[POMPONIUS libro quinto ad Sabinum. ] §7.1.69.pruel inutilium alia summittere, ut post substituta fiant propria fructuarii, ne lucro ea res cedat domino.
[POMPONIUS libro quinto ad Sabinum.] or to substitute other animals in place of useless ones, so that after they have been substituted, they become the property of the usufructuary, lest this matter should result in a gain for the owner.
et sicut substituta statim domini fiunt, ita priora quoque ex natura fructus desinunt eius esse: nam alioquin quod nascitur fructuarii est et cum substituit, desinit eius esse.
And just as the substituted animals immediately become the owner's property, so also the former ones, by the nature of fruits, cease to be his; for otherwise, what is born belongs to the usufructuary, and when he substitutes it, it ceases to be his.