DENTAL TISSUES. 



3C5 



wards, from its circumference, a scries of vertical plates, wliicli 

 divide into two once or twice before tliey terminate at the 

 peri])licry of the tooth. 



Each of these diverging and dichotomising plates gives off 

 throughout its course smaller processes, which stand at right 



242 



.Section of tootii of IJugong ; A, n.atura] size; It, niagilifl(?Ll ; c/, dentil 



angles, or nearly so, to the main plate ; they are generally oppo- 

 site, but sometimes alternate ; many of the secondary plates or 

 processes, which are given off near the centre of the tooth, also 

 divide into two before they terminate; and their contour is seen, 

 in the transverse section, to jjartake of all the undulations of the 

 folds of cement which invest and divide the dentinal plates and 

 processes from each other. 



The dental pulp-cavity is reduced to a mere line about the 

 upper third of the tooth, but throughout its whole extent fissures 

 radiate from it, corresponding in numljcr with the radiating plates 

 of dentine. Each fissure is continued along the middle of each 

 plate, dividing where this divides, and extending along the middle 

 of each bifurcation and process to within a short distance of the 

 line of cement. The pulp-fissure commonly dilates into a canal 



