URBAN POPWTION. No feature in the rapid increase in the population of civilized countries during the nineteenth century has been more marked than the growth of cities, both in the older European countries and in the newer coun tries whither that European population has mi grated. The results of the last censuses of for eign countries are not yet in every case avail able, and therefore the following figures speak for 1800 and 1S90. or the nearest census years. The countries are arranged in the order of the proportion of urban population in 1590 in the fol lowing table.
The following figures illustrate the degree to which the growth of city population during the nineteenth century in nearly all parts of the civilized world outstripped that of population as a whole.
SEX. About half the probable population of the world has been enumerated with relation to sex. From the results it appears that about 50.3 per cent are male and 49.7 per cent. female.
In Europe alone among the great divisions of the earth's surface do the females outnumber the males, there being on that continent among the enumerated population about 49.4 per cent. male, and 30.6 per cent. females. The numerical excess of females in Europe is much greater than the excess of male, in the continents to which migra tion ha, mainly gone, such as America and Aus tralia, and therefore it follows that in the eoun tries representing Caucasian or white civilization female, outnumber the males. But in most other parts of the world for which we have informa tion the reverse is trite. Thus in British India 50.9 per cent.. in the tributary States 51.7 per cent.. and in Japan 50.5 per cent. of the popula tion are male. The excess of males in these coun tries more than offsets the excess of females in all Europe. It seems likely that in China, which contains the largest body of population, for which we have no information, as in India and Japan. the males outnumber the females. It is even suggested by the foregoing facts that the Occi dental civilization of Europe and America, so far as the proportion of the sexes is not disturbed by migration. tends to establish a slight excess of females, while the Oriental civilization of India. China, and Japan tends to the reverse relation. In every ease. however, where migration is not an important factor, the departure from numerical equality is slight and relatively insignificant.
AGE. It is usual for a census to report the numb r of persons of each year of age, or at least the number falling within certain wider age limit,. In large population groups the true num ber of persons living at any year of age is larger than the true number of persons at the next higher year, this being due. to the fact that each such group as it advances from infancy to oil age is steadily depleted by death. if the group is receiving a large number of immigrants. this would tend to neutralize for certain age groups the wasting away through death. but immigration is seldom. if ever, sufficient in amount to balance the losses from mortality. The births in succes sive years also vary in number. and thus the ini tial size of these successive groups differs, but neither this cause alone nor this combined with immigration and other minor disturbing factors makes it likely that the true number of persons in a country at any one year of age is ever smaller than the true number at the next greater year of age. The reported number very often
is greater, this difference between the true and the asserted number being due to inaccuracy in the statements of age made in answer to the in quiries of the census enumerator. These inac curacies vary with the degree of education and the economic position of the class reporting. Where they exist in large numbers they are indi cated by a disproportionate number of individuals reported with ages at multiples of 5, and espe cially of 10. Internal evidence of the relative ac curacy with which ages are reported, and per Imps indirectly of the relative accuracy with which other census questions are answered, may be found by measuring this concentration of re ported ages on multiples of 5 and 10. The true number of persons in a community aged 30, 35, 40, 45, 50, 55, and GO is probably about one-fifth of the total number whose age is reported as be tween 2S and 62, inclusive. The per cent. by which the reported number of these seven ages exceeds the estimated number affords a measure of the irregularity of the age distribution and so of the probable error in the returns. Measured by this test there were 1,670,000 persons in the United States in 1890 and 1,250,000 in 1900 between 2S and 62 years of age, whose ages were reported erroneously as a multiple of 5. The reported number in 1890 was 38 per cent. and in 1900 23 per cent. in excess of the estimated true number.
Perhaps the best single figure indicating the age composition of a population group is the median age, or an age such that half the members of the group are above and half are below it. For the white population of the United States this median age increased almost steadily during the nineteenth century from 16.0 in 1800 to 23.4 in 1900, the increase being due in part to the in creased longevity of the adult population and in part to the steadily decreasing proportion of chil dren. The median age of the population in the South (South Atlantic and South Central divi sions) was 19.5 years in 1900. that of the popu lation in the North (North Atlantic and North Central divisions) was 24.5, a difference of 5 years.
The proportion of the population falling with in various age classes is of importance for itself and as indicating reasons for other statistical differences between population groups. Thus in Indian Territory 15.3, in South Carolina 15.2, and in Utah 15.1 per cent. of the population are under 5, these being the regions of the United States in which the proportion of children is greatest. At the other extreme there are the District of Columbia, with 8.3 per cent., Cali fornia, with 8.5. and Nevada, with 8.9. The greatest proportion of elderly persons is found in the northern New England States, Vermont having 8.1, New Hampshire 7.9. and Maine 7.9 per cent. of the population over 65 years of age.