During prehistoric times the basin of the Vistula seems to have been inhabited by a dolichocephalic race, different from the brachycephalic Poles of the present day; but from the dawn of history Slays (Poles), intermingled to some extent with Lithuanians, have to be found on the plains of the Vistula and the Warta.
Castren considers them as a mixture of Ugrians with Mongolians, and Zograf as brachycephalic Mongolians.
Measurements of their skulls show them mesocephalic (index about 78), or intermediate between the dolichocephalic and brachycephalic types of mankind.
Two different races - a brachycephalic and a dolichocephaliccan be distinguished among the remains of the earlier Stone period (Lacustrine period) as having inhabited the plains of E.
The head is mesati-cephalic, verging on brachycephalic in the case of many of the Dokpa; the hair is black and somewhat wavy; the eyes are usually of a clear brown, in some cases even hazel; the cheek-bones are high, but not so high as with the Mongols; the nose is thick, sometimes depressed at the root, in other cases prominent, even aquiline, though the nostrils are broad.