outsider. This is equally true in respect to customs and folklore; so that the Basque frontier can be detected all along the line from village to village. The present boundary is of such a form that it denotes a complete equality of the two rival tongues. It has remained immovable for many generations.
The clearness of this frontier in France is interestingly illustrated by a bit of detail on the accompanying map. It concerns that loop which is roughly indicated upon the larger map just east of Bayonne. Here at the village of La Bastide-Clairence for generations has been a little tongue of Bearnais-French, penetrating deeply into Basque territory. The name of this town indicates a fortress, and another "Bastide" occurs in the tongue farther north. Broca inclines to the view that here was a bit of territory in which the French patois was so strongly intrenched that it held its own against the advancing Basque. It may have been a reconquest, to be sure. For us, the sharpness of frontier is the only point of concern, in contrast with the one in Spain. It is an undoubted instance of linguistic invasion toward the north.
Another difficulty, no less insuperable than the fact that their language was on the move in a quiescent population, lay in the 
Detail—Basque-French Boundary. way of the old assumptions that the Basques were pure and undefiled descendants of some very ancient people. Study of the head form precipitates us at once into it. No sooner did physical anthropologists take up the matter of Basque origins than they ran up against a pair of bars. Study of the cephalic index yielded highly discordant results. Those who, like Broca and Virchow, measured heads or skulls of the Basques in Spain, discovered a dolichocephalic type, with an index ranging about 79 on the living head. Equally positive were those like Pruner Bey, who investigated the head form on the French slopes of the Pyrenees, that the Basque was broad-headed. The indexes obtained in this
