The climate of the United States exercises, according to certain sociologists, on the first generation of European immigrants, a deleterious influence in regard to fecundity. The decrease in the fecundity of the American woman has been charged to various anti-social causes (abortion and prevention of conception) and to a "nervousness" induced by the climate. A seemingly fair test of the influence of the climate would be a race elsewhere fecund, and whose religion encourages fecundity, decreasing in the first generation after immigration to the United States. Such a race is the Jewish. According to Gihon's analysis of the United States census of 1890[173] the Jewish birth rate is diminishing. From the mothers born in the United States the average is 3·56 children, as against 5·24 for those born in Germany, 5·36 for those in Russia and Poland, 5·27 for those in Hungary, and 5·44 for those in Bohemia. These figures, however, do not demonstrate the influence of climate, but of environment. The Jew, unlike the earlier American colonists, is not exposed to the stress of frontier life. He has a more favourable mental and physical environment than on the continent of Europe. This fact, therefore, does not demonstrate the effects of climate, but is really chargeable to climate, food, soil, and other factors constituting environment. That climate cannot be considered apart from these factors is shown, as I pointed out several years ago, by the fact that the United States surveyors in Minnesota reported to the national authorities that it was impossible to live the whole year in that state because of the extremely cold winter. Now, not only do people live and cultivate the soil throughout the entire state, but large cities have sprung up still farther north, and the country around has become well populated. Hence, in dealing with influences of climate, change of food and hygienic conditions must be taken into account. The error of the American surveyors as to the acclimatisation of the white race in cold climates has been emphasised as to the tropics and arctics. Here, however, the same error has been demonstrated by very careful researches. The experience of the Arctic regions as to necessity for change in diet and hygiene has been fully borne out by observations on the Anglo-Saxon in the tropics. The early experience of the English in India, upon which a fatal prognosis as to the future of British India was based, turns out to have been erroneous.