Mortality.—In the civilised countries of Europe the death-rate in the twentieth century varies between 15 and 32 per mille. Among the chief causes of transient variations in the death-rate are: war, civil disorders, and rise in prices. A rise in the price of the necessaries of life affects the lower classes of the population more especially, but its influence upon the general death-rate is trifling. Death-rate varies in accordance with occupation. The lower classes have a higher death-rate than the upper; the weekly wage-earners have a higher death-rate than the rest of the population; and mortality is greater in the towns than it is in the country. Of late years, there has been a gradual decline in the death-rate, the decline in the towns being proportionately greater than the decline in the country districts; in this case also the decline must be attributed mainly to the advance in medical science.

The Productive Age and the Unproductive Age.—The distinction of the productive age from the unproductive age is a matter of great importance. The former extends from the age of 15 to the age of 65; the latter, the unproductive age, comprises the years before the age of 15 and those after the age of 65. Certain other classifications of the population, such as the distinction of those of an age for school-attendance from those at other ages (those of the former age comprising about one-sixth of the population), and the distinction between youthful and adult criminals, are of no interest in relation to our special inquiry.

Classification of the Population according to Age.—In the civilised countries of modern Europe, persons at ages of 0 to 10 comprise about 24 per cent. of the population; those at ages 10 to 20 comprise about 20 per cent.; and those at ages 20 to 30 comprise about 16 per cent. of the population. Those under the age of 15 years comprise about 30 per cent. of the population, each year of life corresponding to from 2 to 3 per cent.; infants (those under 1 year) making up 3 per cent., and each year of life after that only a little more than 2 per cent. At all ages under 15 the boys are more numerous than the girls.

The age-pyramid of the population has a form which depends upon the birth-rate. When the birth-rate is higher, or the excess of births over deaths greater, the base of the pyramid is comparatively wide. Thus, in the majority of the civilised states of Europe, about 30 per cent. of the population consists of those under 15 years of age; but in France, where the birth-rate is exceptionally low, those under 15 years of age comprise a much smaller proportion of the total population.

In the country districts, the age-class of the children and the age-class of the old both contain proportionately larger numbers than the same age-classes in the towns. In the large towns and the manufacturing districts, there is an especially large proportion of persons of about 20 years of age. There are three reasons for this: first, the birth-rate is higher in the country districts; secondly, there is a drift from the country to the towns of persons of an age to earn a living; and, thirdly, a proportion of those who have grown old in the towns find their way back to the country.

The Excess of Women.—All the civilised countries of twentieth-century Europe contain more women than men. For every 1000 males there are invariably more than 1000 females. The excess of females is not usually greater than 5 per cent. Only in certain uncivilised countries of Europe do we find no excess of females. Whether we compare the total female population with the total male population, or compare only males and females of a marriageable age, the result is the same; the females are always in excess. Even in those countries in which women are comparatively less numerous, we still find an excess of women of a marriageable age.

This excess of women depends upon the following causes:—In civilised countries more boys are born than girls. The average excess of male births over females is 106:100. (In the case of illegitimate children, the excess of male births is not so great as in the case of legitimate children.) But in males the death-rate is much higher than it is in females. Especially high is the death-rate among male infants (in the first year of life), and among males during the ages at which they are competent to earn a livelihood. The reason given for the higher mortality of male infants is that their powers of resistance are inferior to those of female infants; during the productive years of life the death-rate of males is higher because, on the one hand, they have a far greater mortality than women from diseases of occupation, and, on the other hand, during this period of life males suffer far more than females from the effects of alcoholism, of criminality, and of various other factors exercising an unfavourable influence upon their death-rate.

Thus the excess of women is closely associated with that peculiarity of the modern system of production in virtue of which far more men than women are engaged in the work of production. This is obvious from the consideration that the death-rate of wage-earning women is higher than that of other women, and from the consideration that in great towns the ratio between the death-rates of the respective sexes is very different from what it is in the country districts. The excess of women is one of the causes of the failure of so many women to marry, of the birth of so many illegitimate children, of the wide diffusion of prostitution, &c. But it would be quite erroneous to attribute these various phenomena of our sexual life exclusively to the prevalent excess of women.

If in any country we desire to diminish the excess of women, it is necessary not merely to lessen the emigration of males, but also to diminish the death-rate of male children. This may be effected by reducing infant and child mortality in general, for measures that accomplish this reduction will lower the death-rate of boys to a greater extent than the death-rate of girls; for the higher the death-rate the greater the effect we can produce by measures effecting its diminution. Hence child-protection, the principal means for the diminution of infant and child mortality, is not only an important part of our campaign against the excessive mortality of male children, but will tend to redress the existing numerical inequality between the sexes, and thus to ameliorate the conditions of our social life.

The regulation of the birth of boys and girls (the determination of sex) would be an important means for the restoration of a proper numerical balance between the sexes, and would therefore be of value, not merely to interested individuals, but also to society at large. Unfortunately, contemporary science is not even in a position to ascertain the sex of the infant before birth; and still less are we in possession of such a knowledge of the determinants of sex as might enable us to procreate boys or girls at will. Should the astounding advance in medical science eventuate in the solution of this problem, it will then be in our power to restore the proper numerical balance of the sexes.