Yet conceptions pass from land to land and folk to folk, like an epidemic, and become assimilated by each new race that breathes or imbibes them, and as the Gaels have contributed to the thought of the Norsemen, so have the Vikings in turn impressed their ideas, especially their legends and beliefs, upon the imaginative race with whom they mingled, and by whom they ultimately became absorbed. When we remember that, in the opinion of the best authorities, even the very oldest of the Gaelic sagas could hardly have been written down before the seventh or eighth century, and that many of them are of much later date, we can well conceive how a Norse element might enter largely into them. It is well known that the Lochlanners or Norsemen figure largely in the Ossianic poems, and “it is quite evident,” says Dr. Hyde, “that most of them, at least in the modern form in which we now have them, are post-Norse productions.” In the Mythological, which is really the latest in point of writing, while the Fomorians who dwelt in Lochlann, vicious and troublesome invaders as they were, may in their origin be conceived as none other than the sea-powers personified—the rough chaotic tumult of the Atlantic Ocean, against which in the west of Ireland the various settlers had to contend, they might more literally represent the Viking rovers which later ages had to encounter, and by whom they were so often harassed and overcome. In such stories as The Children of Lir, and more particularly The Children of Tuireann, we have Gaelic examples of Norse beliefs and superstitions. Take, for instance, shape-changing, of which there are many illustrations in the Viking sagas. We are reminded at once of the unhappy fate of the children of Lir, when we read in the Hrolf Kraki, cc. 25, 26, that “King Hring of Uppdalir in Norway had a son Björn, and when his wife died, he married a woman from Tuinmôrk. She changed her stepson into a bear in this way. She struck him with a wolf-skin glove, and said that he should become a fierce and cruel lair-bear, and use no other food than the cattle of his father.” She went on to say, “Thou shalt kill it for thy food, so much of it that it will be unexampled, and never shalt thou get out of this spell, and this revenge shall harm thee.” Then it is told that the king’s cattle were killed in large numbers, as a big and fierce grey bear began to attack them. One evening the Bondi’s daughter (Björn’s sweetheart) happened to see this fierce bear, which came and fondled her much. She thought she recognised in the animal the eyes of her lover, and followed him to his den, where, strange to relate, she saw, not the bear, but a man. And Björn, for he was no other, told her he was a beast by day and a man by night.