In America, from the Eskimos to the Orinoco banks, from the burning plains to the icy Strait of Magellan, mother tongues, quite different in terms of their roots, share the same physiognomy. We recognize striking analogies in grammatical structure, not only in the more learned languages like that of the Incas, the Aymara, the Guaranu, Cora and Mexican, but also in the more primitive ones. It is thanks to this structural analogy rather than words in common that the mission Indian learns another American language more easily than a metropolitan one. In the Orinoco jungle I have met the dullest Indians who speak two or three languages.