The larynx is remarkable for its great length and mobility. The
cartilages are more loosely attached to each other than in the other
animals. The =cricoid cartilage= is thick and compressed laterally; its
lamina is long and narrow; its arch is directed obliquely downward and
backward. The =thyroid cartilage= is very long; its laminæ are united
ventrally and form a median ridge. The anterior cornua being absent,
there are no joints formed with the hyoid bone. The posterior cornua are
broad, bent inward, and articulate with the cricoid cartilage. The
=epiglottis= is relatively very large, and is more closely attached to
the hyoid bone than to the rest of the larynx. The middle part of its
base is turned forward, and rests on the thyro-hyoid membrane; it is
closely connected with the body of the hyoid bone by the hyo-epiglottic
ligament and the strong hyo-epiglottic muscle.[134] The apex of the
=arytenoid cartilage= is very large, and is divided into two parts at
its extremity; the inner part is fused with that of the opposite
cartilage. There is a small =interarytenoid cartilage= in the transverse
ligament. The =rima glottidis= is very narrow. The =vocal cords= are
directed obliquely downward and backward; and each is pierced by a long,
slit-like opening, which leads into the large laryngeal saccule. The
thyro-arytenoid or vocal ligament is similarly divided into a larger
anterior and a smaller posterior part. There is a middle ventricle near
the base of the epiglottis. The thyro-arytenoid muscle is very strong
and is undivided. The arytenoideus is very small. The crico-thyroid
consists of two strata; the superficial layer corresponds to the muscle
of the other animals; the deep part consists of transverse fibers.