BOOK I. 



PART III. 



CHAPTER I. 



ARTICULATIONS. 

 OF THE CARTILAGINOUS SYSTEM. 



CARTILAGES (Cartilagines, Systkme Cartilagineux,) supply the 

 place of bone in many parts of the human skeleton, as in the 

 space between the ribs and sternum, in the larynx, in the ex- 

 ternal ear, in the nose, and elsewhere. They are also to be 

 found in all the moveable, and in several of the immoveable ar- 

 ticulations. Wherever placed they may be recognised by their 

 whiteness, by their flexibility, by their great elasticity, and by 

 a hardness only short of that of the bones. There are many ani- 

 mals whose skeletons are .entirely cartilaginous, as the chon- 

 dropterous or cartilaginous fishes, so excellent a substitute is 

 cartilage for bone. 



Cartilages have neither canals nor cells in them. They appear 

 homogeneous; and, upon a superficial inspection, present neither 

 laminas nor fibres. The immersion of them in boiling water 

 dissolves into a jelly, such as are found upon the articular sur- 

 faces of the bones, and a few others ; but, such as supply the 

 place of bone, though softened by the process, are not rendered 

 by any means so gelatinous. Their chemical analysis, accord- 

 ing to Mr. I. Davy, is gelatine, 44.5; water, 55.; phosphate of 

 lime, 0.5. The testimony of different experimenters, upon the 

 latter point, does not coincide, and their results must vary ac- 

 cording to the kind of cartilage, and the period of life. 



Cartilages are composed of a tissue exclusively their own, 



