COMPLEX AND COMPOUND TEETH. 



239 



and transverse to the long diameter of the tooth. When 

 the tooth is bisected vertically and lengthwise, the three 

 substances, c/, dentine, e, enamel, and c, cement, are seen 

 interblended, as in Fig. 58, in which p is the common 

 pulp-cavity, and t one of the roots of this complex tooth. 

 Such are some of the prominent features of a field of 



Fis. 58. 



LONGITUDINAL SECTION OF PART OF GRINDER OF ELEPHANT. 



observation which Comparative Anatomy opens out to 

 our view — such the varied nature, and such the gradation 

 of complexity of the dental tissues, which, up to December, 

 1839, continued, notwithstanding successive approxima- 

 tions to the truth, to be described, in systematic works, 

 as a "phaneros," or "a dead part or product, exhaled 

 from the surface of a formative bulb!"^ 



• See the Fasciculus of M. de Blainville's great work, " Osteographie 

 et Odontograpliie d'Animaux Vcrtebrcs," -which he submitted to the 



