DIGESTION OF POOD. 



287 



Fig. 238.— Incisor teeth of the horse. Details of structure (Chauveau). 1, a tooth in 

 which is indicated general shape of a permanent incisor and the particalar forms 

 successively assumed by dental table in consequence of friction and the continued 



f)U8hing outward of these teeth; 3, a virgin tooth, anterior and posterior faces; 3, 

 oneituainal section of a virgin tooth, intended to show the internal conformation 

 ana structure. Not to complicate the figure, the external cement and that amassed 

 in the infundibulum have not been exhibited; 4, transverse section for the same 

 purpose; a, encircling enamel; d, central enamel ; <;, dental star; ^, dentine; 5, de- 

 ciduous tooth. 



A tooth is made up of enamel, dentine or " ivory," and ce- 

 ment {crusta petrosa). The relative distribution of these is 

 shown in Fig, 335. 



Fig, 



239.— Transverse section of a horse's upper molar tooth (Chauveau). A, external 

 :ement; B, external enamel; C, dentine; D, internal enamel; E, internal cement. 



