The North American Indians have been the subject of numerous popular fallacies, some of which have gained world-wide currency. Here belongs a mass of pseudo-scientific and thoroughly unscientific literature embodying absurd and extravagant theories and speculations as to the origin of the aborigines and their "civilizations" which derive them (in most extraordinary ways sometimes), in recent or in remote antiquity, from all regions of the Old World--Egypt and Carthage, Phoenicia and Canaan, Asia Minor and the Caucasus, Assyria and Babylonia, Persia and India, Central Asia and Siberia, China and Tibet, Korea, Japan, the East Indies, Polynesia, Greece and ancient Celtic Europe and even medieval Ireland and Wales. Favourite theories of this sort have made the North American aborigines the descendants of refugees from sunken Atlantis, Tatar warriors, Malayo-Polynesian sea-farers, Hittite immigrants from Syria, the "Lost Ten Tribes of Israel," &c., or attributed their social, religious and political ideas and institutions to the advent of stray junks from Japan, Buddhist votaries from south-eastern Asia, missionaries from early Christian Europe, Norse vikings, Basque fishermen and the like. Particularly interesting are the theories of "Welsh (or white) Indians" and the "Lost Ten Tribes." The myth of the "Welsh Indians," reputed to be the descendants of a colony founded about A.D. 1170 by Prince Madoc (well known from Southey's poem), has been studied by James Mooney (_Amer. Anthrop._ iv., 1891, 393-394), who traces its development from statements in an article in _The Turkish Spy_, published in London about 1730. At first these "Welsh Indians," who are subsequently described as speaking Welsh, possessing Welsh Bibles, beads, crucifixes, &c., are placed near the Atlantic coast and identified with the Tuscaroras, an Iroquoian tribe, but by 1776 they had retreated inland to the banks of the Missouri above St Louis. A few years later they were far up the Red river, continuing, as time went on, to recede farther and farther westward, being identified successively with the Mandans, in whose language Catlin thought he detected a Welsh element, the Moqui, a Pueblos tribe of north-eastern Arizona, and the Modocs (here the name was believed to re-echo Madoc) of south-western Oregon, until at last they vanished over the waters of the Pacific Ocean. The theory that the American Indians were the "Lost Ten Tribes of Israel" has not yet entirely disappeared from ethnological literature. Many of the identities and resemblances in ideas, customs and institutions between the American Indians and the ancient Hebrews, half-knowledge or distorted views of which formed the basis of the theory, are discussed, and their real significance pointed out by Colonel Garrick Mallery in his valuable address on "Israelite and Indian: A Parallel in Planes of Culture" (_Proc. Amer. Assoc. Adv.