He or she selected by the Benchers (board of governors) of the Society, who in turn are mostly elected by the Society's members, with a few "lay Benchers" appointed by the provincial government.
He or she is selected by, and from among, the Benchers, who comprise "Convocation"-in effect, the Society's board of governors. The Benchers in turn are mostly elected by the Society's members, with a few "lay Benchers" appointed by the provincial government.