The business of every such society shall be managed and conducted by a board of not less than five directors, who shall be members in the society, and shall be annually elected at such time and place as shall be provided in the by-laws thereof. One of the directors shall be chosen president and one treasurer, and such directors and officers shall hold their respective offices until their successors are duly qualified. The society shall also have a secretary and such other officers, agents and factors as may be necessary to carry on its business, and shall choose them in the manner prescribed in the by-laws thereof.