336 Prof. T. P. Anderson Stuart. [Jan. 21, 



quoted by Luschka) in the case of a girl who had lost the epiglottis 

 by nlceration, but Luschka concludes from a consideration of other 

 cases that this was a mere accommodation gradually effected by the 

 muscles " by prolonged practice acquiring the necessary strength to 

 mutually approximate the side walls" of the vestibule. In the 

 case reported by myself with McCormick already referred to, 

 the patient, immediately upon the cessation of feeding by the 

 stomach-tube, could swallow as well as he did later on, and to all 

 intents and purposes as well as he could before the operation, and in 

 him we were able to see by merely looking through the hole in the 

 side of the neck, that the laryngeal closure was accompanied by the 

 ~|~-shaped fissure. Here, therefore, there was no "prolonged 

 practice " ; there was no practice at all, and the same remark applies 

 to the cases already quoted as having been examined for me by Barrett. 

 The fissure is also shown in Czermak's classical work, but the forma- 

 tion of the head of the "f" is misinterpreted ; it is said to be by the 

 backward movement of the epiglottis, instead of by the forward 

 movement of the arytenoids. 



Short of complete closure, the arytenoid flap comes forward so that 

 it is approximated to the front wall of the laryngeal cavity, therefore, 

 in Man, to the epiglottis, and if air be now expired, the characteristic 

 sound of straining is produced by the vibration of the margins of the 

 entrance to the air passages, not of the vocal cords merely. 



Lister (Holmes ' Surgery,' Article on " Anaesthetics ") ascertained 

 laryngoscopically that true chloroform stertor is produced by vibration 

 " of the posterior part of the arytaeno-epiglottidean folds, which 

 are carried forwards to touch the base of the epiglottis during the 

 stertorous breathing, and are placed in still further apposition with 

 it when the obstruction becomes complete." Thus, Lister saw "an 

 antero-posterior co-aptation of the structures of the laryngeal aperture 

 at a somewhat deeper level ; without any change in the position or 

 form of the epiglottis, towards which the folds of the mucous mem- 

 brane above the apices of the arytenoid cartilages are carried forwards 

 till they are in contact with its base. This is seen in coughing and 

 also in laryngeal stertor." Nevertheless, the closure by the epi- 

 glottis is the mode of closure Lister adopted for deglutition. 



In certain lesions of the true cords, the gruff voice is, as Sir Joseph 

 Lister communicated to me orally, to be ascribed to a vibration of 

 the ary-epiglottic folds, a suggestion with which I entirely agree. 

 I believe also that in gargling, the larynx is almost closed, and the 

 air issues under pressure from the narrow fissure I have described. 



In the Kangaroo apparently a great extent of the arytenoids is ex- 

 posed to the friction of the passing bolus, and along the ridge of the 

 apposed arytenoids, where the friction takes place, the cartilage shows 

 through, and the mucosa is not movable. In the human larynx this 



