132 ORGANS OF RESPIRATION. 



lour, resembling the letter L, and consists in distinct grains; it 

 is supposed to have its excretory ducts opening into the larynx. 

 It is frequently wanting. 



The Interior Face of the Larynx is lined by a mucous mem- 

 brane, continuous above with that of the mouth and pharynx, 

 and below with that of the trachea. Where it is reflected from 

 the base of the tongue to ^Jie epiglottis cartilage, it forms, as 

 described, a well-marked vertical fold or fraenum in front of 

 the middle of the latter, and on each side of this middle fold 

 there is another, not so distinct, but varying in different sub- 

 jects. Beneath the middle fold is the strong fibro -muscular 

 connexion with the root of the tongue.* The three folds form 

 two pouches in front of the epiglottis, in which food is some- 

 times lodged. The mucous membrane also forms the duplica- 

 ture on each side already alluded to, which passes from the la- 

 teral part of the epiglottis cartilage to the arytenoid of the 

 same side of the body. This duplicature forms the superior 

 boundary of the cavity of the larynx, and is very soft and ex- 

 tensible, permitting freely the epiglottis to be depressed and to 

 rise again into its vertical position. The duplications of the 

 two sides, taken together, form an oblong oval opening into the 

 larynx, passing very obliquely upwards and. forwards to the 

 epiglottis, and terminated behind by a notch between the cor- 

 nicula laryngis. At the latter place the mucous membrane is 

 wrinkled and loose, so as to permit, by its extensibility, free 

 motion to the arytenoid cartilages. 



After adopting the preceding arrangement, the lining mem- 

 brane of the larynx passes downwards; it covers smoothly the 

 posterior face of the epiglottis, adhering closely to it; but, \vhei> 



* A muscle of a triangular shape has lately been observed by the English 

 anatomists,! situated in front of the epiglottis, passing to it from the base of the 

 os hyoides: it is called Hyo-Epiglottideus. The observations on its existence 

 have not yet been repeated sufficiently often to determine whether it belongs to 

 the normal structure of the body or not; and in my own dissections, for the pur- 

 pose of assertaining its existence, it has not occurred. Albinus, Soemmering, 

 and others, speak of the occasional existence of muscular fibres there. A strong 

 muscle is found there in the lower animals, as stated in the description of the 

 tongue, vol. 1st. 



t Am. Med. Jour. vol. v. p. 475. 



