The board of trustees of the new corporation shall at first consist of the persons constituting the boards of trustees of the several institutions consolidating, and others. The number of trustees shall not exceed 45. The board of trustees shall be so classified that the term of office of one-third of its members expires each year, and unless otherwise provided in the articles of incorporation or bylaws, the successors of the trustees, as their terms expire shall be elected by the grand lodge, assembly, conference, or other legislative or representative head, at its annual meeting.