We do not know what influences alter the shape of the skull, just as we do not know why people of British descent in the Darling region of Australia (“Cornstalks”) grow exceptionally tall, or why in New England their jaw-bones seem to become slighter and their teeth in consequence rather crowded. Even in Neolithic times dolichocephalic and brachycephalic skulls are found in the same group of remains and often buried together, and that is true of most peoples to-day. Some peoples, such as the mountain people of central Europe, have more brachycephalic individuals per cent. than others; some, as the Scandinavians, are more prevalently dolichocephalic. In Neolithic Britain and in Scandinavia the earliest barrows (= tomb mounds) are long grave-shaped barrows and the late ones round, and the skulls found in the former are usually dolichocephalic and in the latter most frequently brachycephalic. This points perhaps to a succession of races in western Europe in the Neolithic Period (see Chapter XLV), but it may also point to changes of diet, habit, or climate. [Illustration: Caucasian Types] But it is this study of skull shapes which has led many ethnologists to divide the Caucasian race, not, as it was divided by Huxley, into two, the northern _blonds_ and the Mediterranean and North African _dark whites_ or brunets, but into three. They split his blonds into two classes. They distinguish a northern European type, blond and dolichocephalic, the Nordic; a Mediterranean or Iberian race, Huxley’s dark whites, which is dark-haired and dolichocephalic, and between these two they descry this third race, their brachycephalic race, the Alpine race. The opposite school would treat the alleged Alpine race simply as a number of local brachycephalic varieties of Nordic or Iberian peoples. The Iberian peoples were the Neolithic people of the long barrows, and seem at first to have pervaded most of Europe and western Asia. [Illustration: Map of EUROPE, Western ASIA & Northern AFRICA in the Forest (Pluvial) Period (about 15,000 or 12,000 years ago) Showing probable range of the main races before the dawn of history. Mountain barriers are indicated thus [symbol] Sea barriers [symbol]] § 4