"In the four centuries between Virgil and Servius the meaning and source of Virgil's branch of gold were forgotten. But people, and Servius himself, knew of another bough, near Aricia, and located (conjecturally?) Virgil's branch of gold in that district. Servius, then, in his commentary on the _Æneid,_ after the manner of annotators in all ages, talks much about the boughs of a certain tree in a certain grove, concerning which Virgil makes no remark. Virgil, as we shall see, was writing about a golden branch of very peculiar character. Knowing, like the public opinion of his age, something about quite other branches, and nothing about Virgil's branch, Servius tells us that, in the grove of Diana at Aricia, there grew a tree from which it was unlawful (_non licebat_) to break a bough. If any fugitive slave, however, could break a branch from this tree, he might fight the priest, taking his office if successful. In the opinion of Servius the temple was founded by Orestes, to the barbaric Diana of the Chersonese, whence he had fled after a homicide. _That_ Diana received human sacrifices of all strangers who landed on her coasts. The rite of human sacrifice was, in Italy, commuted, Servius thinks, for the duel between the priest and the fugitive slave, Orestes having himself been a fugitive. The process is, first a Greek wanderer on a barbarous coast is in danger of being offered, as all outlanders were offered, to the local goddess. This rite was a form of _xenelasia_, an anti-immigrant statute. Compare China, the Transvaal, the agitation against pauper immigrants. Having escaped being sacrificed, and having killed the king in an unfriendly land, Orestes flies to Italy and appeases the cruel Diana by erecting her fane at Aricia. But, instead of sacrificing immigrants, he, or his successors, establishes a duel between the priest and any other fugitive slave. Servius then, not observing this, goes off into an allegorising interpretation of Virgil's branch, as worthless as all such interpretations always are.
"The story about Orestes appears to myself to be a late 'ætiological myth,' a story invented to explain the slaying of the slayer--which it does not do; in short, it is an hypothesis. The priesthood is open not to men flying the blood feud like Orestes, but only to runaway slaves. The custom introduced by Orestes was the sacrifice of outlanders, not of priests. The story has a _doublette_ in Pausanias. According to Pausanias, Hippolytus was raised from the dead, and, in hatred of his father, and being a fugitive, he went and reigned at the Arician grove of the goddess.