Camper's theory being refuted, _Blumenbach_ proposed another system. He called his invention _norma verticalis_, the vertical method. According to him,[124] the comparison of the breadth of the head, particularly of the vertex, points out the principal and most strongly marked differences in the general configuration of the cranium. He adds that the whole cranium is susceptible of so many varieties in its form, the parts which contribute more or less to determine the national character displaying such different proportions and directions, that it is impossible to subject all these diversities to the measurement of any lines and angles. In comparing and arranging skulls according to the varieties in their shape, it is preferable to survey them in that method which presents at one view the greatest number of characteristic peculiarities. "The best way of obtaining this end is to place a series of skulls, with the cheek-bones on the same horizontal line, resting on the lower jaws, and then, viewing them from behind, and fixing the eye on the vertex of each, to mark all the varieties in the shape of parts that contribute most to the national character, whether they consist in the direction of the maxillary and malar bones, in the breadth or narrowness of the oval figure presented by the vertex, or in the flattened or vaulted form of the frontal bone." The results which Blumenbach deduced from this method, were a division of mankind into five grand categories, each of which was again subdivided into a variety of families and types.