492 VOICE AND SPEECH. 



It is impossible to give a complete account of the structure 

 of the larynx, without going more fully than is desirable into 

 purely anatomical details. Some anatomical points have 

 already been referred to under the head of respiration, in 

 connection with the respiratory movements of the glottis ; 1 

 and we propose here only to refer to the situation of the 

 vocal chords, and to indicate the modifications that they 

 can be made to undergo in their relations and tension by 

 the action of certain muscles. 



The vocal chords are stretched across the superior open- 

 ing of the larynx from before backward. They consist of 

 two pairs. The superior, called the false vocal chords, are 

 not concerned in the production of the voice. They are less 

 prominent than the inferior chords, though they have nearly 

 the same direction. They are covered by an excessively thin 

 mucous membrane, which is closely adherent to the sub- 

 jacent tissue. The chords themselves are composed of 

 fibres of the white inelastic variety, mixed with a few elas- 

 tic fibres. 



The true vocal chords are situated just below the superior 

 chords. Their anterior attachments are near together, at the 

 middle of the thyroid cartilage, and are immovable. Pos- 

 teriorly they are attached to the movable arytenoid carti- 

 lages ; and by the action of certain muscles, their tension 

 may be modified, and the chink of the glottis may be opened 

 or closed. These ligaments are much larger than the false 

 vocal chords, and contain a very great number of elastic 

 fibres. Like the superior ligaments, they are covered with 

 an excessively thin and closely adherent mucous membrane. 

 According to M. Fournie, the author of a very elaborate and 

 recent work on the voice, the mucous membrane over the 

 borders of the chords is covered with pavement-epithelium, 

 without cilia. 2 There are no mucous glands in the mem- 

 brane covering either the superior or the inferior chords. 



1 See vol. i., Respiration, p. 358. 



2 FOURNIE, Physiologie de la voix et de la parole, Paris, 1866, p. 129. 



