Note 67 — Chapter II · —Classes Of Geographic Influences

Enough has been said to show that the geographer can formulate no broad generalization as to the relation of pigmentation and climate from the occurrence of the darkest skins in the Tropics; because this fact is weakened by the appearance also of lighter tints in the hottest districts, and of darker ones in arctic and temperate regions. The geographer must investigate the questions when and where deeper shades develop in the skins of fair races; what is the significance of dark skins in the cold zones and of fair ones in hot zones. His answer must be based largely on the conclusions of physiologists and physicists, and only when these have reached a satisfactory solution of each detail of the problem can the geographer summarize the influence of environment upon pigmentation. The rule can therefore safely be laid down that in all investigation of geographic influences upon the permanent physical characteristics of races, the geographic distribution of these should be left out of consideration till the last, since it so easily misleads.67 Moreover, owing to the ceaseless movements of mankind, these effects do not remain confined to the region that produced them, but pass on with the wandering throng in whom they have once developed, and in whom they endure or vanish according as they prove beneficial or deleterious in the new habitat.