CARTILAGE. 53 



ment about the cells, and in their general characters are 

 allied to the yellow variety of fibrous tissue (fig. 15). 



White fibro-cartilage, which -p. * 



is much more widely distri- 

 buted throughout the body 

 than the foregoing kind, is 

 composed, like it, of cells and 

 a matrix ; the latter, however, 

 being made up almost entirely 

 of fibres closely resembling 

 those of white fibrous tissue. 



In this kind of fibro-car- 

 tilage it is not unusual to find a great part of its mass 

 composed almost exclusively of fibres, and deserving the 

 name of cartilage only from the fact that in another por- 

 tion, continuous with it, cartilage cells may be pretty freely 

 distributed. 



The different situations in which white fibro-cartilage is 

 formed have given rise to the following classification : 



1. Inter-articular fibro-cartilage, e.g., the semilunar car- 

 tilages of the knee-joint. 



2. Circumferential or marginal, as on the edges of the 

 acetabulum and glenoid cavity of the scapula. 



3. Connecting, e.g., the inter- vertebral fibro-cartilages. 



4. Fibro- cartilage is found in the sheaths of tendons, 

 and sometimes in their substance. 



The uses of cartilage are the following ; in the joints, to 

 form smooth surfaces for easy friction, and to act as a 

 luffer, in shocks; to bind bones together, yet to allow a 

 certain degree of movement, as between the vertebrae ; to 

 form a firm framework and protection, yet without undue 

 stiffness or weight, as in the larynx and chest walls ; to 

 deepen joint-cavities, as in the acetabulum, yet not so as 



* Fig. 15. Section of the epiglottis, magnified 380 diameters (Dr. 

 Baly), 



