=The Centaurs=, who probably symbolise mountain torrents or other forces of nature, appear (mostly on early vases) in combat with Herakles, either in troops or in single combat, as in the stories of Nessos, Dexamenos, and Eurytion[1470]; or, again, in the scenes so often celebrated in the sculptured friezes and metopes of Greek temples, where they contend with Theseus and Peirithoös,[1471] or with the Thessalian Lapiths.[1472] Among the latter a common episode is the death of Kaineus, whom the Centaurs buried in the earth, showering rocks upon him.[1473] In a more peaceful aspect appear the aged Centaurs, Pholos and Cheiron, especially in the stories of Herakles and Achilles,[1474] both of whom are brought to the latter for their youthful education.[1475] As the friend of Peleus Cheiron often assists at his capture of Thetis.[1476] Centaurs, especially Pholos, are sometimes represented returning from the chase,[1477] or as single decorative figures[1478]; in one case they fight with cocks.[1479] Nike in one or two instances is drawn in her chariot by male or female Centaurs[1480]; and, finally, representations of youthful Centaurs are found, though usually they are middle-aged.[1481] =The Gorgons= appear almost exclusively in connection with the Perseus legend,[1482] but are besides frequently found as decorative figures, especially on B.F. vases,[1483] in the running attitude characteristic of archaic art, in one case between two Sphinxes.[1484] Besides these, the head or mask of the Gorgon Medusa, familiar at all periods as a decorative motive of Greek art—first with an ugly and grotesque face, afterwards refined and beautiful—is often found by itself on Greek vases, especially as an interior central ornament of B.F. kylikes.[1485] =Harpies=, conventionally associated through the medium of the Roman poets[1486] with the human-headed bird-form which really denotes the Siren, are found invariably on vases in the form of winged women.[1487] They are, as has been elsewhere noted (p. 81), associated with the Boreades[1488] as symbolical of evil and good influences of winds, and probably should be regarded as personifications of the _southern_ breezes (the malevolent influence of which is seen in the sirocco). Traditionally they were supposed to guard the Garden of the Hesperides in Africa, whence the hot baleful winds come. The story of Phineus is probably to be explained on these lines.[1489] A Harpy appears at the recovery of Zeus’ golden dog from Pandareos.[1490]