[IDEM libro nono decimo digestorum. ] §36.1.78.prScaeuola respondit, si pater filium suum impuberem ex asse scripserit heredem eique codicillis substituerit, deinde filius impubes decesserit, licet substitutio inutilis sit, quia codicillis hereditas neque dari neque adimi potest, tamen benigna interpretatione placet, ut mater, quae ab intestato pupillo successit, substitutis fideicommisso obligetur: quod si inuicem fuerunt substituti, et in fideicommisso substitutionem ualere: unoque corum mortuo qui supersunt totum accipiunt.
[THE SAME, Digest, Book 19] Scaevola answered that if a father has appointed his impuberate son as his sole heir and has substituted another to him by codicil, and then the impuberate son has died, even though the substitution is invalid because an inheritance can neither be given nor taken away by codicil, nevertheless, by a benign interpretation, it is accepted that the mother, who succeeded to the pupillus ab intestato, is bound by a trust to the substitutes; and if they were substituted to each other, the substitution is valid also in the trust, and upon the death of one of them, those who survive receive the whole.