Man is less affected by climate in his bodily development than any other animal; his frame is at the same time so hardy and flexible, that he thrives and increases in every variety of temperature and situation, from the tropic to the pole; nevertheless, in extremes such as these, his complexion, size, and vigor usually undergo considerable modifications.[229] Among the Red Men of America, however, there is a remarkable similarity of countenance, form, manners, and habits, in every part of the continent. No other race can show people speaking different languages, inhabiting widely different climates, and subsisting on different food, who are so wonderfully alike.[231] There are, indeed, varieties of stature, strength, intellect, and self-respect to be found among them; but the savage of the frozen north, and the Indian of the tropics, have the same stamp of person, and the same instincts.[232] There is a language of signs common to all, conveying similar ideas, and providing a means of mutual intelligence to every Red Man from north to south. The North American Indians are generally of a fair height and proportion. Deformities or personal defects[233] are rare among them; and they are never seen to fall into corpulency. Their features, naturally pleasing and regular, are often distorted by absurd attempts to improve their beauty, or render their appearance more terrible. They have high cheek bones, sharp and rather aquiline noses, and good teeth. Their skin is generally described as red or copper-colored, approaching to the tint of cinnamon bark, a complexion peculiar to the inhabitants of the New World. The hair of the Americans, like that of their Mongolian ancestors, is coarse, black, thin, but strong, and growing to a great length. Many tribes of both these races remove it from every part of the head except the crown, where a small tuft is left, and cherished with care. It is a universal habit among the tribes of the New World to eradicate every symptom of beard: hence the early travelers were led to conclude that the smoothness of their faces resulted from a natural deficiency. One reason for the adoption of this strange custom was to enable them to paint themselves with greater ease. Among old men, who have become indifferent to their appearance, the beard is again seen to a small extent.[234]