. Quain's elements of anatomy . nt or points where calcification is about to commence. The dentine is produced more immediately by the elongated cells (odontoblasts)already described as forming the superficial stratum of the pulp (fig. 484, <?).These cells send out from their free extremities filamentous processes, as describedby Lent, and the .matrix or intertubular substance of the dentine, which is pro-bably shed out by the odontoblasts, becomes formed simultaneously between andaround these processes and is thus as it were moulded upon them, so as to formthe tubules in which the cell-pro
. Quain's elements of anatomy . nt or points where calcification is about to commence. The dentine is produced more immediately by the elongated cells (odontoblasts)already described as forming the superficial stratum of the pulp (fig. 484, <?).These cells send out from their free extremities filamentous processes, as describedby Lent, and the .matrix or intertubular substance of the dentine, which is pro-bably shed out by the odontoblasts, becomes formed simultaneously between andaround these processes and is thus as it were moulded upon them, so as to formthe tubules in which the cell-processes are now enclosed. The same cell maycontinue to spin out a filament until the tubule is completed in its whole length,and in many cases a cell sends out two or more processes, coalescing into oneas the cell recedes, the branched tubules being thus produced. The coUogenous basis of the dentinal matrix is at first uncalcified (fig. 484, V),but the material of calcification soon begins to be deposited in nodules or globules,. FORMATION OF THE DENTINE AND ENAMEL. 559 •wMch. ran together into a uniform hard substance (a). In parts where this co-alescence partially fails the uncalci&ed matter between the globules shrinks upwhen the tooth has become dry, so as to leave the interglobular spaces previouslydescribed (p. 552). The globular mode of deposition is indicated also by the innersurface of the growing dentine, which is nodulated (Czermak) ; and, indeed,separate nodules may be seen in the soft tissue of the growing matrix (seefig. iSi, I). Fig. 485.
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