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.