To the casual observer, at least, the Mongols do not present the same individual differences as their neighbours, the Chinese. In complexion they are nearly all alike, although the skin seems to get darker as the face becomes wrinkled with age, which might seem to favour the idea that the brownish skin of the Mongols is due as much to their habits as to their descent, or the effects of climate. But the causes which influence colour are very obscure. In Siberia, where Sclavonic races have been settled for nearly two centuries, living side by side with Mongol tribes, and exposed to the same climatic influences, these show no signs of variation from the complexion of their ancestors, as it is exhibited by their European representatives. Again, the Portuguese settlers in Macao, who degenerate very rapidly, become in two or three generations much darker in the skin than the native Chinese. It is not the smoky atmosphere of their tents that darkens the skin of the Mongols, for in that case, the women, who are more exposed to it, would be darker than the men, the reverse of which is the case. A comparison with the Japanese again would seem to show that exposure exercises at the most an insignificant effect in darkening the skin. The Japanese live much within doors, and are careful to protect themselves from the sun when they stir abroad by means of broad-brimmed hats and umbrellas. Great differences of complexion exist among them, whether regarded as individuals or classes; but it is safe to say they are on the whole quite as dark as the Mongols. The contrast between men and women is singularly marked, the women having fair clear complexions, often rosy. Yet the Japanese women are a good deal out of doors, and are fairer skinned than the Chinese women, who are only blanched by confinement to the house and exclusion from light and air. The Mongols, although deficient in muscular energy, and incapacitated for sustained activity, are nevertheless gifted with great powers of endurance. I have already noticed their capacity for enduring prolonged fasts, and their ability to go several days and nights without sleep, with equal impunity. The sudden and important changes to which their climate is subject, are also borne without any great suffering. From a hot summer, they are plunged, with but slight gradations, into an extremely rigorous winter, when the temperature falls very low, and is accompanied by keen cutting winds, that sweep over the steppes with merciless fury, and from which they have no better protection than their tents.