As to the American Indians, see Ethnological Report for 1880-81, p. 83, “From their close relations with wild animals Indians’ stories of transformations into beasts and beasts into men are numerous and interesting.... In times of peace, during the long winter evenings, some famous storyteller told of those days in the past when men and animals could transform themselves at will and hold converse with one another.”
Jacob Grimm, Teutonic Mythology, Bell & Sons, 1883, II. 668 says no metamorphosis occurs more frequently in Germanic antiquities than that of men into werewolves. Thus Fenrisûlfr, a son of Loki, makes his appearance in wolf’s shape among the gods.
Encyc. Brit. XV. 89 fol., under the heading Lycanthropy, states:—A belief firmly rooted among all savages is that men are in certain circumstances transformed temporarily or permanently into wolves and other inferior animals. In Europe the transformation into a wolf is by far more prominent and frequent (amongst Greeks, Russians, English, Germans, French, Scandinavians). Belief in metamorphosis into the animal most prominent in any locality itself acquires a special prominence. Thus the were-_wolf_ prevails in Europe, also in England, Wales, Ireland; and in S. France, the Netherlands, Germany, Lithuania, Bulgaria, Servia, Bohemia, Poland, Russia, he can hardly be pronounced extinct now (see note 12). In Denmark, Sweden, Norway and Iceland the _bear_ competes with the wolf for pre-eminence. In Persia the _bear_ is supreme; in Japan the _fox_; in India the _serpent_ vies with the _tiger_ (contrary to Mogk in Paul’s Grd., III. 272, who says:—“Nur Griechen, Römer, Kelten, Germanen, Slaven unter den indogermanischen Völkern kennen den Werwolf, den Indern und Iraniern ist er unbekannt.” Compare notes 6 and 9, Hertz, p. 133); in Abyssinia and Borneo the _hyena_ with the _lion_; in E. Africa the _lion_ with the _alligator_; in W. Africa the _leopard_ is perhaps most frequently the form assumed by man; among the Abipones the _tiger_, among the Arawaks the _jaguar_, etc.
In Brockhaus’ Konversations-Lexikon, for the Middle Ages the werewolf belief is ascribed to all Slavic, Keltic, Germanic and Romanic peoples; found to-day especially in Volhynia and White Russia.