The archipelago of Tierra del Fuego, which consists of the large island of the same name, and numerous smaller islands, many of which are rocky, ice-bound and forbidding in aspect, constitutes the extreme southern territorial limits of the continent, and is separated from the mainland by the Strait of Magellan. The aborigines of this far southern territory are divided into three tribes,--the Onas, Yahgans and the Alacalupes. It is among these tribes, inhabiting a wild and forbidding country, undisturbed by the march of progress and civilization, that one may find the indigenous races living under the same conditions and maintaining the traditions and customs that prevailed before the coming of the white man to the western world. ONAS. The Onas are physically a fine race of people, the average height of the men being a little over six feet; the women are also tall and muscular. They have no system of tribal government, and are nomadic. Their only occupation is hunting the guanaco, a fur-coated herbivorous animal found in great numbers in the lower ranges of the Andes Mountains in the south. The meat of the guanaco constitutes the chief food supply of the Onas, and many of them subsist upon it entirely. The skins of the animals are made into a sort of manta, which constitutes the only costume worn by the men. They discard this costume when at war, or in pursuit of the guanaco. The women wear only a small piece of guanaco skin about their loins. The Onas live in families, one man usually possessing several women. There is little regard for marriage rites or usage, the more powerful and valiant of the men selecting such women from the tribe as they may desire, and are able to maintain against their rivals. Their only weapons are bows and arrows, slings and harpoons, the latter being pointed with barbed bone spikes. The number of Onas is now estimated at three thousand five hundred, but like the other tribes in Chile they are decreasing. YAHGANS. The coast of the Beagle Channel and all the archipelago south of Tierra del Fuego to Cape Horn is inhabited by the Yahgan Indians. They have no chiefs nor tribal laws and are perhaps the lowest grade of human beings, in point of intelligence, and in the manner and customs of living, existing on the American continent. They are dwarfed in stature, have very dark skins and are repulsive in appearance. A peculiar feature of the Yahgans is the extraordinary projection of their front teeth, which are used for opening the shells of oysters and mollusks. These bivalves and crustacea, their sole article of food, are eaten raw.