CARTILAGE. 



cartilage are more due to differences in the character of 

 the matrix than of the cells. Among the latter, however, 

 there is also considerable diversity of form and size. 



With the exception of the articular variety, cartilage is 

 invested by a thin but tough and firm fibrous membrane 

 called the pericJiondrium. On the surface of the articular 

 cartilage of the foetus, the perichondrium is represented by 

 a film of epithelium ; but this is gradually worn away up 

 to the margin of the articular surfaces, when by use the 

 parts begin to suffer friction. 



1. Cellular cartilage is not found in the human subject, 

 at least in the adult. It is composed almost entirely of 

 cells (hence its name), with little or no matrix. The 

 latter, when present, consists of very fine fibres, which 

 twine about the cells in various directions and enclose 

 them in a kind of network. The cells are packed very 

 closely together, so much so 



that it is not easy in all cases 

 to make out the fine fibres 

 often encircling them. 



2. Hyaline cartilage is met 

 with largely in the human 

 body, investing the articular 

 ends of bones, and forming 

 the costal cartilages, the nasal 

 cartilages, and those of the 

 larynx, with the exception of 

 the epiglottis and corniculd 



laryngis. Like other cartilages it is composed of cells 

 imbedded in a matrix (fig. 14). 



Fig. 14.* 



* Fig. 14. A thin layer peeled off from the surface of the cartilage 

 of the head of the humerus, showing flattened groups of cells. The 

 shrunken cell-bodies are distinctly seen, hut the limits of the capsular 

 cavities, where they adjoin one another, are hut faintly indicated. 

 Magnified 400 diameters (after Sharpey). 



