OP THE CARTILAGES IN GENERAL. 345 



several of them, at least ossify, sometimes even at the end 

 of the period of growth. The temporary cartilages will be 

 described along with the bones, (chap, viii.) We shall treat 

 here only of the cartilages called permanent: they form a 

 very natural genus of organs, and present also some differences. 



SECTION I. 



OF THE CARTILAGES IN GENERAL. 



542. Some cartilages have an elongated form : such are 

 the cartilages of the ribs ; others are thick and short, like the 

 arythenoid and cracoid cartilages; but the greater number are 

 broad and thin. 



Some are attached to the bones of which they cover certain 

 parts; others are prolongations of them and are firmly united 

 to them; others are connected to the bones by ligaments; 

 others are attached to each other, and have no other connexions 

 with the bones. 



The cartilages are of a pearly white, and semi-transparent 

 when in their laminae; although they are the hardest parts of 

 the body after the bones, they are easily cut. 



543. The cartilages, when examined in their substance, 

 present neither cavities, nor canals, nor areolae, nor fibres, 

 nor laminae, finally, nothing that indicates an organic texture; 

 they appear homogeneous. It seems, however, that they have 

 a distinct and different kind of texture in each species of carti- 

 lage: this assertion will be investigated hereafter. 



All the cartilages, with the exception of those of the articu- 

 lar surfaces, are enveloped in a fibrous membrane, the peri- 

 chondrium, whicli has few vessels, and is not so intimately 

 connected with the cartilages as the periosteum is with the 

 bones. Neither nerves nor vessels have ever been discovered 

 in the cartilages; the cellular tissue is not apparent during life, 

 and after death they require to be macerated during several 

 months, even with young subjects, to reduce them to a mu- 



