298 ELEMENTARY PHYSIOLOGY. [x XVIII. 



of articulation of the incus with the malleus 

 should be observed. 



c. The stapes, much more transparent than 

 the other bones ; the base fits into an oval 

 depression, the fenestra ovalis. Observe 

 the stapedius muscle passing backwards 

 from the head of the stapes to the aque- 

 ductus Fallopii at the lower, outer part of 

 the cochlea. 



8. Take out now the ossicula auditus, and observe 

 further the shape of each. 



9. To the inner side, rather in front of the attach- 

 ment of the tensor tympani muscle, observe the 

 opening of the Eustachian tube ; pass a probe 

 down it and note the phaiyngeal opening. 



10. With a small pair of bone forceps, break away 

 the wall of the cochlea proceeding from the 

 foramen rotundum towards the apex of the bony 

 cone. Observe the coils of the cochlea with the 

 central piece of bone or modiolus and the pro- 

 jecting lamina spiralis. 



11. With a strong pair of forceps remove the periotic 

 bone from the skull and cut through the cochlea 

 down the modiolus. Observe the nerves running 

 up its centre. 



12. Starting from the fenestra ovalis tho vestibule 

 may be exposed, the openings of the semicircular 

 canals seen and traced out in the bone, but this 



