THE INTERNAL EAR OR LABYRINTH 



1053 



filaments of the acoustic nerve enter these parts, and having pierced the outer and middle layers, 

 they lose their medullary sheaths, and their axis-cylinders ramify between the hair cells. 



12 



1' 20 5" 19181716 15 



14 13 



FIG. 925. Right human membranous labyrinth, removed from its bony enclosure and viewed from the antero-lateral 



aspect. (G. Retzius.) 



IS 



23 11 8, 9, 10 Iff 5 6 3' 6 20' 4 

 f f 



FIG. 926. The same from the postero-medial aspect. 1. Lateral semicircular canal; 1', its ampulla; 2. Poste- 

 rior canal; 2', its ampulla. 3. Superior canal; 3', its ampulla. 4. Conjoined limb of superior and posterior 

 canals (sinus utriculi superior). 5. Utricle. 5'. Recessus utriculi. 5". Sinus utriculi posterior. 6. Ductus endo- 

 lymp_haticus. 7. Canalis utriculosaccularis. 8. Nerve to ampulla of superior canal. 9. Nerve to ampulla of lateral 

 canal. 10. Nerve to recessus utriculi (in Fig. 925, the three branches appear conjoined). 10'. Ending of nerve in 

 recessus utriculi. 11. Facial nerve. 12. Lagena cochleae. 13. Nerve of cochlea within spiral lamina. 14. Basilar 

 membrane. 15. Nerve fibers to macula of saccule. 1(3. Nerve to ampulla of posterior canal. 17. Saccule. 18. 

 Secondary membrane of tympanum. 19. Canalis reunions. 20. Vestibular end of ductus cochlearis. 23. Section 

 of the facial and acoustic nerves within internal acoustic uaeatus (the separation between them is not apparent in the 

 section). (G. Retzius J 



