the hero's foes. Divinities sometimes hid in a magic mist, as the Tuatha Dée Danann did on arriving in Ireland; they could appear to such mortals as they pleased, remaining unseen by others. Gods were probably not regarded as spiritual beings. Like the dead in Celtic belief, they had resplendent corporeal forms and ate and drank; but their bodily form differed from men's in that it could become invisible and was not subject to the laws of gravitation. The gods travelled through the air or appeared above men's heads.
How, then, did they appear when visible.? Sometimes in the magnificence of divinity, yet still in anthropomorphic form. Sometimes they were of vast size, like the Morrígan or the Welsh Bran, while a goddess who sought the aid of Fionn was enormous compared even with the gigantic Féinn. Sometimes they appear merely as mortals and are not recognized as gods. Instances of this are found in the story of Cuchulainn's birth, where Lug is seen, as a mortal host in a mysterious house, and in that of Merlin's father; invisible to all but his mother, and later taking human shape. Sometimes a disguise was assumed. Oengus and Midir appeared to Rib and Eochaid in the shape of hospitallers, with a haltered pack-horse, and bade them begone. Gods also took the appearance of particular mortals, as when Midir appeared to Etain as her lover Ailill, or Manannan as Fiachna to the latter's wife, or as when Pwyll and Arawn exchanged forms.6
Animal forms were also assumed. Of these one favourite shape was that of birds. Morrigan appeared to Cúchulainn as a bird; so also do Devorgilla and her handmaid, the former being in love with the hero. Llew took the form of an eagle; Bude and his foster-brother that of birds when the former wished to visit his paramour, whose husband Nár slew them. Midir and Etain, Fand and Liban were seen as birds Hnked together. The gods, or síde, appear as deer in one story. Again, I the idea of divine shape-shifting, expressed, however, in the well-known folk-tale formula of the "Transformation Com-
