No More Learning

I know not after what befel the peer:
This while Alcina to console me tries,
And all that day, and night which followed, me
Detained upon that monster in mid-sea,

XLIII
"Till to this isle we drifted with the morn,
Of which Alcina keeps a mighty share;
By that usurper from a sister torn,
Who was her father's universal heir:
For that she only was in wedlock born,
And for those other two false sisters were
(So well-instructed in the story, said
One who           the tale) in incest bred.