596 



THE TISSUES. 



A section of both the external and internal ear is shown by Fig. 

 421. 



The membranous labyrinth, and the terminations of the vesti- 

 bular nerve, are shown by Figs. 422, 423. 



Fig. 424. 



A view of the labyrinth of the left side, laid open in its whole extent so as to show its structure. 

 Magnified about 12 diameters. 1. The thickness of the outer covering of the cochlea. 2, 2. The 

 scala vestibuli, or upper layer of the lamina spiralis. 3, 3. The scala tympani or lower layer of the 

 lamina spiralis. 4. The hamulus cochleae. 5. Centre of the infundibulum. 6. Foramen opening 

 into the tympanum. 7. The thickness of the puter layer of the vestibule. 8. The foramen rotund- 

 um. 9. The fenestra ovalis. 10. The orifice of the aqueduct of the vestibule. 11. The inferior 

 semicircular canal. 12. The superior semicircular canal. 13. The external semicircular canal. 14. 

 The ampulla of the inferior canal. 15. The ampulla of the superior canal. 16. The common orifice 

 of the superior and inferior canals. 17. The ampulla of the external canal. 



Fig. 425. 



An anterior view of the external ear, as well as of the meatus auditorius, labyrinth, &c. 1. 

 The opening of the ear at the bottom of the concha. 2. The meatus auditorius externus, or carti- 

 laginous canal. 3. The membrana tympani stretched upon its ring. 4. The malleus. 5. The stapes. 

 The labyrinth. 



