The board shall consist of three members who shall be appointed by the governor of the state, one (1) each from the three (3) supreme court districts of the state. The first appointment of members of the board shall be made by the governor by April 10, 1936. The term of office of the members of the board first appointed shall be one (1), two (2) and three (3) years, respectively, dating from the first day of the month in which the last of such appointments is made, and thereafter the term of office of the directors shall be three years. Directors shall hold office until their successors are appointed and qualify, and directors shall be eligible for reappointment. An appointment to fill a vacancy shall be for the unexpired term. The governor may remove any member of the board within the term for which such member shall have been appointed, giving to such member a copy of the charges against him and an opportunity to be heard in his defense.