616 THE EAR 



and is directly inserted into the neck of the stapes close to the 

 articulation of the orbicular process of the incus. 



The ligaments of the malleus are the anterior, the external, and 

 the superior. The anterior ligament firmly attaches the head of 

 the malleus to the margin of the Glasserian fissure in the anterior 

 wall of the tympanum. The processus gracilis of the malleus is 

 inclosed by the fibres of this ligament. It is also in close relation 

 with the chorda tympani, which, being clothed by the tympanic 

 mucosa, traverses this portion of the tympanic cavity and enters 

 the iter chordae anterius. 



The external ligament connects the neck of the malleus with 

 the upper portion of the external wall of the tympanum. It is 

 somewhat fan-shaped. The superior ligament is a looser fibrous 

 band which passes from the head of the malleus to the superior 

 wall of the tympanum. 



The ligament of the incus is decidedly fan-shaped, its straight, 

 coarse, fibrous bands radiating from the short process of the ossicle 

 to the adjacent portion of the posterior wall of the tympanum. 



The articulation of the malleus with the incus, as also that of 

 the latter bone with the stapes, is supplied with a delicate capsu- 

 lar ligament. 



The annular ligament of the stapes connects the margin of the 

 foot plate of this bone with the adjacent portions of the cartilagi- 

 nous and bony wall of the vestibule at the margin of the fenestra 

 ovalis. The articulation which is thus inclosed is directly formed 

 by an annular plate of cartilage investing the margin of the oval 

 foot of the stapes, and a similar annular plate of hyaline cartilage 

 which lines the borders of the foramen ovalis. The fibres of the 

 annular ligament are continuous with those of the perichondrium 

 and adjacent periosteum. 



THE EUSTACHIAK TUBE 



The Eustachian tube connects the cavity of the tympanum with 

 that of the naso-pharynx. Its first portion is surrounded by a 

 bony wall ; beyond this it is supplied with a cartilaginous plate ; 

 its pharyngeal ostium is entirely membranous. 



The mucosa consists of an epithelium, which is of the columnar 

 ciliated variety, continuous with, and similar to the respiratory 

 epithelium of the naso-pharynx, together with a fibrous membrana 

 propria which is loosely connected with the surrounding bony, car- 

 tilaginous, and muscular walls. The lower portions of the tube are 



