But sagas are not only perhaps the most ancient of tales, they are certainly the most persistent. By their attachment to places and to persons, a religious sanction is frequently given to them, a local and national pride is commonly felt in preserving them. Thus they are remembered when nursery tales are forgotten; they are more easily communicated to strangers; they find their way into literature and so are rendered imperishable.
Fairy Tales of both these classes are compounded of incidents which are the common property of many nations, and not a few whereof are known all over the habitable globe. In some instances the whole plot, a more or less intricate one, is found among races the most diverse in civilization and character. Where the plot is intricate, or contains elements of a kind unlikely to have originated independently, we may be justified in suspecting diffusion from one centre. Then it is that the history and circumstances of a nation become important factors in the inquiry; and upon the purity of blood and the isolation from neighbouring races may depend our decision as to the original or derivative character of such a tradition. Sometimes the passage of a story from one country to another can be proved by literary evidence. This is markedly the case with Apologues and Facetious Tales, two classes of traditions which do not come within the purview of the present work. But the story has then passed beyond the traditional stage, or else such proof could not be given. In tracing the history of a folk-tale which has entered into literature, the problem is to ascertain how far the literary variations we meet with may have been influenced by pre-existing traditional tales formed upon similar lines. In general, however, it may be safely said of Fairy Tales (with which we are more immediately concerned) that the argument in favour of their propagation from a single centre lacks support. The incidents of which they are composed are based upon ideas not peculiar to any one people, ideas familiar to savages
