76 A MANUAL OF DENTAL ANATOMY. 



Ordinary hard dentine has been sufficiently described ; of 

 it plici-dentine is a variety not very distinct in its essential 

 nature, though at first sight widely dissimilar. 



Plici-dentine. In ordinary dentine the dentinal tubes 

 radiate out from a pulp and pulp chamber of simple form ; 

 render complex that form by foldings of its walls, the den- 

 tinal tubes still running off at right angles to that portion 

 of pulp to which they immediately belong, and we have 

 a " plici-dentine." It is merely an ordinary dentine and its 



Fio. 36 ( 1 ). 



pulp folded up and wrinkled into a greater or less degree 

 of complexity. 



In the teeth of the Varanus (monitor lizard) the process of 

 calcification of the pulp takes place in such manner that in 

 the upper half of the tooth a cap of ordinary unvascular 

 dentine, in which the tubes radiate from a single central 



( 1 ) Section of Plici-dentine with the pulp in situ (Lepidosteus). 

 c. Odontoblasts. p. Connective tissue framework of pulp. d. Dentine. 



