In the skilled artisan class there is also good reason to believe that the voluntary limitation of families is constantly becoming more usual, and the statistics of benefit societies show a marked decline in the fertility of superior working-class people during recent years; thus it is stated by Sidney Webb that the Hearts of Oak Friendly Society paid benefits on child-birth to 2472 per 10,000 members in 1880; by 1904 the proportion had fallen to 1165 per 10,000, a much greater fall than occurred in England generally.
The voluntary adoption of preventive precautions may not be, however, the only method by which the birth-rate has declined; we may have also to recognize a concomitant physiological sterility, induced by delayed marriage and its various consequences; we have also to recognize pathological sterility due to the impaired vitality and greater liability to venereal disease of an increasingly urban life; and we may have to recognize that stocks differ from one another in fertility.
The delay in marriage, as studied in England, is so far apparently slight; the