66 



SIXTH LECTURE. 



side by side and against each other. The calcification of the 

 cartilage spreads peripherically ; the liquefaction and re-forma- 

 tion of the cartilage canals is constantly increasing in extent, 

 and likewise in the domain of the calcified cartilage. 



Fig. 63. — Ossifying border of a phalangeal epiphysis of the calf, in vertical section. At the uppei 

 part, the cartilage, with its irregularly disposed capsules, containing daughter cells ; a, smaller 

 medullary spaces, appearing in part as though closed, drawn" empty ; £>, the same with narrow cells ; 

 c, remains of the calcified cartilage ; d, larger medullary spaces, on the walls of which are depo- 

 sitions of thinner or thicker bone tissue, and in the latter case stratified; e, developing bone cell ; 

 /, an opened cartilage capsule, with an embedded bone cell ; g; a partially filled cavityv covered 

 externally with bone substance and containing a narrow cell; //, apparently closed cartilage capsules 

 containing bone cells. 



The latter must naturally first become physiologically 

 decalcified before undergoing solution. This removal of a but 

 just deposited lime salt is, up to the present time indeed, 

 somewhat enigmatical. 



Let us look at Fig. 63. At the upper part, the cartilage 



