THE SENSES 



957 



parent fibres arranged radially i.e., in the direction from limbus to 

 spiral ligament. They are embedded in a homogeneous material. 

 Below the cochlear canal ends blindly, but communicates by a 

 side-channel with the portion of the membranous vestibule called 

 the saccule, which in its turn communicates with the utricle by 

 the Y-shaped origin of the ductus endolymphaticus. Into the utricle 

 open the three semicircular_canals, the endolymph of which has, 



str.v, 



w 



FIG. 422. LONGITUDINAL SECTION THROUGH THE COCHLEA OF A CAT (SCHAFER, 

 AFTER SOBOTTA). x 25. 



dc, canal or duct of cochlea ; scv, scala vestibuli ; set, scala tympani ; w, bony 

 wall of cochlea ; C, organ of Corti ; mR, Reissner's membrane ; n, fibres of cochlear 

 nerve ; gsp, ganglion spirale ; str.v., stria vascularis. 



therefore, free communication with that of the vestibule and cochlea. 

 But although the semicircular canals and vestibule belong anatomi- 

 cally to the internal ear, and are supplied by branches of the auditory 

 nerve, we have no positive proof that in the higher animals, at least, 

 they are in any way concerned in hearing ; and since experiment 

 has assigned them a definite function of another kind (p. 834), we 

 shall not consider them further in this connection. The scala media 



