CHAPTER XX 



THE ROOTS OF TEETH 



Evolutionary importance of the roots — Paleotelic and caeno- 

 telic Characters — Features of the root in mammalian teeth — 

 Nature's methods of combating attrition — Inferences from 

 the deep-seated position of the canine root in Man — The 

 roots of teeth in Man and Anthropoids — Specialized roots of 

 teeth in the Aye-aye — Roots of teeth in Neandertal Man. 



During his perusal of the foregoing chapters the reader must 

 have been impressed by the fact that practically the entire dis- 

 cussion has related to modifications of the cusps and crowns of 

 teeth. He will have observed the wide range of adaptation of 

 the cheek teeth to changes in habit and the profound bearing 

 upon the whole dentition of the form of the incisors but he is 

 justified in asking why roots have received such scant mention. 

 It will of course be quite evident that the exposed crowns 

 from their very position must command attention whereas the 

 roots buried in the jaws are less accessible. Nevertheless it 

 is equally apparent that study of the roots must have its im- 

 portance in adequate consideration of the dentition as a whole. 

 It might even be argued that the roots are at least as impor- 

 tant as the crowns because of the fact that being imbedded in 

 the jaws they are less influenced than the crowns by modifica- 

 tions of environment. That they are not entirely unaffected by 

 environmental changes is sufficiently indicated however by 

 the frequent transformation in many orders of the brachyodont 

 into the hypsodont type of tooth. 



In this connection the student should understand the dif- 

 ference between paleotelic and caenotelic characters. These terms 



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