INFLUENCE OF PHYSICAL SURROUNDINGS.
Man is not only the most highly organized of all animals, but also the most cosmopolitan of all. So wonderfully adjusted is his structure that lie can live and thrive in a range of two hundred degrees of temperature.
Nothing like this can be said of any other vertebrate. He also resides with equal comfort in valleys far below the sea-level, as that of the Dead Sea, and on table-lands and mountain-sides fifteen to twenty thousand feet above the sea, as in Thibet and South America, where even an animal so tenacious of life as the cat perishes. The tribes of some regions are exclusively vegetarians, in others they eat nothing but animal food ; during the bitter winters of Patagonia they go almost naked, and under a tropical sun many are constantly clothed. There is little difference in man's vigor whether he is roaming over the arid plains of the Sahara, where rain never falls, or in the mountains of North-easteru India, where the animal rainfall is nearly three hundred inches.
Adaptability of the to man's extraordinary powers of accommodation these diverse conditions of existence exert a remarkably small influence either on his mental or bodily nature. The Eskimo amid his wild wastes of snow, and in spite of the depressing influence of the long polar night, is more cheerful, garrulous, inventive, and happy than many of the tribes of the most favored climes. The school of ethnol ogists who endeavored to explain man's physical differences, and to trace the course of his civilization, principally by means of climate and his other physical environments, has now fallen to the rear. It is recognized that man is stronger than his surroundings, and that their influence upon him is far from that of master (comp. p. 396).
Effects of Climate on Physical regard to which term is generally meant temperature and moisture—it cannot be said that it exerts any pronounced effect either on the bodily or mental powers after the system has become " acclimated." This process may take, indeed, several generations. It is well known that the children of European parents in India are feeble and short-lived ; but this is not owing to any inherent inability in the European race to support the climate of the country, inasmuch as a large portion of the natives are pure Aryans, descended from the same remote ancestors as the English themselves. The languor and love of idleness which we often associate with a tropical climate are contradicted by the colossal architectural works which we find in the tropics of both hemispheres, and by the exceedingly laborious lives of the inhabitants of many tropical regions.
The porters of Calcutta and Madras and the dyewood- and mahogany gatherers of Central America are generally men of exceptional vigor, with whom it is no unusual task to labor at their onerous employments twelve to fourteen hours a day with the thermometer at mo° F. in the shade.
On the Duration of Li does climate seem to exert any very positive impression on the duration of life or the power of reproduction in the human race. In the hottest portion of the globe, the region lying along the shores of the southern extremity of the Red Sea, the natives are generally long-lived and have numerous progeny. It has been asserted that the tribes of the extreme North are less fertile and are rather short-lived, but it appears from more careful observations that their marriages have an average fertility, though the infant mortality is excessive, either from carelessness or infanticide, and that want and exposure are the common causes of the death of the aged—all prevent able causes.
On the Height, Strength, and qualities of height, strength, and weight are also largely independent of climate and sur roundings. Within the limits of British Guiana we find the tall, sym metrical, and powerfully-built Carib and the weak and stunted Warrau, both natives of the spot for time out of mind. Many of the Polynesians, hemmed in on their small islands, are described as offering the finest examples of splendid physical form.
Effects of probably exerts a more direct influ ence on the physical structure than climate. The rarity of the atmo sphere requires a greater expansion of the breast to admit the proper amount of oxygen to the blood, and the unusual development of the thorax leads to corresponding changes elsewhere. A striking example of this is furnished by the tribes which for generations have lived on the high lands of Peru and Bolivia with a minimum elevation of ten thou sand feet. They are remarkable for their long bodies, broad shoulders, deep and high chest-walls, and disproportionately short legs. These characteristics are transmitted, and remain in their descendants even when for generations they have lived in the lower levels along the seacoast.