HEARING 



6i7 



membranous duplicate of the osseous labyrinth, known as the mem- 

 branous labyrinth. This contains a fluid, known as the endolymph. 



ductus endolymph. 



sup. s.c. 



__^ from primitive utricle 

 scafa media \ 



cochfear canal 



FICJ. 376. DIAGRAM OF MEMBRANOUS LABYRINTH. (Keith.) 



Into the central portion of the osseous labyrinth the vestibule 

 the fenestra ovalis opens. Anteriorly from this there arises a con- 

 voluted tube the osseous cochlea which is wrapped around a central 



P.S.Q. 



Fia. 377. DIAGRAM OF RIGHT INTERNAL EAR, SEEN FROM ABOVE. (From Parsons 

 and Wright, "Practical Anatomy.") 



Coch., Cochlea; Prom., promontory; C.C., carotid canal; E.T., Eustachian tube; 

 I. A.M., internal auditory meatus; Vest., vestibule; F.H.E., fovea hemielliptica 

 lodging utricle; C.V., crista vestibuli; St., stapes fixed in fenestra walls; Arj.F., 

 Fallopian aqueduct (for facial nerve); Aq.V ., aqueductus vestibuli; S.S.C., 

 P.S.U., E.8.C., superior, posterior, and external semicircular canals. 



pillar the modiolus. The tube is divided into two by a septum 

 partly bony the spiral lamina and partly membranous the basilar 



