LARYNX OF MAMMALIA. 



m 



454 



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

 glottis, ib. f. 



The more immediate impressors of ' sonorous vibrations ' upon 

 the air transversing the larynx are the elastic fibres stretched 

 between the arytenoid and 

 the thyroid cartilages, thence 

 termed ' chordae vocales,' and 

 s thyro-arytenoid ligaments ; ' 

 of which one is distinguished 

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

 other as the f lower vocal cord,' 

 ib. k. They intercept a space 

 w, 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 #, the thyro- 

 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 . 



With 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 

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

 part is prominent and acuminate : the lateral alae are 455 



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

 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' 



Larynx of Orni- 

 thorhynchus. 



LXXXl'. 



