in the Parthenon. Many of the surviving sculptures of Athena show this serpent. Herodotus records that a serpent lived in a crevice on the north side of the summit of the Athenian Acropolis and that the Athenians left a honey cake for it each month as an offering. On the eve of the Second Persian invasion of Greece in 480 BC, the serpent did not eat the honey cake and the Athenians interpreted it as a sign that Athena herself had abandoned them. Another version of the myth of the Athenian maidens is told in Metamorphoses by the Roman poet Ovid (43 BC17 AD); in this late variant Hermes falls in love with Herse. Herse, Aglaulus, and Pandrosus go to the temple to offer sacrifices to Athena. Hermes demands help from Aglaulus to seduce Herse. Aglaulus demands money in exchange. Hermes gives her the money the sisters have already offered to Athena. As punishment for Aglaulus's greed, Athena asks the goddess Envy to make Aglaulus jealous of Herse. When Hermes arrives to seduce Herse, Aglaulus stands in his way instead of helping him as she had agreed. He turns her to stone. Athena gave her favour to an Attic girl named Myrsine, a chaste girl who outdid all her fellow athletes in both the palaestra and the race. Out of envy, the other athletes murdered her, but Athena took pity in her and transformed her dead body into a myrtle, a plant thereafter as favoured by her as the olive was. An almost exact story was said about another girl, Elaea, who transformed into an olive, Athena's sacred tree. Patron of heroes According to Pseudo-Apollodorus's Bibliotheca, Athena advised Argos, the builder of the Argo, the ship on which the hero Jason and his band of Argonauts sailed, and aided in the ship's construction. Pseudo-Apollodorus also records that Athena guided the hero Perseus in his quest to behead Medusa. She and Hermes, the god of travelers, appeared to Perseus after he set off on his quest and gifted him with tools he would need to kill the Gorgon. Athena gave Perseus a polished bronze shield to view Medusa's reflection rather than looking at her directly and thereby avoid being turned to stone. Hermes gave him an adamantine scythe to cut off Medusa's head. When Perseus swung his blade to behead Medusa, Athena guided it, allowing his scythe to cut it clean