674 THE TEETH. 



break down into medullary corpuscles, from which arises the 

 well-known graceful myxomatous tissue. This tissue again 

 returns to the medullary condition before producing enamel, 

 the process being identical to that by which dentine is produced. 

 Dentine is formed of medullary corpuscles, which are arranged 

 in rows at the periphery of the papilla/ and which afterward 

 change into the glue-yielding basis-substance, the seat of infil- 

 tration, with lime-salts. The canaliculi of the dentine are formed 

 between the medullary corpuscles, and the dentinal fibers arise 

 from a coalescence of the living matter which is present between 

 the medullary corpuscles, termed " odontoblasts." 



