DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES, 585 
Fig. 4. Third section behind Fig. 3, showing di merging posteriorly in 
common dental lamina. 
Fig. 5. Third section behind Fig. 4, through Anlage of 73. 
All x 210 diameters. 
Fic. 6.—S. §. Cutting the anterior portions of the upper and lower dental 
lamine transversely, not far from the mesial plane. a. Alinasal cartilage. 
ch. Choanal passage. cm. Meckel’s cartilage. J.O. Organ of Jacobson. 
J. c. Cartilaginous capsule of Jacobson’s organ. ma. Maxillary palate. x. e. 
Epithelium of nasal cavity. pmz. Premaxilla. rf. Olfactory bulb. 8. d. 
Stenson’s duct. ¢. Tongue. x 25. 
Fic. 7.—U. J., C. §. Canine Anlage. x 210. 
Fig. 8.—U. J., C. S. Milk premolar (dp3). x 210. 
Fic. 9.—U. J., C. S. Milk premolar (dp?) in another embryo from same 
pouch, with commencing liberation of the residual dental lamina. x 130. 
Fic. 10.—S. §. dp® and molar segment of dental lamina (d/.). x 50. 
Fie. 11.—U. J., C. S. Anlage of m+ with commencing papilla-formation 
(mp.m+). xX 180. 
Fie. 12.—L. J., C. S. Anlage of diz. x 230. 
Fie. 13.—Z. J., C. 8. Canine Anlage. x 210. 
Fig. 14.—8S. S. dpz and molar dental lamina (d/.). x 50. 
Fie. 15.—Z. J., C. 8. First molar Anlage. x 180. 
Stace ITI.—P. obesula. 
Fic. 16.—U. J., H. S. Anterior end of dental lamina, showing the labial 
portion of the Anlage of 2+ as a lobe projecting at right angles from the 
main dental lamina (d/.), and the continuation backwards of the latter (d/’.) 
towards the region of 22. x 140. 
Fie. 17.—U. J., C. S. Second incisor mass, showing the labial portion of 
the Anlage of 22 projecting from the swollen lamina, and the representative 
of di2. x 180. 
Fic. 18.—U. J., H. S. Second and third incisor masses (II and III), with 
rudiments of di® and di3. The level of the section is indicated by the dotted 
linesa ....6in Figs.17 and 19. x 180. 
Fic. 19.—U. J., C. 8. Third incisor swelling, showing the narrow ‘ neck” 
attaching the mass to the oral epithelium and the remains of the enamel-organ 
of a3. x 180. 
Fic. 20.—U. J., C. S. Canine mass, showing the as yet undifferentiated 
Anlage of the permanent canine, with the cup-shaped enamel-organ of the 
milk canine (da), c.dl. The morphologically free edge of dental lamina. 
c. The probable equivalent of the labial lobe of the incisor masses. x 210. 
