PASSIVE ORGANS OF LOCOMOTION 



433 



the articular cartilages than in other situations, as in the costal carti- 

 lages. They are simple excavations in the fundamental substance, 

 having no lining membrane, and they contain a small quantity of a 

 viscid liquid with one or more cells. They are analogous to the lacunae 

 of the bones. 



Cartilage-cells. Near the surface of the articular cartilages the 

 cavities contain each a single cell ; but in the deeper portions the cavi- 

 ties are long and contain two to 

 twenty cells arranged longitudi- 

 nally. The cells are about the 

 size of the smallest cavities. They 

 are ovoid, with a large granular 

 nucleus. They often contain a few 

 small globules of oil. In the costal 

 cartilages the cavities are not abun- 

 dant but are rounded and quite 

 large. The cells contain usually 

 a certain quantity of fatty matter. 

 The appearance of the ordinary 

 articular cartilage is represented 

 in Figure 89. 



The ordinary cartilages have 

 neither bloodvessels, lymphatics 

 nor nerves, and are nourished by 

 imbibition from the surrounding 2i 

 parts. In the development of the 

 body, the anatomy of the cartilagi- 

 nous tissue possesses peculiar im- 

 portance, from the fact that the 

 deposition of cartilage, with a few 

 exceptions, precedes the formation 



of bone (see Plate X, Fig. 3). *. *. osseous tissue; 2, 2, superficial layer of 



j^j /^ / T-I . osseous tissue treated with hydrochloric acid ; 



hlastlC Cartilage. This Variety 3i 3> cavit ies and cells of the deep layer of car- 



Of Cartilage presents Certain im- tiIa S e S 4, 4. cavities and cells of the middle layer ; 



. . 5, 5, cavities and cells of the superficial layer. 



portant peculiarities in the structure 



of its fundamental substance. It exists principally in the cartilages of 

 the ear and of the Eustachian tubes, the cartilages of Santorini and of 

 Wrisberg and the epiglottis. Elastic cartilage is composed of fibrous 

 tissue with a great predominance of elastic fibres, fusiform nucleated 

 fibres, a certain number of adipose vesicles, cartilage-cells, bloodvessels 

 and nerves. The fibrous elements above mentioned take the place of the 

 homogeneous fundamental substance of ordinary cartilage. The most 



Fig. 89. Vertical section of diar thro dial cartilage 

 (Sappey). 



