Section, act May 27, 1921, ch. 14, §407, 42 Stat. 18 , which directed the Secretary to make rules and regulations necessary for the enforcement of sections 160 to 171 of this title was omitted in view of the repeal of sections 160 to 171 of this title by Pub. L. 96–39, title I, §106(a), July 26, 1979, 93 Stat. 193 .