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

Peculium is called so as if it were "small money" or a "small patrimony" (Digest 15.1.5, § "peculium"). This applies to a son of a family, that is, or a slave (Institutes 4.6, § "actiones"). It is not the father’s (Digest 50.16.182; Code 3.28, last law in the end). But at present, he speaks of the son of a family. His peculium is threefold: Castrense military fund, quasi-castrense quasi-military fund, and Paganum civil/private fund (Code 3.28, last law in the opening). It is called Castrense because it was acquired by the son of a family on the occasion of military service (Digest 49.17.11; Code 12.36.1). Quasi-castrense is that which is granted as if to soldiers, such as to advocates (Code 3.28, last law). (For these also are said to be in a certain way military (Code 2.6.14).) And to clerics (Code 1.3.38). The Paganum is twofold: Profectitium derived from the father's estate, which has proceeded from the property of the father (Digest 23.3.5, in the opening); and Adventitium acquired from other sources, which the son of a family has acquired outside of the aforementioned causes through the liberality of fortune or his own labors (Code 6.61.6, § 1). In castrense and quasi-castrense peculium, the son is in the place of the father (Digest 14.6.2). The son has the ownership of the adventitium, the father has the usufruct (Code 6.61.6). The father has full right over the profectitium (Institutes 2.9, § 1).