the semicircular canals. In- 

 deed, the function of these parts is exceedingly obscure ; for 

 we can hardly admit, upon purely anatomical grounds, that 

 they are concerned in the discrimination of the direction of 

 sonorous vibrations, an idea which has been advanced by 

 some physiologists. 



Functions of the Parts contained in the Cochlea. There 

 can be no doubt with regard to the capital point in the phys- 

 iology of the cochlea ; namely, that those branches of the 



1 FLOURENS, JRecherchcs experimentales sur les proprietes et lesf auctions dusys- 

 t&me nerveux, Paris, 1842, p. 443, et seq. 



2 Op. cit., p. 446. 



3 See vol. iv., Nervous System, pp. 369, 387. 



4 BOETTCHER, Kritische Bemerkungen und neue Bdtrdge zur Literatur des Ge- 

 hvrlabyrintlis.Dorpater medicinische Zeitschrift, Dorpat, 1872, Bd. Hi., S. 108. 



