It is well known that a decline in the birth-rate set in about forty years ago in this country, and has gone on steadily ever since, till the fall now amounts to about one-third of the total births. It thus corresponds very nearly to the fall in the death-rate during the same period. It is also well known that this decline is not evenly distributed among different classes of the people. Until the decline began, large families were the rule in all classes, and the slightly larger families of the poor were compensated by their somewhat higher mortality. But since 1877 large families have become increasingly rare in the upper and middle classes, and among the skilled artisans. They are frequent in the thriftless ranks of unskilled labour, and in one section of well-paid workmen--the miners. The highest birth-rates at present are in the mining districts and in the slums. The lowest are in some of the learned professions. In the Rhondda Valley the birth-rate is still about forty, which is double the rate in the prosperous residential suburbs of London. In the seats of the textile industry the decline has been very severe, although wages are fairly good; among the agricultural labourers the rate is also low. It will be found that in all trades where the women work for wages the birth-rate has fallen sharply; the miner's wife does not earn money, and has therefore less inducement to restrict her family. In agricultural districts the housing difficulty is mainly responsible; in the upper and middle classes the heavy expense of education and the burden of rates and taxes are probably the main reasons why larger families are not desired. We may add that in almost all the professions old men are overpaid and young men under-paid. Mr. and Mrs. Whetham[18] have found that, before 1870, 143 marriages of men whose names appear in 'Who's Who' resulted in 743 children, an average of 5.2 each; after 1870 the average is only 3.08. Celibacy also is commoner among the educated. 'From the reports issued by two Women's Colleges, it appears that, excluding those who have left college within three years or less, out of 3000 women only 22 per cent. have married, and the number of children born to each marriage is undoubtedly very small.' The writers consider that this state of things is extremely dangerous for the country, inasmuch as we are now breeding mainly from our worst stocks (the feeble-minded are very prolific), while our best families are stationary or dwindling. Without denying the general truth of this pessimistic conclusion,[19] it may be pointed out that the miners are, physically at least, above the average of the whole population, and that the very low birth-rate of residential districts is partly due to the presence in large numbers of unmarried domestic servants. The death-rate of the slums is also very high.