EXPLANATION OF THE PLATES. 191 



FIG. II. Ivory and cementum. 1, Amorphous substance ; 

 canaliculi of the ivory, with their lateral anastomotic branches ; 

 3, dilatations in the course of the canaliculi ; 4, confluence of 

 several canaliculi ; 5, inter-globular spaces ; 6, cementum with 

 very large bone-corpuscles. Some of these latter communicate 

 with the cavities of the inter-globular spaces. 



FIG. III. Transverse section of the crown of a large 

 molar tooth. 1, Ivory, and terminations of its canaliculi ; some 

 of these canaliculi enlarge in diameter (2) and penetrate the 

 substance of the enamel ; 3, enamel, consisting of wavy and 

 parallel prisms ; they are seen in groups slightly diverging from 

 each other ; 4, lines of separation between the prisms. 



FIG. IV. Transverse section of enamel. 1, Prisms seen 

 in transverse section ; prisms divided a little obliquely. The 

 white lines are the intervals between the prisms. 



PLATE IX. 



MUSCLE. 



FIG. I. Muscular coat of the stomach treated by acetic 

 acid. 1, Finely granulated muscular fibre, with very pale out- 

 lines, often indistinctly visible ; 2, nuclei ; 3, lines of separation 

 between the muscular fibres ; 4, elastic fibres. 



FIG. II. Same coat in transverse section, and hardened by 

 moderate boiling. 1, Muscular fibres; 2, nuclei; 3, line of 

 separation between the fibres; 4, outline of a fasciculus of mus- 

 cular fibres. 



FIG. III. Dartos treated by acetic acid. 1, Very pale finely 

 granulated substance, corresponding to the muscular fibres ; 2, 

 elongated nuclei. 



FIG. IV. Embryonic fibres of striped muscle. 1, Two 

 varicose fibres formed by the union of embryonic cells; 2, 

 nuclei of these cells ; 3, two other fibres, a little longer and less 

 varicose ; 4, division of the contents of the cells into granules 

 and transverse striae ; 5, fibres showing the commencement of 



