The affairs of the various administrative departments of the City shall be administered by the officers, employees, departments, boards and commissions set forth in this Administration Code and by such other officers, employees, departments, boards and commissions as may be provided by other ordinances, all of whom shall be appointed by the City Manager, unless otherwise provided by law, and hold office at his pleasure, provided that the Manager need not appoint or employ any officer or employee herein provided for when the business of the City does not require it. The duties of such officers, employees, departments, boards and commissions shall be as provided in this Administration Code or as provided by other ordinances of the City or by the laws of the State.
(1958 Code § 2.29)