Evidence as to the date of their migration or the length of time they may have been settled in Argentina we have none, but there is a theory of considerable plausibility to the effect that there was a break in the continuity of the human race in South America. It has already been shown that the bones of huge extinct animals appear very frequently in Argentina; indeed, as Darwin remarks, "the whole area of the Pampas is one wide sepulchre for these extinct animals." Now, mingled with them have often been found human bones and the tools and weapons of man in his pleistocene stage. Near Buenos Aires,[16] for example, a discovery was made of bones of the mastodon, machairodus, and other extinct animals, and together with them were mingled human bones and tools in stone and bone. These facts help to strengthen the hypothesis that at a remote period of antiquity there occurred some gigantic natural cataclysm which swept away alike man and the vast animals with which he lived in these regions. Little as we know about the origin of South American man we can, of course, classify the races which are known to exist in South America or which existed when the Spaniards appeared.[17] The aborigines may be divided into three great races--the Ando-Peruvian, the Pampean, and the Brasilio-Guaranian. The Ando-Peruvian has three branches, known as the Peruvian proper, the Antisian, and the Araucanian. The Pampean likewise has three branches--the Pampean proper, the Chiquitean, the Moxean; while the Brasilio-Guaranian has no ramifications. The Peruvians, who do not concern us here, include, of course, the whole of the Inca race. The Antisians are so called because they lived in the mountains east of Cuzco, which the Incas called Antis (hence Andes), and they now inhabit the hot and moist forest-lands of Bolivia and Peru. They are, and always have been, savages, with clear olive complexions and slight, somewhat effeminate figures. The Tacana is their most important tribe. The Araucanians (who include the Fuegians) are more important for our purpose, and are a very hardy race, who fought for hundreds of years on equal terms with the Spaniards and were finally subdued rather by the subtle blight of civilisation than by arms. A Frenchman[18] who visited the River Plate in the middle of the eighteenth century describes them in the following terms: "The Indians who inhabit this part of America, north and south of the river de la Plata, are of that race called by the Spaniards Indios bravos. They are middle-sized, very ugly, and afflicted with the itch. They are of a deep tawny colour, which they blacken still more by continually rubbing themselves with grease. They have no other dress than a great cloak of roe-deer skins hanging down to their heels, in which they wrap themselves up. These skins are very well dressed; they turn the hairy side inwards and paint the outside with various colours. The distinguishing mark of their cacique is a band or strap of leather,