competition has come to a focus. The population is exceedingly mixed. I have seen men of the purest Italian type speaking the German tongue; and at Botzen blond Teutons who made use of good Italian. Despite this circumstance of racial intermixture, there are within the Tyrol at the same time a number of areas of isolation which possess very marked individuality. We thus have the sharpest contrasts between mixed and pure populations. The Oetztal Alps, in the very center of the country, are as inaccessible as any part of Europe. So rugged is this latter district that the dialects differ from valley to valley, and the customs and social institutions as well.
Turning now to the anthropological map of this region, based upon a measurement of over twelve thousand skulls, it will be found that in nearly every case the broad heads become numerous in direct proportion to the increase in altitude. In other words, the broad open valleys leading out toward the great river systems of Europe are relatively dolichocephalic; while the side branches in the Oetztal Alps, isolated from foreign influences, show a marked preponderance of round-headedness. Thus in the Stanzerthal and the valley of the Schnals, indicated upon our map by the solid black tint, are two of the broadest-headed spots in the world. Over seventy per cent of all the heads measured from these two districts had indices above 85. These both lie, it will be observed, well off the main line of travel, either by the Inn Valley or over the Brenner. At their outlets they contain many heads of medium breadth, but these become less frequent as we penetrate the highlands. Like them are nearly all the side valleys in this part of the Alps. So closely, indeed, does this physical trait follow the topography that Ranke of Munich, as we have already said, has endeavored to connect the broad-headedness and altitude as cause and effect. For us the true explanation of this phenomenon is entirely racial. It is a product of genuine social selection. The two great branches of narrow-headedness, the blond Teuton at the north and the Mediterranean at the south with dark eyes and hair, have invaded the Alps all the way from France to the Balkan states. At the time of their coming a broad-headed population, as it would appear, occupied the whole mountain chain. The result is that to-day its main peculiarity has become attenuated exactly in proportion to the degree to which it has been exposed to racial intermixture with the newcomers.
Here is an example, then, of purely human stratification. The Alpine type has been overlaid by the newcomers, or else has been gradually driven up and back into the areas of isolation. Those who remained along the great routes of travel have been swamped in a flood of foreign intermixture. The only exceptions to the
