Marbodus, Bishop of Rennes in the twelfth century, was the author of the lapidary which was best known during the Middle Ages. This book, called "De Gemmis," was written in Latin verse, and gives the strange superstitions about the virtues and efficacies of sixty stones. Many of these stones are now unknown to us. There was so much interest in this lapidary that it was frequently translated into French, both in verse form and in prose, and was popular in England as well as in France. The traditions about stones developed two sorts of treatise: one in which the purely pagan beliefs are represented, as they were handed down by Aristotle, Pliny, Marbodus, and others; and a second in which the pagan superstitions are inwrought with Christian teachings and associated with Scriptural passages. In translating Marbodus, a Christian clerk would add and alter material in such a way as to impress religious symbolisms upon his readers, through the popular interest in all the lore of stones. Information regarding the lapidaries, as well as editions of various French and other lapidaries, will be found in the following books: PANNIER, L. Les Lapidaires français du moyen-âge des XII^e, XIII^e, et XIV^e siècles. Paris, 1882. MEYER, P. Les Plus Anciens Lapidaires français. _Romania_ (Jan., Avril, Oct.). Paris, 1909. KING, C. W. Antique Gems. Contains a translation of the work of Marbodus. London, 1860. STREETER, E. W. Precious Stones and Gems, their History, Sources, and Characteristics. Illustrated in color. London, 1898. WRIGHT, T. Popular Treatises on Science written during the Middle Ages. London, 1841. The accounts of diamond, sapphire, amethyst, geratite, chelidonius, coral, heliotrope, pearl, and pantheros are translated from a French prose version of the Latin of Marbodus. The French translation was made, perhaps, in England during the twelfth century. The text will be found in Meyer, pp. 271-285. The French prose lapidary has been chosen rather than that in verse form, because it has fewer tags and circumlocutions, and can be more faithfully rendered into English. The diamond, or adamant, was a favorite stone. "The Travels of Sir John Mandeville," pp. 105-108, The Macmillan Company, New York, 1905, has an interesting account of this. The pearl has been the subject of much discussion. The present translation omits several lines in the French version which do not appear in Marbodus and which seem to be due to confusion with another stone. Consult Kunz and Stevenson's "The Book of the Pearl," The Century Company, New York, 1908, and pp. 599-610 of Schofield's article "Symbolism, Allegory, and Autobiography in The Pearl." _Publications of the Modern Language Association_, Vol. XVII.