(Ἴακχος), the solemn name of the mystic Bacchus at Athens and Eleusis. The Phrygian Bacchus was looked upon in the Eleusinian mysteries as a child, and as such he is described as the son of Demeter (Deo or Calligeneia) and Zeus, and as the brother of Cora, that is, the male Cora or Corus. (Aristoph. Frogs 338; Soph. Antig. 1121, &c.; Orph. Hymn. 51, 11.) His name was derived from the boisterous festive song which is likewise called Iacchus. (Aristoph. Frogs 321, 400; Hdt. 8.65; Arrian, Arr. Anab. 2.16.) From these statements (comp. Schol. ad Aristoph. Ran. 326), it is clear that the ancients distinguished Iacchus, the son of Zeus and Demeter, from the Theban Bacchus (Dionysus), the son of Zeus and Semele, nay, in some traditions Iacchus is called a son of Bacchus, but in others the two are confounded and identified. (Soph. Antig. 1115, &c., 1154; Strab. x. p.468; Verg. Ecl. 6.15; Ov. Met. 4.15.) He is also identified with the infernal Zagreus, the son of Zeus and Persephone. (Schol. ad Pind. Isthm. 7.3, ad Eurip. Orest. 952, ad Aristoph. Ran. 401, 479; Arrian, l.c.) At Athens a statue of Iacchus, bearing a torch in his hand, was seen by the side of those of Demeter and Cora. (Paus. 1.2.4, 37.3.) At the celebration ofthe great Eleusinian mysteries in honour of Demeter, Persephone, and Iacchus, the statue of the last divinity, carrying a torch and adorned with a myrtle wreath, was carried on the sixth day of the festival (the 20th of Boedromion) from the temple of Demeter across the Thriasian plain to Eleusis, accom panied by a numerous and riotous procession of the initiated, who sang the Iacchus, carried mystic baskets, and danced amid the sounds of cymbals and trumpets. (Schol. ad Pind. Isthm. 7.3; Plut. Themist. 15, Camill. 19; Hdt. 8.65; Athen. 5.213; Verg. G. 1.166.) In some traditions Iacchus is described as the companion of Baubo or Babo, at the time when she endeavoured to cheer the mourning Demeter by lascivious gestures; and it is perhaps in reference to this Iacchus that Suidas and Hesychius call Iacchus ἥρως τις.