THE DEVELOPMENT OF THE TEETH. 131 



pended from above by the thin cord of epithelium which 

 still connects it with the epithelium of the surface, or it 

 might in section be described as crescentic, the horns of the 

 crescent being long, and looking downwards. Coincident 

 with the assumption of this form by the enamel germ, is 

 the appearance of the dentine germ ; but it will facilitate 

 the description of the process to pursue a little farther 

 the development of the enamel organ. 



The cells on its periphery remain prismatic or columnar, 

 but those in its centre become transformed into a stellate 

 network, in which conspicuous nuclei occupy the centre of 

 ramified cells, the processes from which anastomose freely 

 with those of neighbouring cells (see Fig. 65). This conver- 

 sion of the cells into a stellate reticulum is most marked 

 quite in the centre of the enamel organ ; near to its surfaces 

 the processes of the cells are short and inconspicuous. 



The transformation of the cells occupying the centre and 

 constituting the bulk of the enamel organ into a stellate 

 reticulum goes on progressing from the centre outwards, but 

 it stops short of reaching the layer of columnar cells which 

 constitute the surface of the enamel organ, next to the den- 

 tine papilla ; a narrow layer of unaltered cells which remain 

 between the stellate cells and the columnar enamel cells 

 constituting the " stratum intermedium." 



Thus far the cells constituting the periphery of the 

 enamel organ are alike : they are columnar or prismatic, 

 but from the time of the appearance of the dentine papilla 

 those which come into relation with it become much more 

 elongated and greatly enlarged, while those round the outer 

 or convex surface of the enamel organ do not enlarge ; 

 indeed, according to some authors, they even commence to 

 atrophy even at this early period. The cells which lie like 

 a cap over the dentine germ or "papilla" as they elongate 

 and their nuclei recede to their extremities, take on the 

 character to be presently described as belonging to the 



K 2 



