SUPERIOR AND INFERIOR VOCAL CORDS. 625 



the inferior vocal cords, so as to obliterate the ventricles of 

 Morgagni, at the same time they ulso meet in the median line ; 

 (3) the epiglottis being lowered, and its cusliion becoming more 

 prominent still, it presses against the closed glottis ; the contact 

 takes place from before backwards. These three-fold occur- 

 rences in the hermetic closure of the larynx explain the resist- 

 ance which the glottis successf villy opposes to the pressure of 

 the air, without a development of much force during the effort." 

 Czermak also gives an accurate picture of the appearance of 

 the glottis when coiupletely closed during effort, though a still 

 better one is given by Grlitzner in Hermann's Ilandh, Ji der Pkys. 

 (Band 1, Theil 2, page 59). In Griitzner's picture (Fig. 214) 



Tig. 214. — Glottis closed by the approximation of the false vocal cords (/. s.) 



after Griitzner. 



the rounded and bulging nature of the protuberances formed by 

 the false vocal cords is very evident, and suggestive of inflation 

 from below. Grtitzner, however, only remarks that the false 

 vocal cords, or ventricular bands, are often approximated, and 

 the cushion of the epiglottis depressed upon them, whereby a 

 very firm closure is produced. In an inaugural thesis presented 

 to the Edinburgh University by Dr. Wyllie in 1865, the author 

 discussed the mode of closure of the glottis very fully, and 

 illustrated it by very numerous experiments. These showed 

 very clearly, indeed, what an important part is played in the 

 closure of the glottis during expiration by the false vocal cords, 

 and that, indeed, it is chiefly if not entire y through them that 

 the closure is usually accomplished. These experiments were 

 published in the Edinhurgh Medical Journal, September, 1866, 

 but as they are not referred to in many standard text-books,* it 



* We must except Turner'* introduction <o Human Anatomy, in which these 

 •experiments are referred to. 



2 s 



