years, owing to the composition of the population, has its birth-rates momentarily increased and its death-rates diminished—the birth-rates because there are more people relatively at the child-producing ages, and the death-rates because the whole population is younger, than in older countries. It appears quite unnecessary to elaborate this point. The rates of the excess of births over deaths in a country which is receiving a large immigration must be quite abnormal compared with a country in a more normal condition, while a country from which there is a large emigration, such as Ireland, must tend to show a lower excess than is consistent with a normal condition. This explanation, it may be said, does not apply to England, since it is a country which has not been receiving a large immigration or sending out, except occasionally, a large emigration. England, however, must have been affected both ways by movements of this character. It received undoubtedly a large Irish immigration in the early part of last century, and in more recent periods the emigration in some decades, particularly between 1880 and 1890, appears to have been large enough to have a sensible effect on both the birth-rate and the rate of the excess of births over deaths. This effect would be continued down into the following decade, and the consideration is therefore one to be taken note of as accounting in part for the recent decline in birth-rates in England.
In addition, however, it is not improbable that there was an abnormal increase of population in the early part of last century, due to the sudden multiplication of resources for the benefit of a poor population which had previously tended to grow at a very rapid rate, and would have grown at that rate but for the checks of war, pestilence and famine, on which Malthus enlarges. The sudden withdrawal of the checks in this view would thus be the immediate cause of the singularly rapid growth of population in the early part of last century. It is quite in accordance with this fact that a generation or two of prosperity, raising the scale of living, would diminish the rate of growth as compared with this abnormal development, without affecting in any degree the permanent reproductive energy of the people,
3. It is also obvious that one explanation of the decline in birthrate, and of the rate of the excess of births over deaths, may also be the greater vitality of the populations concerned, so that the composition of the population is altered by an increase of the relative numbers of people not in the prime of life, so altering the proportion of the people at the child-producing ages to the total. This would be too complex a subject for me to treat in the course of a discursive address. Nor would it explain the whole facts, which include, for instance, an almost stationary annual number of births in the United Kingdom for more than ten years past, notwithstanding the largely increased population. But the case may be one where a great many partial explanations contribute