166 MICROSCOPIC ANATOMY OF THE TEETH 



enamel. In some marsupials and in the tubular enamel of 

 Hyrax the calcification is more complete in this situation, 

 and the dentinal tubes pass into the enamel without showing 

 any spaces or apparent enlargements. These spaces have 



P 



FIG. 96. Developing tooth of Macropus (cut without decalcification). 

 e. Enamel ; s. area of incomplete calcification ; d. calcified dentine ; 

 d'. odontogenic zone ; o. odontoblasts ; p. pulp. In several places the 

 dentinal tubes are seen passing into the area s. ( x 800.) 



been previously referred to on p. 81, and this view of their 

 causation agrees in the main with those of Von Ebner and 

 Pickerill. 



If, at the first formation of the dentine, the dentinal fibril 

 passes into the organic substance of the enamel, and a con- 

 nexion is thus established between the cells of the dentine 



