TOOTH-GERMS IX A WALLABY. 



929 



growths which could serve as an indication as to which dentition 

 the germs should be referred. 



As this tooth is traced backwaixls it assumes a peculiar shape on 

 section. Its inner margin is sharp, the outer one rounded, while 

 on the dorsal svirface is a relatively deep fissure (text-fig. 182). 



The peculiarity of the adult tooth is thus early indicated. 



As ^disappears from the sections a new tooth-germ (0) makes 

 its appearance. Though minute it has a fully formed enamel 

 organ and dental papilla, but without any trace of calcification. 

 This germ has a very superficial position in the jaw. 



Closely following upon C is a large uncalcified tooth (B) Ij^ing 

 to the palatal aspect of and slightly posterior to the preceding 

 tooth-germ. Connected with the neck of the enamel organ is a 

 minute predecessor slightly invaginated by a rudimentary dental 

 papilla (text-fig. 183). 



Text-fiff. 183. 



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Section showing the tooth-geiin D with its predecessor lying to the labial side 

 of the neck-band. 



Yet another germ (F) of some size soon makes its appearance, 

 occupying a superficial position in the jaw. There is a slight 

 bulging of, the dental lamina to the labial side of the neck of this 

 enamel organ, which may or may not indicate an abortive attempt 

 at the formation of a predecessor. 



The dental lamina from this point is continued backwards for 

 some distance as a distinct band without showing any definite 



