114 STRUCTURE OF FIBROUS TISSUK. 



separated from each other by an opake, subfibrous, intercellular net- 

 work, the breadth of the cells being considerably greater than that of 

 the intercellular structure. The cells are parent cells, containing 

 others of secondary formation, together with nuclei, nucleoli, granular 

 matter, and oil-globules in greater number than those of true car- 

 tilage. The fibres are short, imperfect, loose in texture, and yel- 

 lowish. The instances of reticular cartilage are, the pinna, epiglottis, 

 and Eustachian tube. 



Fibrous cartilage is composed of a network of white glistening 

 fibres collected into fasciculi of various size, and containing in its 



Fig. 49.* 



meshes cells and a subfibrous tissue resembling that of reticular 

 cartilage. The fibres of fibrous cartilage are identical with those of 

 fibrous tissue, the cells are large (about t 5 O th of an inch) as in reti- 

 cular cartilage, and the areolae are variable in dimensions. It is this 

 latter character that constitutes the difference between different fibrous 

 cartilages, some being composed almost entirely of fibres with few and 

 small interstices, as the interarticular cartilages, while others exhibit 

 large spaces filled with an imperfect fibrous tissue and cells, as the 

 intervertebral substance. 



The fibrous cartilages admit of arrangement into four groups, 

 namely, interarticular, stratiform, interosseus, and free. The in- 

 stances of interarticular fibrous cartilages (menisci) are those of the 

 lower jaw, sternal and acromial end of the clavicle, wrist, carpus, 

 knee, to which may be added the fibrous cartilages of circumference, 

 glenoid and cotyloid. The stratiform fibrous cartilages are such as 

 form a thin coating to the grooves on bone through which tendons 

 play. The interosseous fibrous cartilages are the intervertebral sub- 

 stance and symphysis pubis. The free fibrous cartilages are the tarsal 

 cartilages of the eyelids. 



* A portion of fibrous cartilage. The section is taken from the symphysis 

 pubis, and magnified 155 times. 



