LIGAMENTS OP THE TYMPANUM. 



453 



face, with the membrana vestibuli, and is covered in by the mucous 

 lining of the tympanum. The neck of the stapes gives attachment 

 to the stapedius muscle. 



Fig. 139 * 



The ossicula auditus are retained in their position and moved 

 upon themselves by means of ligaments and muscles. 



The Ligaments are three in number; the ligament of the head of 

 the malleus, which is attached superiorly to the upper wall of the 

 tympanum : the ligament of the incus, a snort and thick band, which 

 serves to attach the extremity of the short process of that bone to 

 the margin of the opening of the mastoid cells ; and the circular 

 ligament which connects the margin of the foot of the stapes with 

 the circumference of the fenestra ovalis. These ligaments have 

 been described as muscles, by Mr. Tod, under the names of supe- 

 rior capitis mallei, obliquus incudis externus posterior, and mus- 

 culus, vel structura stapedius inferior. 



* A diagram of the ear. p. The pinna, t. The tympanum. I. The labyrinth. 

 1. The upper part of the helix. 2. The antihelix. 3.. The tragus. 4. The antitragus. 

 5. The lobulus. 6. The concha. 7. The upper part of the fossa innominata. 8. 

 The meatus. 9. The membrana tympani, divided by the section. 10. The three 

 little bones, crossing the area of the tympanum, malleus, incus, and stapes ; the foot of 

 the stapes blocks up the fenestra ovalis upon the inner wall of the tympanum. 11. 

 The promontory. 12. The fenestra rotunda ; the dark opening above the ossicula 

 leads into the mastoid cells. 13. The Eustachian tube ; the little canal upon this tube 

 contains the tensor tympani muscle in its passage to the tympanum. 14. The vesti- 

 bule. 15. The three semicircular canals, horizontal, perpendicular, and oblique. 16. 

 The ampulla* upon the perpendicular and horizontal canals. 17. The cochlea. 18. 

 A depression between the convexities of the two tubuli which communicate with the 

 tympanum and vestibule ; the one is the scala tympani, terminating at 12 ; the other is 

 the scala vestibuli. 



