CARTILAGE. 



53 



granules, fibers, or networks of elastic material, Fig. 55, B, and Fig. 56. 

 Specific elastic tissue stains are as applicable to cartilage as to connective 

 tissue, and should be used in all cases of doubt as to the nature of the fibers. 

 The elastic elements are found near the cells, but agreement has not been 

 reached as to whether they arise in the matrix or in the exoplasm. Elastic 









I. 2. 



FIG. 56. 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, capsule (?). 



cartilage occurs in the external ear and the auditory (Eustachian) tube; also 

 in the epiglottis, the cuneiform and corniculate cartilages, and the vocal 

 process of the arytaenoid cartilages, the last group being parts of the larynx. 

 Fibrocartilage, Fig. 55, C, appears as a cartilaginous modification 

 of dense connective tissue. A chondro-mucoid matrix forms among the 

 fibers, and the cells which occur singly or 

 in small groups at considerable intervals, 

 are surrounded by capsules. Fibrocar- 

 tilage is found in the intervertebral liga- 

 ments, Fig. 57, in the symphysis pubis, 

 around the mandibular and sternoclavicu- 

 lar joints, at the head of the ulna, in the 

 ligamentum teres of the hip-joint and in 

 other places associated with joints. Ves- 

 icular supporting tissue is the name given 

 to a tissue found in lower animals, resem- 

 bling precartilage, and consisting of ves- 

 icular cells with firm resistant walls. Such 

 cells may occur singly. They have been 

 described in various tendons, and in the sesamoid bone in the tendon of 

 the human peroneus longus. 



BONE. 



Bone develops relatively late in embryonic life, after the muscles, 

 nerves, vessels, and many of the organs have been formed. At this time 



\ 









FIG. 57. FROM A HORIZONTAL SECTION 

 OP THE INTERVERTEBRAL DISK. OP MAN. 



g, Fibrillar connective tissue ; z, cartilage- 

 cell (nucleus invisible) ; k, capsule 

 surrounded by calcareous granules. 

 X 240. 



