THE LUNGS. 161 



contents, of a peculiarly compact, and, at the same time, elastic 

 structure. 



§173. 



The larynx is the most complex portion of what are termed 

 the air-passages, and consists, in the first place, of a firm 

 framework, the cartilages of the larynx, together with their 

 ligaments; secondly, of numerous small muscles attached to 

 them ; and lastly, of a mucous membrane, abounding in glands, 

 with which they are lined. 



The cartilages of the larynx are not all alike in their struc- 

 ture, some being composed of common cartilaginous tissue, 

 others of fibro-cartilage, whilst others, again, are constituted of 

 the so-termed reticular or yellow cartilage. To the former 

 belong the thyroid-, cricoid-, and arytenoid-cartilages ; all of 

 which present a more homogeneous, hyaline matrix, with scat- 

 tered cartilage cells imbedded in it (fig. 20), and approach 

 nearest to the costal among the other true cartilages. Most 

 externally they contain flattened cells, to which succeeds a 

 whitish layer, with numerous large parent-cells and a more 

 fibrous fundamental substance ; and, lastly, in the interior, a 

 larger proportion of matrix and minute radiating cavities. 

 The membranes of the cells are thickened, and, in their in- 

 terior, a large oil-drop is most usually found. Incrustations 

 of the cartilage-cells and of the matrix, with minute cal- 

 careous granules, are very frequent in the laryngeal cartilages ; 

 but besides these, true ossifications occur, which are always 

 attended with the formation of larger cavities, filled with a 

 well-marked, gelatiniform, vascular medulla. The epiglottis 

 and the cartilages of Santorini and of Wrisberg, consist of 

 yellow or reticular cartilage (vide § 22, fig. 21), presenting 

 opaque, very closely interlaced fibres, which, in animals (e. g. 

 the Ox), are much thicker than in Man, and clear cells, 0-01 

 — O'C^'" iu size, in which Henle, in one instance, noticed a 

 concentric disposition of such a kind that the remaining cavity 

 of the cell resembled a simple bone-lacuna with a few pro- 

 longations (Allg. Anat., Tab. V, fig. 8). The cartilago triticea 

 consists of connective tissue with scattered cartilage-cells, and 

 is, consequently, common fibro-cartilage. 



Of the ligament of the larynx, the ligg. crico-thyreoideum 



ii. 11 



