THE INTERNAL EAR, OR LABYRINTH 



1143 



where, and form the macula acustica utriculi, which receives the utricular filaments 

 of the auditory nerve and has attached to its internal surface a layer of calcareous 

 particles which are called otoliths, The cavity of the utricle communicates behind 



Ampulla 



' - , 

 ^ Ductus 

 Endolymphaticus 



FIG. 850. The membranous labyrinth (enlarged). 



with the membranous semicircular canals by five orifices. From its anterior wall 

 is given off a small canal (ductus utriculosaccularis), which joins with a canal from 

 the saccule, the ductus endolymphaticus. 



The Saccule (sacculus) is the smaller of the two vesicular sacs; it is globular 

 in form, lies in the recessus sphaericus near the opening of the scala vestibuli 



NERVE OF AMPULLA AMPULLA OF SU PERIOR 

 UTRICLE OF SUPERIOR CANAL M EM BR AN OUS CA N AL 



SUPERIOR 



TERMINAL 



BRANCH OF 



VESTIBULAR 



NERVE 



DUCTUS 

 COCHLEARIS 



COCHuEAR 

 NERVE 



ACOUSTiC 

 NERVE 



VEST BULAR 

 NERVE 



VESTI&ULAR 

 GANGLION 



NERVE OF NERVE OF AMPULLA EACCULE 

 SACCULE OF POSTERIOR CANAL 



AMPULLA OF POSTERIOR 

 MEMBRANOUS CANAL 



DUCT OF 

 SUPERIOR 

 SEMICIRCULAR 

 CANAL 



AMPULLA OF 

 EXTERNAL 

 MEMBRANOUS 

 CANAL 



DUCT OF 

 EXTERNAL 

 SEMICIRCULAR 

 CANAL 



CRUS 



COMMUNE 



DUCT OF 



POSTERIOR 



SEMICIRCULAR 



CANAL 



DUCTUS ENDO- 

 LYMPHATICUS 



FIG. 851. The right membranous labyrinth or an adult, isolated, medial and posterior view. (Spalteholz.) 



of the cochlea. Its anterior part exhibits an oval thickening, the macula acustica 

 sacculi, to which are distributed the saccular filaments of the auditory nerve. 

 Its cavity does not directly communicate with that of the utricle. From the pos- 



