DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES. 511 
tion of the posterior secondary cusp of iz. Both in 7; and ty 
the anterior part of the tooth is most strongly calcified. The 
former tooth has the thickest dentine cap, and it extends, 
though somewhat thinned out, practically to the posterior 
limit of the papilla of the tooth. But in 7; the dentine cap 
does not yet cover the posterior part of the papilla. In both 
teeth (¢; and i) the very large and pointed papilla is seen to 
become less pointed as it is traced backwards, until its summit 
becomes flattened, and this flattening persists in iz till the 
hinder boundary of the papilla is reached. In the case of é5, 
however, the papilla, after remaining flattened for some 
sections, quite abruptly shoots up a second pointed apex, 
which, however, at this stage is destitute of any dentinal 
covering. This second point to the papilla is merely super- 
imposed upon the massive basal part of the papilla common 
to the entire tooth, and is a mere outgrowth of the primary 
papilla. 
There are, in the incisor region of our series of Stage vil, 
considerably richer remains of the dental lamina than in 
Stage vi. Indeed, in the former there is still a very well- 
developed residual lamina beside 2;, which retains its connection 
nearly all along with the oral epithelium, and extends into the 
region of 73 and 75. 
This relative immaturity also characterises the more posterior 
teeth in the lower jaw, including dp,, the dentinal covering 
of whose papilla is much thinner than that of the same tooth 
in Stage vi. We have already seen that in respect of the 
upper jaw the present stage exhibits some anomalous features. 
The Anlage of pz is large—even bigger than in Stage vi— 
and, as in the latter, exhibits a distinct indentation with 
rudimentary papilla. 
In the molar region mz is a large enamel-organ. As in 
Stage vi the anterior cusp alone as yet is provided with a 
dentinal cap. The dentinal lamina on its lingual side is 
deeply placed and quite unconnected with the oral epithelium. 
Before it terminates posteriorly it becomes markedly thickened. 
Opposite the anterior part of the tooth it forms a residual 
