population of the British Isles to-day is so homogeneous. The average cephalic index of 78 occurs nowhere else so uniformly distributed in Europe, nor does it anywhere else descend to so low a level, save at the two extremes of the continent in Scandinavia and Spain. For purposes of comparison we have reproduced two maps of these regions herewith. Of Norway we know more in detail than of Sweden, thanks to the indefatigable Dr. Arbo; but the one country is typical of the other. These maps make it clear beyond a shadow of doubt that in these two outlying members of Europe we have to do with relatively homogeneous populations in this respect. Other facts in our possession prove that this uniformity of head form is the concomitant and index of two relatively pure, albeit widely different, ethnic types—Mediterranean in Spain, Teutonic in Norway. Purity of descent in each case—that is to say, freedom from ethnic intermixture—is the direct and inevitable outcome of peninsular isolation. It is now proper to ask—and this is the crucial question, to whose elucidation all of our argument thus far has been contributory—whether we may make the same assumption of racial purity concerning the British populations.
We have a case of insularity even more pronounced than in Spain or Norway; we have cephalic uniformity. The interest of our problem intensifies at this juncture. If relatively pure, have we to do with the type of the Teuton, or of the Iberian race? We