British engineer and Neo-Malthusian reformer. Married Bessie Ingham Edwards (1898), one daughter, one adopted son. Drysdale was the son of noted Malthusian activists and leaders of the Malthusian League, Charles Robert Drysdale and Alice Vickery Drysdale. After writing a series of articles for the League's journal, The Malthusian, he succeeded his father as editor in 1907. He was also the author of The Small Family System: Is it Injurious or Immoral? (1917); Small or Large Families (1917); and Neo-Malthusianism and Eugenics (1922). Drysdale met Margaret Sanger during her 1914-1915 exile in England and the two remained supportive colleagues for many years. In 1921, when his mother resigned, Drysdale took over as president of the League. The next year he organized the 5th International Neo-Malthusian Conference in London. Although committed to alleviating the plight of England's poor, Drysdale's Malthusian League remained a champion of classical economic theories and with the rising tide of socialist ideals was unable to build effective alliances with the working classes. The League also separated from the fledgling Labour Party when the latter refused to embrace the issue of family limitation. Drysdale's political beliefs hampered the effectiveness of the Malthusian League which by 1927 was barely active, though he continued to function as its head until his death.