[AFRICANUS libro quarto quaestionum. ] §28.2.16.prSi filius heres institutus sit omisso postumo filioque substitutus nepos ex eo sit, si interim moriatur filius, postumo non nato nepotem tam patri quam auo suum heredem futurum.
[AFRICANUS, Book 4 of Questions.] If a son has been instituted as heir, a posthumous child being passed over, and a grandson by him has been substituted for the son, if the son dies in the meantime, and the posthumous child is not born, the grandson will be a self-successor both to his father and to his grandfather.
quod si nemo filio substitutus sit et solus ipse institutus sit, tunc quia eo tempore, quo is moriatur, certum esse incipit neminem ex eo testamento heredem fore, ipse filius intestato patri heres existet: sicut euenire solet, cum sub ea condicione, quae in ipsius potestate erit, filius heres institutus, prius quam ei pareret, moriatur.
But if no one has been substituted for the son, and he himself alone has been instituted, then, because at that time when he dies, it begins to be certain that no one will be an heir under that will, the son himself will stand as heir to his intestate father: just as is accustomed to happen when a son, instituted as heir under a condition which is within his own power, dies before he complies with it.