CAIUS JULIUS, a celebrated Roman grammarian, was a native of Spain, or, according to others, of Alexandria, in Egypt. He seems to have been at one time a slave, and to have been manumitted by Augustus, who made him keeper of the Palatine library. His master was the famous Alexander, surnamed Polyhistor, whom he is said to have imitated closely in his writings. Suetonius mentions that in his old age he fell into poverty, and was supported chiefly by the generosity of a rich consul named Licinius, who, with the poet Ovid, had been his most intimate friend in early life. The dates of his birth and death are alike unknown. Hyginus is frequently mentioned by Pliny and Aulus Gellius, and always with respect. Not one of his works has come down to us, and even of the titles only the following are known:—De Urbibus Italiciis; De Proprietatibus Deorum; De Virgilio Liber; De Familia Trojana; De Agricultura. Another Hyginus, who has been quite unwarrantably identified with this one, has transmitted to us two works, entitled respectively, Fabularum Liber, and Poeticon Astronomicon, libri iv. The first of these is a collection of legends from the old mythology, some of which are presented under new forms; the title of the second sufficiently explains its purport. Both of these works are written in a style so impure as to savour of the iron age; but who their author was, or when he flourished, has been very much disputed. Some critics even declare that they are merely translated from the Greek. To this Hyginus also are attributed treatises De Castrametatione, and De Limitibus Constituentibus, which have been several times reprinted.