LARYNX OF MAMMALIA. 



583 



454 



ib. d, the thyroid, ib. h, i, the ( arytenoid,' ib. a, a, and the epi- 

 glottis, ib. f. 



The more immediate impressors of e sonorous vibrations ' upon 

 the air trans versing the larynx are the elastic fibres stretched 

 between the arytenoid and 

 the thyroid cartilages, thence 

 termed ' chorda? vocales,' and 

 ' thyro-arytenoid ligaments ; ' 

 of which one is distinguished 



o 



as the ' upper,' fig. 454, /, the 

 other as the ( lower vocal cord,' 

 ib. k. They intercept a space 

 71, where the lining membrane 

 bulges outward, and in Man 

 backward, forming the ( laryn- 

 geal sac ' or ( ventricle.' In 

 this section are shown the hyo- 

 epiglottic ligament b, the thy ro- 

 hyoid ligaments c, the glosso- 

 epiglottic ligament e, the crico- 

 thyroid ligament f, and its 

 junction with the lateral crico- 

 thyroid ligament at g, i, and 

 with the base of the arytenoid 

 cartilage at n f . 



AVith this brief indication of 

 the chief parts of the larynx in 

 Man, its comparative anatomy 

 may be better followed. 



In the Monotremes the superior larynx presents some remark- 

 able modifications in the Ornithorhynchus. The thyroid cartilage, 



> / O 



fig. 455, c, in this animal is very broad ; its middle 

 part is prominent and acuminate : the lateral alre are 

 bony, and each of them divides, and sends one of the 



v * 



processes to the posterior part of the pharynx, ib., 

 where it becomes cartilaginous, and is confluent with 

 the corresponding process of the opposite side. The 

 cricoid cartilage, ib. d, is ossified at its middle ante- 

 rior part. The arytenoid cartilages, ib. e, e, present 

 the usual triangular form, and are of large size. 

 The epiglottis, ib. a, is broad, with an acuminate 

 and notched apex. 



On slitting up the larynx posteriorly, and divaricating the 



A longitudinal section of the larynx : Man. ccxvn". 



455 



Larynx of Orni- 

 thorhyuchus. 



