516 J. T. WILSON AND J. P. HILL. 
dp is now a narrow tooth much elongated vertically, which 
has cut the gum. Its residual lamina first becomes discernible 
opposite its anterior end. 
The Anlage of pz; is now more bulky than in preceding 
stages. It is placed opposite the hinder part of dpz, and 
though of larger size exhibits only a very slight depression 
answering to the cupping of the enamel-organ ; and here its 
papilla can hardly be said to exist as such, though the con- 
nective tissue is evidently tending towards its formation by 
local cellular accumulation opposite the depression. 
In the posterior molar region the dental lamina ends as a 
free laminar mass by the lingual side of mz, and in front of 
the middle of that tooth. The Anlage of mz does not seem to 
have made progress in the interval which separates this from 
the preceding stage. 
Stage X.—P. nasuta. 
Length from tip of snout to root of tail ; . 118 mm. 
Head length . : Se SON: 
This stage is distinctly eamtior naan on the whole than 
the preceding one, but the deciduous premolars are only just 
cutting the gum, while in Stage 1x they had already protruded 
somewhat. 
In the upper jaw no teeth have undergone eruption save dp3, 
but in the lower jaw the lower incisors have broken through in 
addition to the deciduous premolar. 
In the region of the canine there are still to be found abun- 
dant remains of the residual dental lamina in the shape of 
detached cell-masses, embedded in the fibrous connective tissue 
lingually from the well-developed canine. These disappear 
and reappear frequently in the serial sections, and, in various 
sections widely separated from one another, one of the detached 
cell-masses assumes a very definite pear-shaped form, and is 
surrounded by a distinct connective-tissue capsule (fig. 72). 
This pear-shaped mass is always the deepest mass present, and 
obviously corresponds to the fundus-portion of the residual 
lamina. Its appearance is highly suggestive of the “ knospen- 
