Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/192

 188 bone upon the nose, (Pl. 24, Fig. 14.) The concurrence of peculiarities so remarkable as the union of this nasal horn with a mode of dentition of which there is no example, except in the Iguanas, affords one of the many proofs of the universality of the laws of co-existence, which prevailed no less constantly throughout the extinct genera and-species of the fossil world, than they do among the living members of the animal kingdom.

As the teeth are the most characteristic and important parts of the animal, I shall endeavour to extract from them evidence of design, both in their construction and mode of renewal, and also in their adaptation to the office of consuming vegetables, in a manner peculiar to themselves. They are not lodged in distinct sockets, like the teeth of Crocodiles, but fixed, as in Lizards, along the internal face of the dental bone, to which they adhere by one side of the bony substance of their root. (Pl. 24, Fig. 13.)

The teeth of most herbivorous quadrupeds, (exclusively of the defensive tusks,) are divided into two classes of distinct office, viz. incisors and molars; the former destined to collect and sever vegetable substances from the ground, or from the parent plant; the latter to grind and masticate them on their away towards the stomach. The living Iguanas, which are in great part herbivorous, afford a striking exception to this economy: as their teeth are little fitted for grinding, they transmit their food very slightly comminuted into the stomach.

Our giant Iguanodon, also, had teeth resembling those of the Iguana, and of so herbivorous a character, that at first sight they were supposed by Cuvier to be the teeth of a Rhinoceros.

The examination of these teeth will lead us to the discovery