DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES, 518 
boundary of a cupped depression filled with connective-tissue 
cells. The whole Anlage is surrounded by an envelope of con- 
densed connective tissue, and is separated by a bony lamella 
from the overlying hinder part of p2. No drawing is given, 
but the condition may be understood by reference to fig. 67 
(Stage 1x) and fig. 73 of Stage x. The deciduous premolar 
persists in the sections for some distance behind the point of 
disappearance of p? and beneath the rapidly enlarging m+. 
In the region of the first two molars traces of the dental 
lamina persist, sometimes as small irregular groups of epithelial 
cells, and sometimes as large and rounded “ epithelial pearls.” 
The lamina, however, assumes more definite form posteriorly 
opposite the hinder end of m2. 
The third molar is still very much in the condition it ex- 
hibited in the immediately preceding stages (fig. 69), i.e. it 
shows commencing papillation, somewhat more marked than 
formerly ; but the more superficial (more proximal) part of 
the lamina now exhibits a number of irregularities in place of 
the simple labial projection corresponding to the root of the 
laminar connection for m2. These irregularities are secondary 
developments, probably degenerative in character, but they 
might easily be taken for evidences of plurality of papille 
were their history not accurately traced. The connective 
tissue is condensed around the proper Aulage of m®, and 
shows a true rudimentary dermal papilla filling the basal 
depression of the Anlage. No such condensation of papillary 
differentiation is present in relation to the pseudo-papilliform 
modifications of the proximal part of the lamina referred to 
above (fig. 69). 
Lower Jaw.—In the series at our disposal the region in 
front of i; was not available. The anterior region of 7; itself 
was also injured. Abundant traces of a fairly bulky residual 
lamina undergoing disintegration were, however, discernible, 
and these are continued into the region of 7,. 
The deciduous first incisor di; is still in evidence as a small 
and strongly calcified toothlet. ‘The second incisor now ex- 
tends forwards some distance in front of tz. The base of i; 
