Tenure of Office.
Section 15
SEC. 15. Tenure of Office. — The tenure of office of the members shall be six years: Provided, That in the first appointments, the term of office of the three members appointed by the President shall be fixed as follows: one member for six years, one member for four years, and the third member for two years: Provided, finally, That no vacancy shall be filled except for the unexpired portion of the term.