486 



MOVEMENTS VOICE AND SPEECH. 



regenerated. The importance of the 

 periosteum has been still farther illus- 

 trated by the experiments of Oilier 

 and others, upon transplantation of 

 this membrane in the different tissues 

 of living animals, which has been fol- 

 lowed by the formation of bone in 

 these situations. 



Physiological Anatomy of Carti- 

 lage. In this connection the structure 

 of the articular cartilages presents the 

 chief physiological interest. The ar- 

 ticular surfaces of all the bones are 

 Fi G .m.-section of cartilage from the rib of the encrusted with a layer of cartilage, 



ox, showing the homogeneous fundamental varvinrr in +Viir>Vnp V>ptwppn 1 cmrl 



substance, car tit ac,e - cavities and cartilage- Var ) m 5 X * W a 



cells; magnified 370 diameters (from a photo- 1 /->f an inpn (0-^ anrl 1 mm ^ Tlio 



graph taken at the United States Army Medical 25 



Museum). cartilaginous substance is white, opal- 



ine, and semi-transparent when examined in thin sections. It is not 

 covered with a membrane, but in the 

 non - articular cartilages it has an 

 investment analogous to the perios- 

 teum. 



Examined in thin sections, cartilage 

 is found to consist of a homogeneous 

 fundamental substance, marked with 

 excavations, called cartilage-cavities or 

 chondroplasts.' The intervening sub- 

 stance has a peculiar organic constitu- 

 ent, called chondrine. The organic 

 matter is united with a certain propor- 

 tion of inorganic salts. This funda- 

 mental substance is elastic and resist- 

 ing. The cartilages are closely united 

 to the subjacent bony tissue. The 

 free articular surface has already been 

 described in connection with the syn- 

 ovial membranes. 



Cartilage- Cavities. These cavities 

 are rounded or ovoid, measuring ygVir 

 to ^J-j of an inch (20 to 80 p.) in diam- 

 eter. They are generally smaller in 

 the articular cartilages than in other 

 situations, as in the costal cartilages. 

 They are simple excavations in the 

 fundamental substance, have no lining 

 membrane, and they contain a small 



1. 1, osseous tissue ; 2, 2, superficial layer of osse- 

 ous tissue treated with hydrochloric acid; 3, 

 cavities and cells of the deep layer of carti- 

 4, 4, cavities and cells of the middle lay- 



ial 



, , 

 er : 5. 5, cavities and cells of the superfic 



layer. 



