DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES. 569 
Text-fig. 2 (aA) shows the common laminar Anlage attached 
to the oral epithelium (which exhibits on its oral surface a 
trace of the actual furrow). This section corresponds exactly 
Fic. 3, a—c.—Pig embryo of 20 mm. head-length. Three serial coronal 
sections, upper canine region. a. Just in front of © 3B. Through 
middle region of ¢. oc. Through posterior region of * x 45. 
in its relation to the molar lamina with that shown in fig. 83 
from the upper jaw, and shows only a very slight variation 
therefrom in form. The next three outlines (text-fig. 2, 
B, C, D,) are from sections taken at intervals of a few 
sections further forwards. Of these, p shows the definitive 
separation of the labio-alveolar Anlage from the proper dental 
lamina by an increase of the connective-tissue basis of the 
alveolus. 
