DEVELOPMENT OF THE ENAMEL 



123 



in human tooth germs is in many places not continuous, 

 but shows numerous indentations and interruptions, and 

 the blood-vessels of the capsule are in actual contact with 

 the cells of the stellate reticulum (see fig. 70). They also 

 showed that epithelial buds arise from the outer surface of 

 the external epithelium and proliferate within the follicle, 

 as shown in fig. 72 (photographed by the author from 

 a preparation by Warwick James). 

 Malassez says, ' This ' (the external layer of the enamel 





FIG. 71. Blood-vessels penetrating the external epithelium and entering 

 the stellate reticulum in Macropus rufus. ( x 125.) 



organ) ' does not form everywhere and always a continuous 

 investment, as is generally thought. One sees in it, in certain 

 regions, numerous lacunae or windows which give it the 

 appearance of an epithelial network.' 



The papillary projections into the external layer of the 

 enamel organ, first described by Herrissant (14), were sup- 

 posed by him to be charged with the function of secreting 

 the enamel. They no doubt represent these vascular pro- 

 longations described by Malassez, and probably serve to 

 convey a blood supply to the stellate reticulum, but there 

 is no evidence that they have any directing influence on 

 the enamel prisms as some authors have imagined. 



