The directors shall elect from their number a president and one or more vice-presidents. They shall elect a secretary and a treasurer, who need not be directors or members of the association, and they may combine the 2 latter offices and unite both functions and titles in one person. The treasurer may be a bank or any depository and, as such, shall not be considered as an officer, but as a function of the board of directors. In such case, the secretary shall perform the usual accounting duties of the treasurer, excepting that the funds shall be deposited only as and where authorized by the board of directors. Any vacancy in any office, other than that of director, shall be filled by the board of directors.