This story, the invention of a ninth or tenth century Christian scribe to account for the current knowledge of the many invasions of Ireland,[1222] must have been based on pagan myths of a similar kind, involving successive transformations and a final rebirth. Such a myth may have been told of Taliesin, recounting his transformations and his final rebirth, the former being replaced at a later time by the episode of the Transformation Combat, involving no great lapse of time. Such a series of successive shapes--of every beast, a dragon, a wolf, a stag, a salmon, a seal, a swan--were ascribed to Mongan and foretold by Manannan, and Mongan refers to some of them in his colloquy with S. Columba--"when I was a deer ... a salmon ... a seal ... a roving wolf ... a man."[1223] Perhaps the complete story was that of a fabulous hero in human form, who assumed different shapes, and was finally reborn. But the transformation of an old man, or an old animal, into new youthful and vigorous forms might be regarded as a kind of transmigration--an extension of the transformation idea, but involving no metempsychosis, no passing of the soul into another body by rebirth. Actual transmigration or rebirth occurs only at the end of the series, and, as in the case of Etain, Lug, etc., the pre-existent person is born of a woman after being swallowed by her. Possibly the transformation belief has reacted on the other, and obscured a belief in actual metempsychosis as a result of the soul of an ancestor passing into a woman and being reborn as her next child. Add to this that the soul is often thought of as a tiny animal, and we see how a _point d'appui_ for the more materialistic belief was afforded. The insect or worms of the rebirth stories may have been once forms of the soul. It is easy also to see how, a theory of conception by swallowing various objects being already in existence, it might be thought possible that eating a salmon--a transformed man--would cause his rebirth from the eater. The Celts may have had no consistent belief on this subject, the general idea of the future life being of a different kind. Or perhaps the various beliefs in transformation, transmigration, rebirth, and conception by unusual means, are too inextricably mingled to be separated. The nucleus of the tales seems to be the possibility of rebirth, and the belief that the soul was still clad in a bodily form after death and was itself a material thing. But otherwise some of them are not distinctively Celtic, and have been influenced by old _Märchen_ formulæ of successive changes adopted by or forced upon some person, who is finally reborn. This formulæ is already old in the fourteenth century B.C. Egyptian story of the _Two Brothers_.