NERVES TO ODONTOBLASTS, AND ON THE GROWTH OF DENTINE. 333 



Waldeyer, W., "Human and Comparative Histology," Strieker's Handbook, Syden. Soc, vol. i. p. 463, 1870. 



Gegenbaur, " Elements of Comparative Anatomy" 1878, p. 551. 



Tomes, C. S., " Cuticula Dentis," Quart. Jour. Micr. Sci, 1872; Manual of Dental Anat., 1876; " On the 



Develop, of Teeth," Quart. Jour. Micr. Sci, 1876 ; " On Vascular Dentine," Phil. Trans., 1878, p. 25. 

 Frey, Histology, 4th edit., 1879, p. 261. 

 Rutherford, Prof. W., Text Book of Physiology, pt. i., 1880. 

 Turner, Prof. Sir W., " Introduction to Human Anatomy" 1877. 

 Klein and Noble Smith, Atlas of Histology, 1880. 

 Balfour, F. M., Comparative Embryology, vol. ii. p. 638, 1881. 

 Landois and Stirling's Physiology, 3rd edit., 1888. 

 M'Kendrick, Text Book of Physiology, 1889. 

 Sharpey, Quain's Anatomy, 9th edit., 1882, vol. ii. p. 552. 

 Brunn, Dr A. v., " Ueber die Ausdehnung des Schmelzorganes und seine Bedeutung fur die Zahnhildung," 



Archiv fur Mikrosk. Anatomie, 1887, p. 367. 



DESCRIPTION OF THE FIGURES IN THE ACCOMPANYING PLATE. 



Fig. 1. Teased portion of pulp of ox tooth. Shows long projecting axis cylinder processes ; on one a piece of 



the white sheath is seen separated from its nerve fibre. 

 Fig. 2. Shows medullated and non-medullated nerve fibres. 



Fig. 3. Scraping from inner surface of dentine. Shows odontoblasts with their long central processes. 

 Fig. 4. Surface of pulp. Distal processes of odontoblasts seen projecting from surface. Odontoblasts are 



seen pulled away from the surface though still attached to it by their central process. In one both 



distal and central processes are seen springing from each extremity. 

 Fig. 5. Portion of surface of pulp teased in potassium anhydrochromate solution. Shows very long central 



process belonging to each odontoblast and entering substance of pulp. The odontoblast has 



fallen off in many cases, and leaves the central process projecting like a fine hair or nerve fibre. 

 Fig. 6. Pallisade-like arrangement of distal processes of odontoblasts seen on surface of pulp. 

 Fig. 7. Apparent direct continuation of root process of odontoblast with axis cylinder of nerve. 

 Fig. 8. Section through upper part of incisor tooth of rabbit. Shows obliterated upper end of pulp cavity. 

 Fig. 9. Shows the same more highly magnified. Osseous lamella?, small round cells, and capillaries seen. 

 Fig. 10. To illustrate various stages in growth of a flask-shaped tooth, as the canine tooth of the cat. 

 Fig. 11. Diagrammatic representation of the manner of growth of a persistently growing tooth, as a rabbit's 



incisor. Shows gradual widening out of the basal formative ring, with constant deposition of new 



dentine. 

 Fig. 12. Diagrammatic representation of the manner of growth of a flask-shaped tooth ; showing gradual 



enlargement of formative ring to form the " crown-cone," and then its more gradual contraction to 



produce the " fang-cone "; shows also the diminution in size of the pulp cavity through deposit of 



new dentine. 

 Fig. 13. To show fang-formation — the basal formative ring subdividing into two or three smaller rings 



according to the number of fangs to be produced. 

 Fig. 14. Incisor and premolar teeth of young rabbit fed for two weeks on madder. The shading on the dentine 



represents the amount of that tissue formed during the period on which the animal had madder 



added to its food. 

 Fig. 15. Same teeth in young rabbit fed for an equal period on madder, then for two weeks on ordinary food. 

 Fig. 16. Same teeth in young rabbit fed for three weeks on ordinary food, after having been fed on madder for 



two weeks. 



VOL. XXXVI. PART II. (NO. 14). 3 F 



