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



the superior aperture of the larynx." These are manifestly three 

 very different things, and it is that of the superior aperture which 

 was effected by the epiglottis according to the old doctrine. On 

 account of this looseness of diction, the experiments of John Reid 

 lose most of their value in this connexion. 



Now when one reflects that closure of the glottis merely would 

 still leave patent all that portion of the laryngeal cavity above the 

 level of the glottis, the vestibule, a region exquisitely sensitive to 

 mechanical irritation, one immediately perceives that if the epiglottis 

 does not effect the closure, then some other agency must exist where- 

 by the superior aperture of the larynx, its very entrance, is closed 

 against the entrance of food particles during deglutition. It is quite 

 immaterial where the closure takes place so far as closure of the 

 larynx during forced efforts is concerned, but it is not immaterial 

 where it is effected in deglutition, for the superior aperture, at least, 

 must be closed, however much farther downwards the closure takes 

 place. Were it to remain open, the vestibule of the larynx would be 

 a regular funnel specially adapted, as it were, to take up particles of 

 food. Such particles after the act of deglutition is over would need 

 to be expelled by a violent expiration, a cough, or they would by their 

 weight fall into, or by the force of the inspiratory air blast they would 

 be drawn into, the lower passages. Now these things do not happen, 

 so that a priori even, we may assume that the actual entrance to 

 the larynx is closed, and experimentally I have seen that it is closed, 

 while, on the other hand, Longet kept the margins of the glottis so 

 apart that that aperture could not be closed, and .yet the act of 

 swallowing was carried out normally. 



It may be well to give a straightforward account of how I have 

 observed the larynx to be closed, and I shall then give details of 

 experimental observations. 



The observations were made on 



1. A man who had a large part of the side wall of the pharynx 

 removed for carcinoma, without in any way interfering with the 

 larynx. The man made a good recovery, and when feeding by the 

 use of the stomach-tube was discontinued, he immediately swallowed 

 as perfectly as he ever afterwards did, so that no education of the 

 parts seemed necessary, and he continues to swallow about as well 

 as he ever did, so that in function the parts are practically unim- 

 paired. This man usually wears a rubber pad over the hole, but 

 upon the removal of the same, that is, even with the hole open, one 

 can watch with the unaided eye many of the phenomena of voluntary 

 closure of the larynx, swallowing, coughing, singing, and so on. 

 With the hole open a bolus of solid food is successfully swallowed, 

 perhaps once out of three attempts ; the other two times it will escape 

 by the open hole. 



