Caius Julius, an ancient Latin writer, who flourished in the time of Augustus. Suetonius, in his work De Illustribus Grammaticis, says that he was by birth a Spaniard; but some think that he was a native of Alexandria in Egypt. He was originally a slave of Julius Caesar, who brought him to Rome; but having distinguished himself by his literary acquirements, he was emancipated by Augustus, and placed at the head of the library which that sovereign had founded in the temple of the Palatine Apollo. Whilst in this situation, he became intimate with Ovid the poet; and Caius Licinius, a man of consular rank, has informed us that he died very poor, having been supported by the bounty of his friends; but some think that Caius Licinius is a mistake for Caius Asinius, who wrote a history of the civil war, and served as consul with Cneius Domitius Calvinus, in the year of the city 723. It is doubtful whether the works which have been preserved under his name are really the productions of the freedman of Augustus. These are Fabularum Liber, a collection of two hundred and seventy-seven fables, principally derived from Greek sources, and which are of great value in mythological inquiries; and Poeticon Astronomicum, an astronomical and mathematical work in prose. He is also supposed to have written on the subject of agriculture, and to have composed a book of Genealogies, of which mention is made in the Poeticon Astronomicum. Of this last work, the first book treats of the world and the doctrine of the sphere, and the second of the signs in the zodiac; the third contains a history and description of the constellations, and the fourth treats of the several things relating to the planets. But whilst Hyginus describes the constellations in the heavens, and enumerates the stars belonging to each, he takes occasion to explain the fables of the poets from which these constellations were supposed to have originally derived their names, and it is probably owing to this circumstance that the work has been denominated Poeticon Astronomicum. It has however come down to us in a very imperfect state; and all that part of it which treated of the month, the year, and the reasons for intercalating the months, has been entirely lost. To the Poeticon Astronomicum is usually appended a book of fables, containing a compendium of the heathen mythology; but this is also imperfect, and is moreover suspected to be spurious. The Liber Fabularum and the Poeticon Astronomicum have been published together at Basle, 1555, and at Hamburg, 1674; and separately at Paris, 1578, and at Leyden, 1670. The best editions are those which appeared with the commentary of Muncker, in a collection entitled Mythographi Latini, Amsterdam, 1681, reprinted with new notes by Van Staveren, Leyden, 1763. There are other works under the name of Hyginus, but they all belong to a later age: De Limitibus constitutis, published in a collection entitled Rei Agrarie Auctores, cura Gessii, Amsterdam, 1674; a Fragment on the proper mode of pitching a camp, published first by Scriverius, along with Vegetius, Leyden, 1607, and reprinted with a learned commentary by Scheleus, Amsterdam, 1661, and also by Graevius in his Thesaurus. Angelo Maio, the learned librarian of the Vatican, has added three new works on mythology to those which we already possessed, and one of these is under the name of Hyginus, but evidently by a writer of the fifth century. Other manuscripts of the same works have since been discovered at Göttingen, Gothe, and Paris; and Dr Bode has published a new edition, with a careful collation of these manuscripts, Scriptores Rerum Mythicarum Latini tres Romae nuper reperti, Celle, 1834. For the life of Hyginus, freedman of Augustus, consult Scheffer, De Hyginis Script. Fabul. atate atque stylo; and Muncker, De auctore, stylo, et estate Mythologiae quae C. Hygini nomen proferit.