94 LOCOMOTION. [CHAP. iv. 



OF FIBRO-CARTILAGE. 



This texture is a compound of white fibrous tissue and cartilage 

 in varying proportions. 



It is principally employed in the construction of joints, and con- 

 tributes to their perfection at once by its strength and its elasticity; 

 but as it is also, to a limited extent, used for other purposes, it may 

 be conveniently described as, 1, Articular ; 2, Non-articular. 



Fibro-cartilage, examined by the naked eye, has much of the 

 colour and general appearance of the thyroid cartilage, or of other 

 examples of the membraniform variety, which Bichat, indeed, 

 classed among nbro-cartilages. Its colour is white, with a slight 

 tinge of yellow ; it is interspersed by the shining fibres of white 

 fibrous tissue, and its appearance differs with the quantity of that 

 texture that is mingled with it. Its consistence also varies, for the 

 same reason; in some instances being extremely dense, in others 

 soft, yielding, and almost pulpy. 



When examined microscopically, fibro-cartilage is found to consist 

 of bundles of wavy fibres, with the cells or corpuscles of cartilage 

 occupying the spaces formed by the interlacement of the fibrous 

 tissue. This interlacement is often very intricate, and calculated 

 to increase the strength of the structure in those directions in 

 which the greatest toughness is required. 



Physical and Vital Properties. To the strength and density of 

 fibrous tissue, fibro-cartilage adds the elasticity of cartilage; it is 

 more variously flexible than the latter tissue, so that it will not 

 crack when bent too much. Its sensibility is low, and it is devoid 

 of vital contractility. 



Vessels and Nerves. Its vessels are few, and are derived from 

 the textures (synovial membrane or periosteum) with which it is 

 in immediate connexion. Nothing is known respecting its nerves, 

 if indeed it possess them. 



Chemical Composition. Fibro-cartilage contains water ; when 

 deprived of it by drying, it shrivels up, and becomes hard and 

 yellow. It yields gelatine in abundance on boiling. 



Forms of Fibro-cartilage. The articular fibro-cartilage is that 

 which is found most extensively, and it exists in three forms. 

 a. As discs, interposed between osseous surfaces, and equally ad- 

 herent to both, of which the intervertebral discs and the inter- 

 pubic fibro-cartilage are instances, b. As laminae, free on both 



