[IDEM libro trigensimo sexto ad Sabinum. ] §1.6.5.prNepotes ex filio mortuo auo reccidere solent in filii potestatem, hoc est patris sui: simili modo et pronepotes et deinceps uel in filii potestate, si uiuit et in familia mansit, uel in eius parentis, qui ante eos in potestate est.
[THE SAME in the thirty-sixth book on Sabinus.] Grandsons by a son, upon the death of their grandfather, are accustomed to fall back under the power of the son, that is, of their own father; in like manner, great-grandsons and so on in succession fall either under the power of the son, if he is alive and has remained in the family, or under the power of that parent who is in power next above them.
et hoc non tantum in naturalibus, uerum in adoptiuis quoque iuris est.
And this is a rule of law not only in the case of natural descendants, but also in that of adoptive ones.