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CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 
face ; and their internal surface forms the superior angle of the 
chink of the larynx. In structure they are distinctly fibro-carti- 
laginous at their base, and at their apex they contain a considerable 
quantity of the yellow elastic tissue. A considerable number of mu- 
cous crypts are also contained in them along their internal margins, 
and, giving rise thereby to the appearance of a glandular structure, 
they have been named, though improperly, “the arytenoid glands." 
The epiglottis is the fibro-cartilaginous valve situated at the base 
of the tongue, and covering the entire entrance or superior aperture 
of the larynx. In its usual direction it is vertical ; but, during the 
act of deglutition, it becomes horizontal. In the horse it consists 
of three portions — a body and two appendages. The body has 
somewhat the appearance of a cordate leaf, the pedicle being at- 
tached to the inner surface of the angle of the thyroid cartilage, 
and the base, slightly convex and drawn to a point, is free, and 
projects above the surface of the base of the tongue. The anterior 
surface is convex, and connected to the base of the tongue and 
the os hyoides by a dense band of yellow elastic fibres and the 
hyo-epiglottideus muscle. Its posterior, or laryngeal surface, is 
covered by the mucous membrane, and presents the openings of 
numerous mucous follicles that apparently perforate its substance 
to open on this surface. In structure it is fibro-cartilaginous, 
especially in the centre ; but towards the edges, and in its pedicle, 
it contains also a considerable quantity of the yellow elastic tissue. 
The appendages, or cornua, of the epiglottis are situated on 
either side of the epiglottis, near to its point of attachment to the 
thyroid cartilage. They are inclosed between the layers of the 
anterior or false vocal chords, for about one-half of their extent ; 
and their apices are connected to the sides of the arytenoid carti- 
lages, near their points, by a broad band of elastic fibres. In 
structure they are fibro-cartilaginous, with an abundance of the 
yellow elastic tissue, and they also contain numerous mucous 
crypts in their substance. In function they would seem to serve 
as links of connexion between the epiglottis and the arytenoid 
cartilages, and they will also tend to keep open and expanded the 
ventricles of the larynx, the anterior and inferior boundary of 
which they form. 
The Articulations of the Larynx. 
The articulations of the larynx may be arranged under two sets, 
an extrinsic and an intrinsic ; the former embracing those that 
connect the thyroid cartilage and epiglottis to the os hyoides, and 
the cricoid to the first ring of the trachea ; and the latter, all those 
