Fig. 16 Longitudinal section of upper incisor of 2-day albino rat showing 
the enamel-organ continuous over the labial surface and terminating posteriorly 
in the thickened margin. X 18. 
Fig. 17 Small portion of preceding figure more highly magnified, to show 
the structure of the enamel-organ and the odontoblasts. a, outermost layer 
of enamel-organ and epithelial papillae; b, enamel pulp; c, stratum intermedium; 
d, layer of ameloblasts; e, layer of dentine; f, layer of odontoblasts. 175. 
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