Any person appointed and commissioned an officer of the National Guard is required to pass such tests as to his physical, moral and professional fitness as shall be prescribed by the United States. The examination to determine such qualifications for commissions shall be as prescribed by the United States. Officers shall be commissioned by the Governor, and the commission shall designate the arm, staff corps or department, and, in the case of line officers, the unit to which they are assigned.
Neb. Rev. Stat. §§ 55-137