In this curious pieces of animal mechanism, we find a varied adjustment of all parts and proportions of the tooth, to the exercise of peculiar functions; attended by compensations adapted to shifting conditions of the instrument, during different stages of its consumption. And we must estimate the works of nature by a different standard from that which we apply to the productions of human art, if we can view such examples of mechanical contrivance, united with so much economy, of expenditure, and with such anticipated adaptations to varying conditions in their application, without feeling a profound conviction that all this adjustment has resulted from design and high intelligence.
SECTION XI.
AMPHIBIOUS SAURIANS ALLIED TO CROCODILES.
The fossil reptiles of the Crocodilean family do not deviate sufficiently from living genera, to require any description of peculiar and discontinued contrivances, like those we have seen in the Ichthyosaurus, Plesiosaurus, and Pterodactyle; but their occurrence in a fossil state is of high importance, as it shows that whilst many forms of vertebrated animals have one after another been created, and become extinct; during the successive geological changes of the surface of our globe; there are others which have survived all these changes and revolutions, and still retain the leading features under which they first appeared upon our planet.
If we look to the state of the earth, and the character of its population, at the time when Crocodilean forms were first added to the number of its inhabitants, we find that the highest class of living beings were reptiles, and that the only other vertebrated animals which then existed were fishes; the carnivorous reptiles at this early period must therefore
