"I come to leave my shrine;
This serpent view, that with ambitious play
My staff encircles; mark him every way;
His form though larger, nobler, I'll assume,
And, changed as God's should be, bring aid to Rome."
(Ovid: Metamorphosis XV).
When in due time this salutary serpent arrived upon the island in the Tiber he began to assume his natural form, whatever that may have been;
"And now no more the drooping city mourns,
Joy is again restored and health returns."