In an inquiry as to the value of an executory bequest to charitable institutions, conditioned on the death of the testator's daughter without issue surviving her, was evidence that at the time of the testator's death she had been rendered incapable of bearing children admissible for the purpose of determining the amount of a deduction from the federal estate tax? Held, that such evidence was admissible. United States v. Provident Trust Co., (U. S. 1934) 54 Sup. Ct. 389.