CEMENT 293 



The cement appears to be in contact with the granular 

 layer of the dentine (fig. 184), but a clear layer often, but 

 not always, intervenes. It is sometimes described as 

 a structureless layer of dentine, sometimes as cement. 

 In figs. 184, 185, and 186, the granular layer is seen in 

 immediate contact with the cement, and the fine terminal 

 branches of the dentinal tubules are continuous with the 

 canaliculi. This condition is also seen in many of the 



Y 



Fia. 187. Communication of dentinal tubes with cells of granular layer 

 and with canaliculi of the cement, c. Cement ; d. dentine ; g. granular 

 layer. (Human molar. ) ( x 150.) 



author's preparations of human teeth. The majority of 

 the canaliculi are directed towards the outer surface (figs. 

 187, 188, and 189. Many appearances suggest that the outer 

 layer consists of the first-formed cement, but it is very 

 difficult to speak with any certainty on the point (see figs. 

 186 and 190). 



The lacunae and their canaliculi are scattered or arranged 

 in rows ; they are much more irregular in form than the 

 lacunae of bone, and often have a tufted appearance, and 

 the canaliculi are frequently seen in the roots of teeth 

 extending across several lamellae and of great length. In 

 irregularly deposited cement some of the lacunae have no 

 apparent canaliculi ; these are the bodies which Hope well 



