Besides the new treatment of old forms, there were three kinds of poetry, first developed or perfected at Alexandria, which have special interest for us from the great celebrity they gained when imported into Rome. They are the didactic poem, the erotic elegy, and the epigram. The maxim of Callimachus (characteristic as it is of his narrow mind) _mega biblion mega kakon_, "a great book is a great evil," [39] was the rule on which these poetasters generally acted. The didactic poem is an illegitimate cross between science and poetry. In the creative days of Greece it had no place. Hesiod, Parmenides, and Empedocles were, indeed, cited as examples. But in their days poetry was the only vehicle of literary effort, and he who wished to issue accurate information was driven to embody it in verse. In the time of the Ptolemies things were altogether different. It was consistent neither with the exactness of science nor with the grace of the Muses to treat astronomy or geography as subjects for poetry. Still, the best masters of this style undoubtedly attained great renown, and have found brilliant imitators, not only in Roman, but in modern times. ARATUS (280 B.C.), known as the model of Cicero's, and in a later age of Domitian's [40] youthful essays in verse, was born at Soli in Cilicia about three hundred years before Christ. He was not a scientific man, [41] but popularised in hexameter verse the astronomical works of Eudoxus, of which he formed two poems, the _Phaenomena_ and the _Diosemia_, or Prognostics. These were extravagantly praised, and so far took the place of their original that commentaries were written on them by learned men, [42] while the works of Eudoxus were in danger of being forgotten. NICANDER (230 B.C.?), still less ambitious, wrote a poem on remedies for vegetable and mineral poisons (_alexipharmaka_), and for the bites of beasts (_thaeriaka_), and another on the habits of birds (_ornithogonia_). These attracted the imitation of Macer in the Augustan age. But the most celebrated poets were CALLIMACHUS (260 B.C.) and PHILETAS [43] (280 B.C.), who formed the models of Propertius. To them we owe the Erotic Elegy, whether personal or mythological, and all the pedantic ornament of fictitious passion which such writings generally display. More will be said about them when we come to the elegiac poets. Callimachus, however, seems to have carried his art, such as it was, to perfection. He is generally considered the prince of elegists, and his extant fragments show great nicety and finish of expression. The sacrilegious theft of the locks of Berenice's hair from the temple where she had offered them, was a subject too well suited to a courtier's muse to escape treatment. Its celebrity is due to the translation made by Catullus, and the appropriation of the idea by Pope in his _Rape of the Lock_. The short epigram was also much in vogue at Alexandria, and neat examples abound in the _Anthology_.