[PAULUS libro trigensimo quinto ad edictum. ] §1.7.23.prQui in adoptionem datur, his quibus adgnascitur et cognatus fit, quibus uero non adgnascitur nec cognatus fit: adoptio enim non ius sanguinis, sed ius adgnationis adfert.
[PAUL, on the Edict, book 35.] He who is given in adoption becomes a cognate to those to whom he becomes an agnate, but to those to whom he does not become an agnate, he does not become a cognate either; for adoption does not bring the right of blood, but the right of agnation.
et ideo si filium adoptauero, uxor mea illi matris loco non est, neque enim adgnascitur ei, propter quod nec cognata eius fit: item nec mater mea auiae loco illi est, quoniam his, qui extra familiam meam sunt, non adgnascitur: sed filiae meae is quem adoptaui frater fit, quoniam in familia mea est filia: nuptiis tamen etiam eorum prohibitis.
And therefore, if I adopt a son, my wife is not in the position of a mother to him, for she does not become an agnate to him, and because of this she does not become his cognate either. Likewise, my mother is not in the position of a grandmother to him, since he does not become an agnate to those who are outside my family. But he whom I have adopted becomes a brother to my daughter, since my daughter is in my family; their marriage, however, being also forbidden.