The analogy to the Greek and the English drama need not be forced. Without any straining of comparisons, it may be argued that the relation of the _Atlamál_ and _Atlakviða_ is like the relation of Euripides to Aeschylus, and not so much like the variations of ballad tradition, in this respect, that the _Atlamál_ is a careful, deliberate, and somewhat conceited attempt to do better in a new way what has been done before by an older poet. The idylls of the heroines, Brynhild, Gudrun, Oddrun, are not random and unskilled variations; they are considerate and studied poems, expressing new conceptions and imaginations. It is true that this poetry is still, in many respects, in the condition of popular poetry and popular traditional stories. The difference of plot in some versions of the same subject appears to be due to the ordinary causes that produce the variants of popular tales,--defective memory, accidental loss of one point in the story, and change of emphasis in another. To causes such as these, to the common impersonal accidents of tradition, may perhaps be referred one of the strangest of all the alterations in the bearing of a story--the variation of plot in the tradition of the Niblungs. In the "Elder Edda" the death of the Niblungs is laid to the charge of Attila; their sister Gudrun does her best to save them; when she fails in this, she takes vengeance for them on her husband. In the German tradition, as in the version known to Saxo in the _Nibelungenlied_, in the Danish ballad of _Grimild's Revenge_ (which is borrowed from the German), the lines are laid quite differently. There it is their sister who brings about the death of the kings; it is the wife of Sigfred, of Sigfred whom they have killed, that exacts vengeance from her brothers Gunther and Hagene. Attila is here put aside. Gudrun's slaughter of her children is unrecorded; there is no motive for it when all her anger is turned against her brothers. This shifting of the centre of a story is not easy to explain. But, whatever the explanation may be, it seems probable that it lies somewhere within the range of popular tradition, that the change is due to some of the common causes of the transformation of stories, and not to a definite and calculated poetical modification. The tragical complications are so many in the story of the Niblungs that there could not fail to be variations in the traditional interpretation of motives, even without the assistance of the poets and their new readings of character. In some of the literary documents there may be found two kinds of variation from an original form of story,--variation due to those popular and indefinite causes, the variation of failing memory, on the one hand; and on the other, variation due to the ambition or conceit of an author with ideas of his own.