Most of our readers must have heard of the wonderful discoveries of Cuvier respecting the extinct animals of a former world, and of the sagacity with which that profound anatomist disclosed the history of races, of whose existence the only evidence we possess depends upon the preservation of a few bones or fragments of skeletons. The same subject, which in the hands of genius has afforded such brilliant discoveries, has also afforded wide scope for credulity, and even imposture. The bones of the larger races of extinct animals were formerly believed alike by the learned and the vulgar to be those of giants. Even as late as the seventeenth century, learned anatomists believed that the bones of the extinct elephant belonged to a gigantic race of men. In the year 1577, some bones of the elephant were disinterred near the town of Lucerne, in Switzerland; the magistrates sent them to a professor of anatomy, who decided that they belonged to the skeleton of a giant, and the citizens were so delighted with the discovery that they adopted a giant as the supporter of the arms of their town, an honour which he still retains. In the same century, some bones of the elephant found in Dauphiny were exhibited in different parts of Europe as the remains of the general of the Cimbri who invaded Rome, and who was defeated by the consul Marius some time before the commencement of the Christian era. In this case, however, the mistake was not allowed to pass unnoticed, and the surgeons and physicians of Paris entered into a lengthened discussion respecting the nature of the bones; and the works written on this subject, if collected, would form a small library. The most extraordinary instance of mystification and credulity upon record is to be found in the history of a book on Petrifactions, published by a German professor at the commencement of the last century. We quote the following notice of this very rare book from a French publication:-- It is related in the life of Father Kircher, one of the most eccentric of men, that some youths, desirous of amusing themselves at his expense, practised the following mystification upon him. They engraved a number of fantastic figures upon a stone, which they afterwards buried in a place where a house was about to be built. The stone was found by the workmen while digging the foundation, and of course found its way to the learned Father, who was quite delighted with the treasure; and after much labour and research, he gave such a translation of the inscription as might have been expected from the whimsical disposition of the man. Kircher had been a professor at Wurzburg where this anecdote became well known, and led to another mystification of a much more serious nature, as it was pushed so far as to occasion the publication of a folio volume.