DEVELOPMENT OF THE TEETH. 



481 



The above account differs from that which I formerly gave, 

 in recognising a dental groove in the vicinity of the subsequently 

 appearing dental rudiment, and in not regarding this groove as a 

 secondary formation caused by an hypertrophy of the epithelium. 

 Ko Hiker (58) also describes a groove of this nature, and figures it 

 with the enamel germ proceeding from its deepest part.* The state- 

 ments of Marcusen (31) on the development of the teeth, which I 



Fig. 101. 



Fig. 101. Vertical section of the inferior maxilla of a human foetus, 

 measuring eleven centimeters from the vertex to the coccyx. Magnified 

 25 diameters. 1. Dental groove. 2. Remains of the enamel germ. 

 3. Enamel organ presenting externally epithelium, as also where it 

 forms the enamel germ of the papillse of the dental sacculus. 4. Secon- 

 dary enamel germ ; rudiment of the permanent tooth. 5. Dental germ. 

 6. Lower jaw. 7. MeckeFs cartilage. 



have already indicated as being the first that were accurate (49), 

 require still to be followed out in further detail. Dursy (67) has very 

 recently entered minutely into the description of the first occurrence 

 of the dental groove, and has accompanied his statements with nu- 

 merous illustrations. He considers it to be formed by an inequality 

 in the growth of the margin of the jaw. He regards the enamel germ 

 as resulting from the progressive development of the dental furrow 

 and its epithelium, which, however, does not penetrate more deeply 



* Loc. tit., fig. 260. 



