It was not until Hellenistic times that the following systematic set of functions became associated with them, and even then some variation persisted both in their names and in their attributes:

According to Pausanias, who wrote in the later second century AD, there were originally three Muses, worshipped on Mount Helicon in Boeotia: Aoide (song or tune), Melete (practice or occasion), and Mneme (memory). Together, these three form the complete picture of the preconditions of poetic art in cult practice. In Delphi too three Muses were worshiped, but with other names: Nete, Mese, and Hypate, which are assigned as the names of the three chords of the ancient musical instrument, the lyre.Alternatively, later they were called Cephisso, Apollonis, and Borysthenis - names which characterize them as daughters of Apollo.A later tradition recognized a set of four Muses: Thelxinoë, Aoide, Archē, and Melete, said to be daughters of Zeus and Plusia or of Ouranos. One of the people frequently associated with the Muses was Pierus. By some he was called the father (by a Pimpleian nymph, called Antiope by Cicero) of a total of seven Muses, called Neilṓ (Νειλώ), Tritṓnē (Τριτώνη), Asōpṓ (Ἀσωπώ), Heptápora (Ἑπτάπορα), Achelōís, Tipoplṓ (Τιποπλώ), and Rhodía (Ῥοδία). Mythology
According to Hesiods Theogony (seventh century BC), they were daughters of Zeus, king of the gods, and Mnemosyne, Titan goddess of memory.
A common complication of the surgery is hemorrhage and the loss of blood. There is also the possibility of the hemangioma reoccurring after its removal. Additionally, the risk of a stroke or death is also possible.Treatments for cerebral cavernous hemangiomas include radiosurgery or microsurgery. The treatment approach depends on the site, size and symptoms present, as well as the history of hemorrhage from the lesion. Microsurgery is generally preferred if the cerebral cavernous hemangioma is superficial in the central nervous system, or the risk of damage to surrounding tissue from irradiation is too high. Additionally, a large hemorrhage with deterioration of the patient or intractable symptoms (such as seizures or coma) are further indications for microsurgical intervention. Gamma-knife radiation is the favored mechanism of radiosurgery. It provides a precise radiation dose to the cerebral cavernous hemangioma while relatively sparing the surrounding tissue. These treatment approaches for cavernous hemangiomas in other regions of the body have limited research. Prognosis
A few studies have worked on providing details related to the outlook of disease progression. Two studies show that each year 0.5% of people who have never had bleeding from their brain cavernoma, but had symptoms of seizures, were affected by bleeding. In contrast, patients who have had bleeding from their brain cavernoma in the past had a higher risk of being affected by subsequent bleeding. The statistics for this are very broad, ranging from 4–23% a year.