CARTILAGE 



8l 



arise from the cells, but according to Schafer "their formation apart 

 from the cells can be easily verified in the arytaenoid cartilage of the calf." 

 The elastic nature of fibers within the cartilage matrix can be demon- 

 strated by special stains, such as resorcin-f uchsin ; they stain like the elastic 

 fibers of connective tissue. 



2. 



FIG. 68. ELASTIC CARTILAGE. X 240. 



i, Portion of a section of the vocal process of an arytaenoid cartilage of a woman thirty years old; the elastic 

 substance is in the form of granules. 2 and 3, Portions of sections of the epiglottis of a woman sixty 

 years old; a fine network of elastic fibers in 2, a denser network in 3. z, Cartilage-cell, nucleus invisible; 

 k, transparent capsule. 



Fibro-cartilage cannot be regarded, like elastic cartilage, as a late modi- 

 fication of hyaline cartilage. In its early development, as seen in the 

 intervertebral disc of an embryo, its matrix is primarily fibrous. It is 

 composed of anastomosing bundles of fibers which blend with the hyaline 

 matrix of the adjacent vertebral cartilage as shown in Fig. 66, B. Instead 

 of becoming transformed into hyaline 

 cartilage, however, it develops into a 

 cartilaginous modification of dense con- 

 nective tissue. It is found typically de- 

 veloped in the intervertebral and inter- 

 pubic fibro-cartilages. According to Stohr 

 it forms the articular cartilage lining the 

 sterno-clavicular, acromio-clavicular, and 

 mandibular joints, together with the joints 

 of the costal cartilages, and it covers the 

 head of the ulna. Usually it is said to 

 form the rims deepening the sockets of the 

 shoulder and hip joints, together with the 

 interarticular discs of the mandibular, 

 sterno-clavicular and knee joints but these, according to Stohr, consist of 

 dense connective tissue without the characteristic cartilaginous matrix. A 

 portion of their cells are round, however. Even when typically developed, 

 fibro-cartilage consists chiefly of interwoven bundles of white fibers 

 With hasmatoxylin and eosin this ground substance is diffusely stained, 

 since the fibers, colored by the eosin, are imbedded in a chondro-mucoid 



A 



FIG. 69. FROM A HORIZONTAL SECTION 

 OF THE INTERVERTEBRAL Disc OF MAN. 



gf, Fibrillar connective tissue; z, cartilage- 

 cell (nucleus invisible); k, capsule 

 surrounded by calcareous granules. 

 X 240. 



