Occupatio
The taking possession of a thing which belongs to no one (
res
nullius), with the intention of appropriating it: the property in it is thereby
ipso facto vested in him who takes possession (
De Off. i. 7,
21). Among the things of which one can become owner in this fashion are wild animals, birds,
bees, and fishes (
Inst. ii. 1, 12-16), enemies'
property on Roman soil (
ib. 17), stones and pebbles found on the
sea-shore (
ib. 18), islands which rise in the sea (
ib. 22), treasure-trove (
ib. 39), and
res
derelictae, property abandoned by its former owner (
ib. 47).