321.06  Civil service.--The Department of Highway Safety and Motor Vehicles is hereby empowered and directed to make civil service rules governing the employment and tenure of the members of the highway patrol. All persons employed as said patrol officers shall be subject to said civil service rules and regulations, and any amendment thereto which may thereafter from time to time be adopted. The department may, for cause, discharge, suspend or reduce in rank or pay, any member of said highway patrol by presenting to such employee the reason or reasons therefor in writing, subject to the civil service rules and regulations of the department, and subject to the review of the Governor and Cabinet, as head of the department who shall serve as a court of inquiry in such cases and shall hear all complaints and defenses, if requested by such employee. Their decision shall be final and conclusive. Such civil service rules or regulations shall be subject to the revision of the Legislature in the event civil service rules adopted by the department are declared unlawful or unreasonable.