THE EAR 



291 



ends in a blind sac in the cupola ; at the base it passes into 

 the inner chamber of the membranous labyrinth. 



L.o: 



M.b. 



FIG. 42. CROSS-SECTION OF THE LAMINA SPIRALIS MEMHRANACEA. 



Z0, lamina spiralis ossea; N, cochlear nerve; n n, nerve fibres; C C, pillars of 

 Corti; J//, membrana tectoria; Mb, membrana basilaris; h, hair cells; Jlfy, mem- 

 brana reticularis; d, Deiter's cells; lid, habenula denticulata; Hp, habenula 

 perforata. 



The membranous labyrinth (see Fig. 43) is a membranous 

 covering of the vestibule and the posterior part of the laby- 



K 



FIG. 43. Tin-: MEMBRANOUS LADVRINTH (DIAGRAMMATIC). 



U, utriculus with the semicircular canals; S, sacculus; C, cochlea; A', cupola; 

 v, cul-de-sac of the vestibule; C>, canalis reuniens; A', ductus endolymphaticus. 



rinth, the semicircular canals (see page 294). In the vesti- 

 bule the membranous labyrinth is divided by constriction 

 into two parts, the anterior sacculus and the posterior 

 utriclus. 



The membranous labyrinth is filled by the endolymph, 



