The employees of the state institutions enumerated in Section 36-26-60 shall be governed by personnel Merit System rules and regulations, the same as other employees in state service, as administered by the State Personnel Department. Employees of such state institutions on October 1, 1966, who have been so employed for six months immediately preceding that date shall remain in their respective employments during good behavior; but nothing in this section shall be construed to prevent or preclude the removal of an employee for cause in the manner provided by law; and such employees, except for appointment, shall be subject fully to the provisions of the state Merit System Act.