Fig. 62. A section from the outer part of the dentine. The 'tubes' very narrow.

PLATE X.

To illustrate the structure of dentine, nervous ganglia and a tissue composed of 'stellate cells.'

Fig. 63. A fragment of dentine near the pulp cavity with the prolongations of the masses of germinal matter in part of their course still retained in situ. The prolongation of the germinal matter into the solid matter which occupies the 'dentinal tube' is well seen.

Fig. 64. One of the oval masses of germinal matter on the surface of the pulp with a small portion of the structure prolonged from it. This is surrounded by the matrix about to receive the calcareous deposit, only the inner part of which is torn away with the structure figured in the drawing. A number of small spherical particles are seen in the substance of the matter of which the contents of the 'dentinal tube' are composed x 2800 diameters.

Fig. 65. One of the ganglion cells with nerve fibres connected with it from a nerve distributed to the pericardium of the ox. The large nucleus of the ganglion cell is seen, but in its substance, principally near the surface, a number of small oval nuclei resembling those in the nerves are also visible.

Fig. 66. A small portion of one of these 'ganglion cells' showing the continuity of the nerve fibre with the substance of the 'cell.'

Fig. 67. A portion of a ganglion on the side of a nerve showing ganglion cells and arrangement of the nerve fibres. Figs. 65 and 66 represent two of the 'cells' shown in this drawing more highly magnified.

Fig. 68. Tissue with stellate cells in immediate contact with the cementum of the fang of an incisor tooth. This is described under prep. 52, page 12. Towards the right of the