About the middle of this century, two German travelers, Von Tschudi and Von Martius, gave close attention to the linguistic ethnology of the continent, Von Tschudi in Peru and Von Martius in Brazil. The former found the field so unoccupied that he did not hesitate to write in a work published less than ten years ago, “In fact, the knowledge of the languages of South America is to-day less than it was two hundred years ago.”[222] His own divisions of the linguistic regions (_Sprachgebiete_) of the continent is less satisfactory than we might expect. He describes three principal and seven minor districts, the former being, 1. The Pampo-Andean; 2. The inter-Andean; and 3. The Tupi-Guarani regions. The minor centers are, 1. The Arawak-Carib region; 2. That of Cundinamarca; 3. The Rio Meta; 4. The Rio Tolima; 5. The Rio Atrato; 6. The Rio Salado; 7. The Chaco; 8. That of the Moxos. These are so far from meeting the requirements of our linguistic possessions at present that scarcely one of them can be accepted. Von Tschudi was an able and critical scholar in his particular field, that of the Kechua tongue, but he had not made a wide study of South American languages. Von Martius was much more of a comparative linguist. His work on the ethnography and linguistics of South America[223] is a mine of general information, and indispensable to every student of the subject. Taking the numerous and confused dialects of Brazil, and the almost hopeless synonymy of its tribal names, he undertook a classification of them by establishing verbal and grammatical similarities. It is now generally recognized that he went too far in this direction. He maintained, for instance, that there is a demonstrable relationship between the Tupi, the Carib, and the Arawak stocks; later studies have not endorsed this, but have tended to show that they cannot be traced to any common mother-speech. What Martius called the “Guck” nations, which he brought into connection through the word of that sound used by them to designate the paternal uncle, are now considered to be without general relationship. The researches of Karl Von Den Steinen and Lucien Adam have overthrown this theory.