488 MOVEMENTS. 



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 numerous, but are 

 rounded and quite large. The cells contain generally a 

 certain amount of fatty matter. The appearance of the or- 

 dinary articular cartilage is represented in Fig. 20. 



The ordinary cartilages have neither blood-vessels, lym- 

 phatics, nor nerves, and are nourished exclusively by imbibi- 

 tion from the surrounding parts. Their function has already 

 been sufficiently considered in treating of the synovial mem- 

 branes. In the development of the body, the anatomy of 

 the cartilaginous tissue possesses peculiar interest, from the 

 fact that the deposition of cartilage precedes the formation 

 of bone ; but we have here only to do with the permanent 

 cartilages. 



Fibro-Cartilage. This variety of cartilage presents cer- 

 tain important peculiarities in the structure of its funda- 

 mental substance. It exists in the synchondroses, the car- 

 tilages of the ear, of the Eustachian tabes, the interarticular 

 disks, the intervertebral cartilages, the cartilages of Santorini 

 and of Wrisberg, and the epiglottis. Its structure has been 

 very closely and successfully studied by Sappey, who has 

 arrived at results differing considerably from those obtained 

 by other observers. 



According to Sappey, 1 the fibre-cartilage is composed of 

 true fibrous tissue with a great predominance of elastic fibres, 

 fusiform, nucleated fibres, a certain number of adipose vesi- 

 cles, cartilage-cells, and numerous blood-vessels and nerves. 

 The presence of cartilage-cells assimilates this tissue to the 

 ordinary cartilage, though its structure is very much more 

 complex. The fibrous elements above mentioned take the 

 place of the homogeneous fundamental substance of the true 

 cartilage. The most important peculiarity in the structure 

 of this tissue is that it is abundantly supplied with blood- 

 vessels and nerves. 



1 SAPPEY, Traite tfanatomie, Paris, 1867, tome i., p. 458, et seq. 



