THE SUPPORTING TISSUES. 



103 



live cartilage he explained as a mere temporary substitute 

 used to mould the shape of the succeeding bone, but as he 

 was unable to actually demonstrate his views as they are 

 now demonstrated with the microscope, they were but little 

 credited until Sharpey, in 1846, made clear beyond all ques- 

 tion the manner of the formation of bone and the replace- 

 ment of the cartilage. 



Cartilages. 



The second kind of the supporting tissues comprises 

 the cartilages, familiar under the more common name of 

 gristle. Cartilage differs from bone in the fact that the 

 cells which fill it are not branched, but smooth, and the 

 matrix does not possess a system of canals and canaliculi. 

 As a rule the mineral ingredients are much less in propor- 

 tion than in bone, although in older cartilages a calcifica- 

 tion takes place which results in giving to the cartilage as 



Fig. 46. HYALINE CARTILAGE FROM THE LOWER END OF TIBIA. (After Schafer.) 

 , 6, c, different arrangement of cell groups ; d, layer of calcified cartilage ; e, bone. 



great a proportion of earthy matter as bone possesses. 

 But such calcified cartilage is structurally entirely different 

 from bone. 



