Mechanism of the Larynx. 



M3 



Magendie, to open the glottis by separating the arytenoids, but by 

 Sommering and Bichat to close it. Other writers follow one or 

 other of these opinions, combining - the different muscles after their 

 own fashions, without attempting to support their statements by 

 mechanical reasoning deduced from the structure and connexion 

 of the parts. In the following table I have brought together the 

 functions of the muscles according to the views I have taken 

 in the preceding pages. 



1 1 Cricoth yroTdei stretch the vocal ligaments 



ThyroarytenoYdei relax the vocal ligaments, 

 and place them in the 

 vocalising position 



Govern the pitch 

 of the notes. 



CricoarytenoTdei postici open the glottis \ 



Cricoarytenoidei late rales press together the 



front portion of 

 the Arytenoids . . 



ArytenoTdei transversi 



et obliqui press together the hin- 

 der portion of the 

 Arytenoids 



together close 

 the glottis. 



Govern the aperture 

 of the glottis. 



Lest it should appear to some of my readers that I have, in 

 stating the uses and actions of the several parts of the Larynx, 

 expressed myself more decidedly than I ought to have done, I 

 beg to state that this decided style was adopted for the sake of 

 brevity, and that it is with the greatest deference that I have ven- 

 tured to offer opinions in many cases so different from those of 

 former writers. At the same time I have endeavoured to explain 

 the mechanical grounds of these opinions as clearly as possible, 

 and to distinguish carefully between those portions of my ex- 

 planation that rest on mechanical facts, and those that arc merely 

 deduced from inductive reasoning. 



ROBERT WILLIS. 



