differentiation of the populations of the plains from those of the mountains which we have noted in other parts of Europe. Nor is a reason for the general absence of the phenomenon hard to find. If it be, indeed, an economic and social phenomenon, dependent upon differences in the economic possibilities of any
given areas, there is little reason for its appearance elsewhere in Italy; for the Apennines do not form regions of economic unattractiveness, as their geology is favorable to agriculture, and their soil and climate are kind. In many places they are even more favorable habitats than the plains, by reason of a more plentiful rainfall. The absence of anthropological contrasts coincident with a similar absence of economic differences is, in fact, a point in favor of our hypothesis.
Are there any vestiges in the population of northern Italy of
