DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES. 497 
After the enamel-organ of m2 disappears from the serial 
sections, the dental lamina continues on, still for the most 
part in connection with the oral epithelium, and by-and-by it 
becomes swollen to form the undifferentiated Anlage of m3 
(fig. 54). In this its hinder portion the lamina preserves the 
kink or flexure above referred to, as well as the (laminar) labial 
outgrowth (/.0.) from this. The latter has, we are convinced, 
nothing to do with tooth production (cf. p. 564 et seq.). 
Lower Jaw.—In the lower jaw the dental lamina arises 
somewhat abruptly a little distance in front of the first incisor 
region. Here it is fairly thick and plump. This port on 
must be regarded as having been produced by a slight exten- 
sion forwards of the lamina since the period represented by 
Stage 111, occurring pari passu with the continued elonga- 
tion of the jaw. When the region of 7; is reached the lamina 
is seen to be continued on into a thickened residual dental 
lamina by the lingual side of 7; (fig. 55, rd/.). The enamel- 
organ of the latter is large and well developed, and is con- 
nected with the lamina by a thin epithelial connecting bridge. 
Further back the latter is lost, while the lamina itself has 
become much elongated and thinned, and here (fig. 56) is 
found attached to its neck a delicate strand of cells (cd.) 
forming a “ Verbindungsbriicke” for the small vestigial 
ealcified dt;. Only a faint trace of a dentine cap is found at 
the apex of 7, in spite of the large size of the tooth. 
Behind the first incisor region the very deep and thin lamina 
is continued on, and soon the enamel-organs of iz and i; 
appear almost simultaneously in the coronal series as a result 
of the peculiarity in the topographical relations of these teeth 
referred to in connection with the earlier stages. 7; is placed 
more superficially and labially, and it would have been impos- 
sible from an examination of this stage alone to have rightly 
interpreted the appearance presented (fig. 57). In this figure 
there will be observed a distinct labial outgrowth (diz) from 
the root of the dental lamina. Adjacent sections show it 
better as a thickened cell-mass attached to the root of the 
lamina by a thinner connecting bridge, and they also prove 
