But before entering upon this inquiry it may be well to see what legend or tradition tells us with regard to the Celtic portion of the population, with which we have now mainly to do. Such legends or traditions are either intended as a means of conveying some early facts in the history of the race in a popular form, or of clothing some truths in a symbolic dress, or they are merely the picturesque imaginations of their early sennachies or native historians. Those which relate to the Celtic population of Scotland are derived from two different sources. They are either Welsh or Irish, that is, they are the legends of either the Cymric or the Gaelic race, and in estimating their relative value it is necessary to take their probable origin and character into account. Some of them are what may be termed ethnic legends. They are designed to perpetuate the popular conception of the origin and early settlements of the race, but they are the creation of a period when there had been some progress in the culture of the people, and when they possessed a rude literature derived in the main from the spread of Christianity and the establishment of Christian institutions among them. Their authors felt the necessity of connecting the early history of the country with the events of Biblical or Classical history, and it assumed the shape of a fictitious narrative which belongs to the mythic period of their annals. Others again may be called linguistic legends, and were rude attempts to account for peoples nominally distinct, and from pride of race regarding each other as independent races, possessing the same language and using a cognate form of speech. Others were what may be truly called historical legends, and handed down in a more or less modified shape events which we have reason to think actually took place; while others again were purely artificial, and were simply the rude and fantastic creations of the popular mind, which felt the necessity of filling up the dark period of the annals of their race with imaginary events calculated to gratify their national feeling and their natural love of the marvellous. [Sidenote: Ethnic legends.]