302 ON THE STRUCTURE AND DEVELOPMENT OE THE TEETH OP OPHIDIA. 
2. Tooth-germ which has an enamel-organ and dentine- organ. 
3, 4, 5, 6, 7. Older tooth-capsules. 
Fig. 3. Four tooth-germs from a transverse section of the lower jaw of a common snake, 
showing their relations with the oral epithelium, and their enclosure in a 
species of common capsule (lettering same as in other figures), xlOO. 
Fig. 4. Early tooth-germ, in which the double layer of cells originally constituting the 
enamel-organ can be seen. Common snake. X 150. 
Fig. 5. Longitudinal section of a tooth-capsule of a viper. The enamel cells are dimi- 
nished in size, and the base of the pulp has already its odontoblast layer, so 
that the tooth had evidently attained its full length, x 50. 
Fig. 6. Portion of tooth-germ seen in transverse section, embracing the odontoblast 
layer of the dentine-pulp (o), a thin layer, of dentine (d), enamel cells (/), and 
outside these a slight fibrous capsule, Xl50. 
Fig. 7. Tooth in process of attachment to the bone. The roughened surface of the 
jaw ( m ) is well seen, while the tooth is as yet attached to it only by the tissue 
represented at g, in which calcification is actively going on. The appear- 
ances observed at g do not materially differ from those seen at the edge of 
a rapidly growing membrane -bone. Common snake. 
Fig. 8. Transverse section of lower jaw of a common snake, with tooth cemented on 
by the “bone of attachment” ( h ). From a section mounted dry in Canada 
balsam. 
All the figures, with the exception of No. 8, are taken from sections hardened and 
decalcified in chromic acid, and stained with logwood or carmine. 
