may obtain results quite different from the crude birth-rate. Thus the crude birth-rate of Buda-Pesth is much higher than that of New South Wales, but if we ascertain the birth-rate of married women at different age-periods (15 to 20, 20 to 25, etc.) the New South Wales birth-rate is higher for every age-period than that of Buda-Pesth. McLean considers that in young communities with many vigorous immigrants the population is normally more prolific than in older and more settled communities, and that hardships and financial depression still more depress the birth-rate. He further emphasizes the important relationship, which we must never lose sight of in this connection, between a high birth-rate and a high death-rate, especially a high infantile death-rate, and he believes, indeed, that "the solution of the problem of the general decline in the birth-rate throughout all civilized communities lies in the preservation of human life." The mechanism of the connection would be, he maintains, that prolonged suckling in the case of living children increases the intervals between childbearing. As we have seen, there is a tendency, though not a rigid and invariable necessity,28 for a high birth-rate to be associated with a high infantile death-rate, and a low birth-rate with a low infantile death-rate. Thus in Victoria, we have the striking fact that while the birth-rate has declined 24 per cent the infantile death-rate has declined approximately to the still greater extent of 27 per cent.
No doubt the chief cause of the reduction of the birth-rate has been its voluntary restriction by preventive methods due to the growth of intelligence, knowledge, and foresight. In all the countries where a marked decline in the birth-rate has occurred there is good reason to believe that Neo-Malthusian methods are generally known and practised. So far as England is concerned this is certainly the case. A few years ago Mr. Sidney Webb made inquiries among middle-class people in all parts of the country, and found that in 316 marriages 242 were thus limited