§ 16. By-laws. The by-laws may provide for their amendment by the board of directors; but any amendment adopted by the board shall be reported to the annual meeting of the corporation and, if not affirmatively approved thereat, shall cease to be in effect. By-laws may be adopted, repealed or amended on the affirmative vote of two-thirds of the members, stockholders or delegates voting thereon at a meeting held after due written notice setting forth the proposed action and the purpose of the meeting.