The Governor may, by and with the advice and consent of the Senate, appoint for each county in the State a county auditor, who shall hold his office for a term of four years and until his successor is appointed and qualified, and the Governor may require such bond from each such officer as he may deem necessary. When any auditor for any reason fails to complete his term of office, his successor shall be appointed initially for the unexpired portion of the term for which his predecessor was appointed.