It is easy to understand why historical art holds no high place among the lower—that is, the hunting and fishing—tribes. Even if, as is the case in Australia, every unusual occurrence is represented in art with a view of keeping up its memory,[249] these accidental interruptions in a monotonous life cannot possibly contribute to the development of an historical interest—that is to say, a commemorative attention in the people. When, on the other hand, we meet, in barbaric and semi-barbaric tribes, with a flourishing traditional art, we can also, in most cases, point to some peculiar features in their life which have called for commemoration. In a general survey of traditional poetry one cannot but be struck by the great prevalence of legends about migrations.[250] As travels and incidents of travel were found to provide a favourite subject for the pantomimes and poems described in the preceding chapter, so these experiences have also exercised an important influence on the songs that have been preserved by oral tradition. And as we meet with numerous instances of improvised drama and poetry called forth by so eminently interesting an occurrence as the visit of some white people, so we can also trace the same theme in manifestations of historical art from dim and distorted narrations up to richly detailed descriptions like those of the Hawajian songs or of the Mangaian “Drama of Cook.”[251] The influence which these motives have exercised on the history of art is only in accordance with the universal laws of psychology. Tribal memory, no less than individual memory, is dependent for its development on some favourable external influences that stimulate the attention.