DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES. 483 
mental relationships are totally distinct in the two cases. The 
appearance is explained by the kink in the lamina which has 
been described. 
In fig. 86 the dental lamina is seen continued back as a 
well-marked band from the hinder end of 7; through the 
canine region to the first premolar Anlage. The intermediate 
part of this elongated portion of the dental lamina really con- 
sists of the thinned-out ‘neck ” portion of the dental lamina, 
where that constitutes the canine Anlage. Its topographical 
relation to the vestigial milk canine d; is well shown. 
Behind the canine region the dental lamina is again reduced 
in size, until it is continued, as may be seen in the horizontal 
section figured (fig. 86), into the Anlage of py. Here it 
attains considerable bulk, and, unlike the corresponding 
Anlage in the upper jaw, it shows slight but distinct indenta- 
tion at its base, and the usual indication of the earliest com- 
mencement of a dermal papilla, in the form of a deeply stained 
cellular aggregation opposite the depression in the enamel- 
germ, and slightly projecting into it. 
Beyond pz the dental lamina becomes attenuated before it 
once more enlarges to constitute the Anlage of pz. This 
closely resembles pz, but is even more distinctly though still 
only slightly cupped (fig. 88). As ps is traced backwards the 
labial lobe, which forms the outer boundary of the shallower 
depression of the enamel-organ, disappears, but the main body 
of the dental lamina continues backwards, uniformly plump 
and well developed, for a very considerable distance; nor, 
indeed, does it lose its character, but merely undergoes further 
vertical elongation at its continuation into the residual dental 
lamina, which now exists in a well-developed condition by the 
side of the highly developed enamel-organ of dpz. Here it is 
longer, and, though a little less thick, it is still markedly 
swollen in its marginal portion, so that upon cross-sec- 
tion it appears like a large bud-like lobe (fig. 39, rdl.), 
and this is surrounded by a capsule of condensed connective 
tissue. 
The development of dpz so closely resembles that of the 
VOL. 39, PART 4+,—NEW SER. Lt 
