The donee of a power of appointment exercised it by will in favor of the persons who would have taken exactly the same interests in default of appointment, and who declared their election to decline the appointment and take by the provision in default of appointment in the will of the donor. Suit was brought for additional federal estate taxes covering the property to which the power applied, under a statute levying such a tax upon "any property passing under a general power of appointment exercised by the decedent . . . by will . . . . " Held, that the property subject to the power had not passed under the appointments made, since the assent of the appointee was necessary to make the transfer under the power complete, and the appointees had here seasonably refused to take under the appointment and elected to take directly from the donor. Helvering v. Grinnell, 294 U.S. 153, 55 Sup. Ct. 354 (1935).