With the effects of acculturation to be seen in all parts of the world, we may have to be reminded how recently its importance has been recognized. The twentieth century has brought us face to face with change, but the fact about culture which was most obvious in the last century was its stability. Some cultures had existed with little change over many centuries, and others had been spread through colonization to new parts of the world where they persisted despite considerable geographical differences. There was a tendency to take cultural stability for granted, though it was recognized that changes could result from migrations and conquests. The Tylorian theory of cultural evolution, developed only toward the end of the century, held that societies progressed from one stage to another as the result of internal change, but the manner in which these changes came about was almost mystical and inevitable. Other scholars seriously maintained that primitive peoples lived in “cultural straight jackets” which prevented change and, indeed, even individual variation in behaviour. It was widely believed that human behaviour was biologically determined, and that certain people were musical or amusical, or rhythmical and incapable of harmony, by virtue of their race. Learning as a means of cultural change had little place in these theories, and in the light of what we know today the important mechanism of cultural borrowing was completely underrated. It is sometimes hard to realize that the fact that folktales can and do diffuse from one place to another, without the agency of migration, had to be proved within the last hundred years