Small lakes are sources of small rivers, by which they are emptied. But great Titicaca forms no stream at all. Its outlet has no outlet of its own. The rush of nauseous water is poured into a shallow lake-twin not far away--Poopo, through whose mysterious whirlpools the water drops back again in subterranean escapes. This tumultuous torrent, the Desaguadero, was spanned in former days by a bridge of reeds. Recent measurements show that the level of these two lakes is constantly lowering, and eventually they will disappear. They were once the source of the greatest river in the world, but some day there will be only a salty deposit in the hollows they now fill. _Titi_, the cat, _kaka_, the rock, Lake Titicaca was named for a little island within it, around which cluster legends of the origins of things. It was the most revered shrine in the empire of the Incas. Neither the wide fields of Chita, where the flocks of the Sun gamboled, nor the valley of Yucay could equal this enchanted isle of Titicaca. Before the arrival of man, the island was inhabited by a tiger, carrying on its head a magnificent ruby, whose light illuminated the whole lake as the afterglow the snow-covered peaks above. The Hawaiians have an expression for the shifting of colors in a rainbow. The Indians on Lake Titicaca have special words for the glow of fading sunlight on the mountain summits and the purple of the glaciers in their hollows. The Sun had preserved himself from the flood by hiding in the depths of Lake Titicaca. This was his island, out of whose sacred rock, after the deluge, he soared like a big flame into the sky. His footsteps are still to be seen perpetuated in iron ore. The original Incas were let down by the Sun, their father, on to the small island and commanded to go forth to teach the savage inhabitants. But the worship given this spot by the Incas was only absorbed in that of former times. This “Island of the Wild Cat” is a field of aboriginal myth and tradition. The sacred cliff where the Sun had risen was covered by the Incas with sheets of gold and silver, “so that, in rising, he might see the whole rock ablaze, a signal to worship.” “Sixteen hundred attendants manufactured _chicha_ to throw at it, and pilgrims from the entire empire brought offerings of silver and gold.” Garcilasso says that “after all the vessels and ornaments of the temple were supplied, there was enough gold and silver left to raise and complete another temple without other material whatsoever.” All the treasure was thrown into Lake Titicaca to save it from the Spaniards. Ten of them were drowned in 1541, while hunting for it. Titicaca guards its secrets well.