Beside the Eddas, much information is to be derived from the various Sagas or northern histories. These Sagas, at times transmitting true historical events, at other times containing the wildest fictions of romance, preserve much valuable mythic lore, and the Ynglinga, Volsunga, Hervarar, and other Sagas, will furnish many important traits of northern mythology. It is not intended here to attempt sounding the depths of Eddaic mythology, a subject so obscure, and concerning which so many and various opinions occur in the works of those who have occupied themselves with it. Suffice it to observe that it goes back to the most remote ages, and that two essential parts of it are the Alfar (_Alfs_ or _Elves_) and the Duergar (_Dwarfs_), two classes of beings whose names continue to the present day in all the languages of the nations descended from the Gotho-German race. "Our heathen forefathers," says Thorlacius,[96] "believed, like the Pythagoreans, and the farther back in antiquity the more firmly, that the whole world was filled with spirits of various kinds, to whom they ascribed in general the same nature and properties as the Greeks did to their Dæmons. These were divided into the Celestial and the Terrestrial, from their places of abode. The former were, according to the ideas of those times, of a good and elevated nature, and of a friendly disposition toward men, whence they also received the name of White or Light Alfs or Spirits. The latter, on the contrary, who were classified after their abodes in air, sea, and earth, were not regarded in so favourable a light. It was believed that they, particularly the _land ones_, the δαιμονες επιχθονιοι of the Greeks, constantly and on all occasions sought to torment or injure mankind, and that they had their dwelling partly on the earth in great thick woods, whence came the name Skovtrolde[97] (_Wood Trolls_), or in other desert and lonely places, partly in and under the ground, or in rocks and hills; these last were called Bjerg-Trolde (_Hill Trolls_): to the first, on account of their different nature, was given the name of Dverge (_Dwarfs_), and Alve, whence the word Ellefolk, which is still in the Danish language. These Dæmons, particularly the underground ones, were called Svartálfar, that is Black Spirits, and inasmuch as they did mischief, Trolls." This very nearly coincides with what is to be found in the Edda, except that there would appear to be some foundation for a distinction between the Dwarfs and the Dark Alfs.[98] THE ALFAR. Ther ro meth Alfum. BRYNHILDAR QUIDA. Those are with the Alfs. In the prose Edda, Ganglar inquires what other cities beside that in which the Nornir dwelt were by the Urdar fount, under the Ash Yggdrasil.[99] Hár replies,