Iul. Pacii Iuriscons. in L. frater à fratre D. de condictione indebiti, commentarius

That which a father has separated from his own patrimony and granted to the son under the name of peculium is correctly called peculium. But what the son of a family has outside of that cause from paternal goods is called fatherly money, by the argument of Digest 15.1.4, in the opening. Now, since the son has the administration of the profectitium peculium granted to him by his father (Digest 15.1.46), he cannot donate it (Digest 2.14.28). But he can alienate it for another cause, such as by giving a loan. For he can lend from the peculium as much to an outsider (Digest 12.1.2, § penultimate) as to the father in whose power he is (Digest 15.1.1, § "quaesitum"). And to a brother who is in the same power (Digest 15.1.1, in the opening). These things have a place while the father lives. For upon his death, when the son becomes a head of a family original: "paterfamilias" and of his own right, he ceases to have a peculium (Institutes 1.16, § 1; Code 3.28, last law, § last), because a head of a family is not said to have a peculium, but a patrimony or goods (Digest 50.16.182). Moreover, the profectitium peculium is recalled to the community, and together with other hereditary things (for this too is hereditary), it is divided (Digest 10.2.1; 10.2.4; 10.2.12; 10.2.13). Formerly, adventitia were also brought into collation (Code 6.20.4; Digest 37.6.1, § "si sub cond."). But Justinian amended this (Code 6.20, last law).