difficulty of the material to follow. Many have observed the parallels between the dramatic endings of each half of this book and the irresistible power of their respective themes of love and death. Book Four Book four, a tonal counterpart to book two, is divided approximately in half; the first half (1–280) is didactic and deals with the life and habits of bees, supposedly a model for human society. Bees resemble man in that their labour is devoted to a king and they give their lives for the sake of the community, but they lack the arts and love. In spite of their labour, the bees perish and the entire colony dies. The restoration of the bees is accomplished by bugonia, spontaneous rebirth from the carcass of an ox. This process is described twice in the second half (281–568) and frames the Aristaeus epyllion beginning at line 315. The tone of the book changes from didactic to epic and elegiac in this epyllion, which contains within it the story of Orpheus and Eurydice. Aristaeus, after losing his bees, descends to the home of his mother, the nymph Cyrene, where he is given instructions on how to restore his colonies. He must capture the seer, Proteus, and force him to reveal which divine spirit he angered and how to restore his bee colonies. After binding Proteus (who changes into many forms to no avail), Aristaeus is told by the seer that he angered the nymphs by causing the death of the nymph Eurydice, wife of Orpheus. Proteus describes the descent of Orpheus into the underworld to retrieve Eurydice, the backward look that caused her return to Tartarus, and at last Orpheus' death at the hands of the Ciconian women. Book four concludes with an eight-line sphragis or seal in which Virgil contrasts his life of poetry with that of Octavian the general. Sources Greek Virgil's model for composing a didactic poem in hexameters is the archaic Greek poet Hesiod, whose poem Works and Days shares with the Georgics the themes of man's relationship to the land and the importance of hard work. The Hellenistic poet Nicander's lost Georgics may also be an important influence. Virgil used other Greek writers as models and sources, some for technical information, including the Hellenistic poet Aratus for astronomy and meteorology, Nicander for information about snakes, the philosopher Aristotle for zoology, and Aristotle's student Theophrastus for