CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 269 
the crico-arytenoid membrane ; it fills up the space between the 
cricoid and arytenoids (in which space the latter cartilages move 
laterally, or become approximated), and on either side continuous 
with the elastic tissue of the true vocal chords. 
The thyro-arytenoid ligaments , or chordce vocales, are two in 
number on either side — the anterior, the false ligaments of the 
glottis or false vocal chords, and the posterior, the true ligaments 
of the glottis, or true vocal chords. Between these, on either side, 
are contained a large space, the ventricles of the larynx. The 
anterior or superior arytenoid ligaments are smaller than the pos- 
terior, and are formed internally by the appendages of the epiglottis 
and their ligamentous connexion to the arytenoid cartilages ; ex- 
ternally to these latter, and between them and the thyroid carti- 
lage, are situated the anterior thyro-arytenoid muscles ; and in- 
ternally they are covered by the mucous membrane, which forms 
folds that are attached anteriorly and inferiorly to the angle of the 
thyroid cartilage at the insertion of the epiglottis, and posteriorly 
to the sides of the arytenoids. The posterior arytenoid ligaments , 
or true vocal chords, are larger than the former, and project more 
into the cavity of the larynx, leaving only a small space between 
their free edges — the rima glottidis. In structure they consist of 
a thick, bundle of yellow elastic and white fibrous tissue, attached 
inferiorly to the posterior edge of the thyroid cartilage, and to the 
crico-thyroid membrane ; and superiorly to the bases of the ary- 
tenoid cartilages, their capsular ligaments, and the crico-thyroid 
membrane. Externally to them are situated the posterior thyro- 
arytenoid muscles, and internally they are covered by the mucous 
membrane, which, behind their opposed edges, passes backwards 
over the cricoid cartilage into the trachea. 
The aryteno-epiglottic ligaments are not true ligaments of the 
larynx ; they only consist of duplicates of the mucous membrane 
attached inferiorly to the margins of the epiglottis, and superiorly 
to the appendages of the arytenoids. Between their opposed edges 
is the anterior aperture, or pharyngeal chink of the larynx, and 
between their folds are contained the fibres of the aryteno-epi- 
glot.tidei muscles. 
The thyro-epiglottic ligament consists of a band of fibres that 
connect the pedicle of the epiglottis to the anterior margin of the 
angle of the thyroid cartilage, and binds the former to the latter, 
so as to retain it in the vertical position. 
[To be continued.] 
vol. xvn. 
N n 
