On the 3d of January 1454 the Pope writes again to Perotti thanking him for the third book; and in a letter to Torelli, dated 13th November 1453, Perotti says that he had finished his translation of Polybius in the preceding September. This translation was first printed in 1473. The Greek text was not printed till 1530, when an edition of the first five books in Greek, along with Perotti’s translation, was published at the Hague, _opera Vincentii Obsopaei_, dedicated to George, Marquess of Brandenburg. Perotti’s translation was again printed at Basle in 1549, accompanied by a Latin translation of the fragments of books 6 to 17 by Wolfgan Musculus, and reprinted at the Hague in 1598. The chief fragments of Polybius fall into two classes; (1) those made by some unknown epitomator, who Casaubon even supposed might be Marcus Brutus, who, according to Plutarch, was engaged in this work in his tent the night before the battle of Pharsalus. The printing of these began with two insignificant fragments on the battle between the Rhodians and Attalus against Philip, Paris, 1536; and another _de re navali_, Basle, 1537. These fragments have continually accumulated by fresh discoveries. (2) The other class of fragments are those made by the order of Constantinus Porphyrogenitus (911-959), among similar ones from other historians, which were to be digested under fifty-three heads or tituli; one of which (the 27th) has come down to us, discovered in the sixteenth century, containing the _selecta de legationibus_; and another (the 50th) _de virtute et vitio_. The printing of the first of these begins with the edition of Fulvius Ursinus, published at Antwerp in 1582. This was supplemented in 1634 (Paris) by an edition by Valesius of _excerpta ex collectaneis Constantini Augusti Porphyrogeneti_. The first edition of something like a complete text of Polybius, containing the five entire books, the _excerptae legationes_, and fragments of the other books, was that of Isaac Casaubon, Paris, 1609, fo. It was accompanied by a new and very brilliant Latin translation, and a preface which has been famous among such works. It contains also a Latin translation of Aeneas Tacticus. Altogether it is a splendid book. Some additional _annotationes_ of Casaubon’s were published after his death in 1617, Paris.[2] Other editions followed; that of Gronovius, Amsterdam, 1670: of Ernesti, Leipsic, 1764, containing Casaubon’s translation more or less emended, and additional fragments. But the next important step in the bibliography of Polybius was the publication of the great edition of Schweighaeuser, Leipsic, 1789-1795, in nine volumes, with a new Latin translation,—founded, however, to a great extent on Casaubon,—a new recension of the text, and still farther additions to the fragments; accompanied also by an excellent Lexicon and Onomasticon. This great work has been the foundation from which all modern commentaries on Polybius must spring. Considerable additions