318 



THE TISSUES. 



As cartilage contains no vessels, very slight nutritive changes 

 probably occur, after it once attains to its full development. 



Cartilage, if removed, is never regenerated. White fibrous tis- 

 sue is developed instead, to fill up the breach; or a cretification of 

 the entire cartilage may take place. (Dr. Eedfern.) The costal car- 

 tilages, if fractured, are, however, repaired by osseous union. These 

 cartilages are normally ossified in some of the lower animals, and 

 are not seldom ossified in the latter period of life, in the human 

 subject. 



Articular cartilages are, in the foetus, covered by an epithelium. 

 This appears to be destroyed after birth by pressure and attrition. 

 While it exists, vessels are found between it and the cartilage; and 

 which subsequently return to the circumference of the latter. Their 

 appearance before and after birth is shown by Figs. 205 and 206. 



Fig. 205. 



Vessels situated between the attached synovial membrane and the articular cartilage, at the point 

 where the ligamentum teres is inserted in the head of the os femoris. Human foetus between 3 and 

 4 months, a. The surface of the articular cartilage. 5. The vessels between the articular cartilage 

 and the epithelial layer, c. The surface to which the ligamentum teres was attached, d. The vein. 

 e. The artery. 



Their connection with the bones will be explained in the following 



chapter. 



Fig. 206. In the costal cartilages, vas- 



cular canals are found at large 

 distances from each other, and 

 which are lined by prolonga- 

 tions of their perichondrium, 

 and narrow cartilage-cells. The 

 vessels, however, nowhere pass 

 from the walls of those canals 



Vessels with varicose dilatations surrounding the , .1 -i , n ,1 



edges of the articular cartilages, after birth. in tO the Substance of the Car- 



