The board of aldermen, by ordinance, may create, change, and abolish offices, departments, or agencies, other than the offices, departments, and agencies established by this Charter. The board of aldermen by ordinance may assign additional functions or duties to offices, departments, or agencies established by this Charter, but may not discontinue or assign to any other office, department, or agency any function or duty assigned by this Charter to a particular office, department, or agency. (Acts 1951, Ch. 539, § 18)