Section, act Aug. 20, 1912, ch. 308, § 15, as added May 31, 1920, ch. 217, 41 Stat. 726; amended May 16, 1928, ch. 572, 45 Stat. 565; July 7, 1932, ch. 443, 47 Stat. 640; Mar. 26, 1934, ch. 89, 48 Stat. 486; Apr. 1, 1942, ch. 207, §§ 1, 4, 56 Stat. 190, 192; Pub. L. 88–60, §§ 1, 7, July 8, 1963, 77 Stat. 77, 78; Pub. L. 91–358, title I, § 155(a), July 29, 1970, 84 Stat. 570, related to rules and regulations to prevent dissemination of dangerous plant diseases and insect infections and infestations in the District of Columbia.