STRUCTURE OF CARTILAGE. 113 



Fig. 47, B. Fig. 47, c. 



structure. The cells are oval, oblong, or polyhedral in shape, and 

 more or less flattened ; their membranous envelope is blended with the 

 intercellular substance, and they contain in their interior secondary 

 cells, nuclei, nucleoli, oil globules, and more or less of granular matter. 

 Cartilage cells have an average measurement of lg 1 00 of an inch in 

 their long diameter ; they are sometimes isolated, sometimes grouped 

 in pairs, and sometimes disposed in a linear group of three or four. 

 They are larger near the bone than at the surface, and in the latter 

 situation are long and slender in form, and arranged in rows having 

 their long axis parallel with the plane of the surface. True cartilage 

 is pearl-white or bluish and opaline in colour, and its intercellular 

 substance is semitransparent and structureless. These characters, 

 however, are changed when it exhibits a tendency to ossify. In the 

 latter case the intercellular substance becomes fibrous and more or less 

 opake, its colour is yellowish, and the 

 cells are found to contain a greater 

 number of oil-globules than in its natu- 

 ral state. 



The true cartilages are, the articular, 

 costal, ensiform, thyroid, cricoid, ary- 

 tenoid, tracheal and bronchial, nasal, 

 meatus auris, the pulley of the troch- 

 learis muscle, and temporary cartilage 

 or the cartilage of bone previously to 

 ossification.* 



Reticular cartilage is composed of 

 cells (i/so'th of an inch in diameter) 



The section is taken from the pinna, and 



Fig. 48.t 



* Page 5. 



t A portion of reticular cartilage, 

 magnified 155 times. 



