If, for instance, he had had before him the disconnected fragments of an eocene tillodont he would undoubtedly have referred a molar tooth to one of his pachyderms, an incisor tooth to a rodent, and a claw bone to a carnivore.

The tooth of a Hesperornis would have given him no possible hint of the rest of the skeleton, nor its swimming feet the slightest clue to the ostrich-like sternum or skull.

And yet the earnest belief in his own methods led Cuvier to some of his most important discoveries." Let us now examine from Cuvier's own words in his _Discours_, not relying on the statements of his expositors or followers, just what he taught notwithstanding the clear utterances of his older colleague, Lamarck, whose views he set aside and either ignored or ridiculed.[100] ~ ~ ~ ~ ~ He at the outset affirms that nature has, like mankind, also had her intestine wars, and that "the surface of the globe has been much convulsed by successive revolutions and various catastrophes." As first proof of the revolutions on the surface of the earth he instances fossil shells, which in the lowest and most level parts of the earth are "almost everywhere in such a perfect state of preservation that even the smallest of them retain their most delicate parts, their sharpest ridges, and their finest and tenderest processes." "We are therefore forcibly led to believe not only that the sea has at one period or another covered all our plains, but that it must have remained there for a long time and in a state of tranquillity, which circumstance was necessary for the formation of deposits so extensive, so thick, in part so solid, and filled with the exuviae of aquatic animals." But the traces of revolutions become still more marked when we ascend a little higher and approach nearer to the foot of the great mountain chains.

Hence the strata are variously inclined, and at times vertical, contain shells differing specifically from those of beds on the plains below, and are covered by horizontal later beds.

Thus the sea, previous to the formation of the horizontal strata, had formed others, which by some means have been broken, lifted up, and overturned in a thousand ways.