the Civil War. Professor Boas of Columbia University has been studying recent immigrants. He writes: "I think, therefore, that we are justified in the conclusion that the removal of the East European Hebrew to America is accompanied by a marked change in type, which does not affect the young child born abroad, but which makes itself felt among the children born in America, even in a short time after the arrival of the parents in this country. The change of type seems to be very rapid, but the changes continue to increase so that the descendants of immigrants born a long time after the arrival of the parents differ more from their parents than do those born a short time after the arrival of the parents in the United States." 20 These changes are in the shape of the head form, hitherto considered very fixed. The Hebrew becomes more long-headed, the Italian more roundheaded. Such striking conclusions need a verification, yet lacking, before being unqualifiedly accepted. The Snake Indians of the Rockies differed much in stature from the Blackfeet or Sioux of the plains. The environment by fixing occupation may in large measure determine physical characters. Darwin attributed the thin legs of the Indians of the Paraguay River to the constant canoe life. The man who lives in the saddle acquires a rolling gait when walking as does the sailor. The stooping shoulders of the farmer are likewise due to his trade. A very important and practical question which cannot be finally answered at the present time is whether the blond types of humans can survive in the tropics. In part this is a question of control of disease but it has other aspects. There is some reason to believe that the 20 BOAS, F. Changes in Bodily Form, p. 52. "Conse white races cannot permanently endure the constant heat and the effects of the actinic rays of the sun. quently we find that man is invariably covered with a pigment which acts as an armor to exclude the more harmful short rays, and moreover the amount of pigment is in direct proportion to the intensity of the light of the country to which his ancestors have proved their adjustment by centuries or millenniums of survival in health and vigor. It is a simple matter of mathematics to show that the intensity of light under the zenith sun in the tropics is the greatest and that the proportion of rays per unit of surface diminishes as we go north in proportion to a function of the latitude. In addition to this the further from the tropics we go the greater is the layer of air which the rays must pass through and the more of them which are absorbed. . . . Undoubtedly the Negro, when in the shade, is able to radiate heat better than whites and this enables him to keep cool in the tropics, but puts him at a disadvantage in the north where a white man can keep warmer with less clothing and less fire in the house. But it is a secondary cause enhancing the first, because when it comes to a question of light and cold, nature makes no mistake, but selects a color to exclude the light. Hence in all cold, light countries, i.e., steppes, plains and the arctics, there is pigmentation of a color in the lower end of the spectrum, red or yellow, with variations of brown, olive or copper. . . . .. All these red and yellow colors undoubtedly enable the native to conserve his heat almost as well as the white man, and at the same time, exclude the dangerous short waves." 21 Though the individual man may prosper for a time in the tropics .. 21 WOODRUFF, C. W. Effects of Tropical Light on White Men, p. 85 ff. it may be that there is some deep seated reason for the absence of third generation Europeans in India. Our experience with the polar regions is too meager to give us the basis for an opinion as to their effects on the race. The barometric pressure at sea level is 29.38. The ordinary changes in pressure are too slight to be noted. Yet most people have momentary discomfort when descending in an express elevator from the top of a high building. Serious results ensue from sudden changes of altitude. During the construction of the tunnels under the Hudson one physician is stated to have seen 2,400 cases of "caisson disease," popularly known as the "bends," resulting from working under unusual pressure; while Younghusband's account of the British expedition to Thibet gave many amusing accounts of the attempts of sea level dwellers to march and fight at high altitudes. Railroad circulars seldom mention the danger of going to the top of Pike's Peak, but physicians are better informed. Prolonged residence in high altitudes is thought to produce definite effects, inasmuch as the blood gets more oxygen and gives off more carbon dioxid. 4. Physiological Effects.-In spite of the considerable overlapping with the purely physical effects it seems wise to consider certain types of influences under this caption. Every one is conscious that his feelings vary from day to day and that they are influenced by climatic conditions. Of Buenos Aires, Dexter writes: "By the time the north wind has reached the city it has become so overcharged with moisture that everything becomes intensely damp. The effects produced in the human body are a general lassitude and relaxation, opening the pores of the skin and inducing great liability to colds, sore throat and all consequences of checked perspira tion." Of the dry winds of Colorado he says: "During the prevalence of such, the humidity is invariably excessively low, and in the dry air there seems to be set up, by the movement of the wind particles and the leaves and grasses set in motion by them, an electrical state which in some undetermined way makes havoc with the emotions." 22 In similar fashion, Huntington writes: "In eastern Turkey the hot desert wind causes the whole community to become cross and irritable. I have there seen a missionary, a man of unusual strength of character, shut himself up in his study all day, because he knew that he was in danger of saying something disagreeable. Similar reports come from Italy. 66 >> 23 Hann claims: Damp air and increased pressure have the following physiological effects:-nervous depression; quiet sleep; increased elimination of carbon dioxid; slower circulation of the blood. Dry air and decreased pressure, on the other hand, have these effects: - nervous excitement; sleeplessness; quickened pulse; a dim skin and a decreased temperature." 24 Dry cold and dry heat are relatively easy to endure. There seems to be reason to believe that the connection between climate and behavior may be more clearly understood in the future. Many students have attempted to establish the relationship but their evidence has been too vague and fragmentary to justify very definite conclusions. The contrast shown by the charts on page 37 may well lead us to expect different reactions in the residents of New York and Denver. Hellpach has collected considerable evidence showing 22 DEXTER, E. G. Weather Influences, pp. 81-82. |