But these exceptional effects are of small relative moment; the general principle, continually at work, in the main controls the result. In regard to the themes of stories especially, the many tongues and dialects of Western Europe offer scarcely more variation than will be often found to exist among the versions of the same tale which may be discovered in a single canton. The spirit of the language, already mentioned as constituting the element of nationality, taking possession of this common stock of knowledge, moulds its precise form and sentiment in accordance with its own character; it is in details, rather than in outlines, that racial differences are found to exist; this principle applies in a considerable degree in the field of folk-tales, even between cultures so opposite as those of Western Europe and Western Africa. In the case of superstitions, the diffusive process, though less rapid or effectual than in tales, is nevertheless continually active; in Europe, at least, a similar identity will probably be discovered. But in this category the problem of separating what is general, because human, from that which is common, because diffused, always a complicated task, will be found more difficult than in literary matter, and without the aid of extensive collection insoluble. It is possible to fall back on the consideration that, after all, such resolution matters not very much, since in any case the survival of the belief indicates its humanity, and for the purpose of the study of human nature borrowed superstitions may be cited as confidently as if original in the soil to which they have emigrated, and where they have indissolubly intertwined themselves with thought and habit. Again, it is to be considered that while differences of speech impede, but do not prevent integration, changes of condition may have an immediate effect in producing differentiation. Protestantism, by banishing complicated usages connected with sacred days, has caused English folk-lore to vary from Continental; so far this contrast seems a result of the alterations of the last three hundred years, rather than of more remote inconsistency. If these remarks are in any degree valid, it follows that from the presence or absence of any particular item of belief in this or that English-speaking district no conclusion is to be drawn; the deficiency must be supposed to proceed from absence of record, and seldom to depend on the structure of the population. To this general doctrine, as usual with such propositions, may be observed minor exceptions. Whatever doubts may be cast on the operation of the principle as applicable to England, there can be no doubt that it is valid in the United States and Canada.