4.66 J. T. WILSON AND J. P. HILL. 
transverse (coronal) section of the same region.! The back- 
ward recurvature of this small labially projecting cell-mass, 
seen in fig. 18, must not be mistaken for an indication of com- 
mencing papillation from behind forwards. The series of sec- 
tions proves that the projection in question is simply being 
gradually pinched off from the main body (22). Higher up, 
the horizontal sections show only the two lobes of the Anlage 
of i2 (d/2 and ‘‘22”’), It will presently appear that all these 
features are still better marked in connection with the region 
of the third incisor, which is partly illustrated in the same 
drawing (fig. 18, “ III’). 
Horizontal sections taken at a lower level than fig. 18 show 
the dental lamina (d/2) in the region of the second incisor to 
be prolonged backwards into continuity with d/3 in the third 
incisor region. 
Horizontal sections passing through the upper part of the 
third incisor-mass closely resemble those through the upper 
part of the second—viz. in each case we have lingually the 
lobe formed by swollen dental lamina, and labially the lobe 
formed by the differentiating labial moiety of the incisor 
Anlage. As in the cases of the two more anterior tooth- 
germs, the two lobes are separated by a slight groove or 
sulcus, and, corresponding to this, over the summit of the 
Anlage the connective tissue shows a slight cellular aggrega- 
tion indicating the commencement of the dermal papilla. 
Horizonal sections taken a little lower down begin to show 
a narrow labial projection in a position corresponding to that 
of di2 in the second incisor region. Still lower there suddenly 
appears, closely external to the last-named outgrowth, an 
isolated mass of epithelial cells. In sections taken still more 
inferiorly, as shown in fig. 18, “III,” this cell-mass (d73) is 
found to be really connected with the labial aspect of the main 
mass of 72 by a narrow neck (cb.). This labial cellular out- 
1 The single coronal section here figured might seem to suggest that the 
di% projection simply forms the lower limit of a papillated depression on the 
labial aspect. This is a merely accidental resemblance, as a study of the 
neighbouring sections in the series amply proves. 
