Section, act July 3, 1918, ch. 128, § 8, 40 Stat. 756, authorized taking and use of migratory birds, nests, or eggs for scientific or propagating purposes until adoption and approval, pursuant to section 704 of this title, of regulations dealing therewith. Regulations were promulgated by Proc. July 31, 1918, 40 Stat. 1812.