_Anthropology_ is the science which studies man as a species; _Ethnology_, that which studies the various nations which make up the species. To both of these the science of Linguistics is more and more perceived to be a powerful, an indispensable auxiliary. Through it we get nearer to the real man, his inner self, than by any other avenue of approach, and it needs no argument to show that nothing more closely binds men into a social unit than a common language. Without it, indeed, there can be no true national unity. The affinities of speech, properly analyzed and valued, are our most trustworthy guides in tracing the relationship and descent of nations. If this is true in general, it is particularly so in the ethnology of America. Language is almost our only clue to discover the kinship of those countless scattered hordes who roamed the forests of this broad continent. Their traditions are vague or lost, written records they had none, their customs and arts are misleading, their religions misunderstood, their languages alone remain to testify to a oneness of blood often seemingly repudiated by an internecine hostility. I am well aware of the limits which a wise caution assigns to the employment of linguistics in ethnology, and I am only too familiar with the many foolish, unscientific attempts to employ it with reference to the American race. But in spite of all this, I repeat that it is the surest and almost our only means to trace the ancient connection and migrations of nations in America. Through its aid alone we have reached a positive knowledge that most of the area of South America, including the whole of the West Indies, was occupied by three great families of nations, not one of which had formed any important settlement on the northern continent. By similar evidence we know that the tribe which greeted Penn, when he landed on the site of this city where I now speak, was a member of one vast family,--the great Algonkin stock,--whose various clans extended from the palmetto swamps of Carolina to the snow-clad hills of Labrador, and from the easternmost cape of Newfoundland to the peaks of the Rocky Mountains, over 20° of latitude and 60° of longitude. We also know that the general trend of migration in the northern continent has been from north to south, and that this is true not only of the more savage tribes, as the Algonkins, Iroquois, and Athapascas, but also of those who, in the favored southern lands, approached a form of civilization, the Aztecs, the Mayas, and the Quiche. These and many minor ethnologic facts have already been obtained by the study of American languages.