The question in this case is that of the construction of § 402 (c) of the Revenue Act of 1921, c.,‘136, 42 Stat. 227, 278, a provision similar to that of § 402 (c) of the Revenue Act of 1918, c. 18, 40 Stat. 1057, 1097, which has already been construed by this Court, and, in this view, there being no question of the constitutional authority of the Congress to impose prospectively a tax with respect to transfers or trusts of the sort here involved, the judgment of the Circuit Court of Appeals for the Seventh. Circuit is reversed upon the authority of May v. Heiner, 281 U. S. 238.