FIG. 215. Root tip at later stage. Shortening of the epithelial sheath. 

 o. Osteoblasts ; h 1 . Hertwig's sheath ; h 2 . Hertwig's sheath in contact with 

 the dentine ; d. dentine ; p. pulp, (x 150.) 



FIG. 216. Root tip at still later stage. Involution of Hertwig's sheath 

 much shortened, o. Osteoblasts and osteoclasts in forming cement ; 

 h 1 . Hertwig's sheath in contact with dentine ; h 2 . termination of sheath 

 in pulp (p.). (x!50.) 



