[POMPONIUS libro primo ad Sabinum. ] §28.2.8.prSi Primo herede instituto filium exheredauero, a Secundo autem substituto non exheredauero et, dum pendet, an prior aditurus sit, filius decesserit, secundum sententiam qua utimur non erit Secundus heres, quasi ab initio inutiliter institutus, cum ab eo filius exheredatus non sit.
[POMPOMIUS, Book 1 on Sabinus.] If, having appointed Primus as heir, I have disinherited my son, but have not disinherited him with respect to Secundus, the substituted heir, and the son dies while it is still pending whether the former will enter upon the inheritance, then according to the opinion we follow, Secundus will not be the heir, as if he had been invalidly appointed from the beginning, since the son was not disinherited with respect to him.
quod si in postumo filio idem acciderit, ut natus uiuo patre a quo exheredatus sit moriatur, eadem dicenda erunt de substituto, quoniam cum est natus filius, loco eius est, qui superstes est.
And if the same should happen in the case of a posthumous son, so that after being born he dies during the lifetime of the father by whom he was disinherited, the same must be said of the substitute, since when the son is born, he is in the position of one who is surviving.