But the very idiom of the Norse was calculated to foster this superstition. The Icelanders had curious expressions which are sufficiently likely to have produced misconceptions. Snorri not only relates that Odin changed himself into another form, but he adds that by his spells he turned his enemies into boars. In precisely the same manner does a hag, Ljot, in the Vatnsdæla Saga, say that she could have turned Thorsteinn and Jökull into boars to run about with the wild beasts (c. xxvi.); and the expression _verða at gjalti_, or at _gjöltum_, to become a boar, is frequently met with in the Sagas. “Thereupon came Thorarinn and his men upon them, and Nagli led the way; but when he saw weapons drawn he was frightened, and ran away up the mountain, and became a boar. . . . And Thorarinn and his men took to run, so as to help Nagli, lest he should tumble off the cliffs into the sea” (Eyrbyggja Saga, c. xviii.) A similar expression occurs in the Gisla Saga Surssonar, p. 50. In the Hrolfs Saga Kraka, we meet with a troll in boar’s shape, to whom divine honours are paid; and in the Kjalnessinga Saga, c. xv., men are likened to boars—“Then it began to fare with them as it fares with boars when they fight each other, for in the same manner dropped their foam.” The true signification of _verða at gjalti_ is to be in such a state of fear as to lose the senses; but it is sufficiently peculiar to have given rise to superstitious stories. I have dwelt at some length on the Northern myths relative to were-wolves and animal transformations, because I have considered the investigation of these all-important towards the elucidation of the truth which lies at the bottom of mediæval superstition, and which is nowhere so obtainable as through the Norse literature. As may be seen from the passages quoted above at length, and from an examination of those merely referred to, the result arrived at is pretty conclusive, and may be summed up in very few words. The whole superstructure of fable and romance relative to transformation into wild beasts, reposes simply on this basis of truth—that among the Scandinavian nations there existed a form of madness or possession, under the influence of which men acted as though they were changed into wild and savage brutes, howling, foaming at the mouth, ravening for blood and slaughter, ready to commit any act of atrocity, and as irresponsible for their actions as the wolves and bears, in whose skins they often equipped themselves.