The commissioners of each county shall be the executive and administrative officers of the institution district of that county, and the county treasurer shall be its treasurer. The office of county poor director is hereby abolished and the terms of the poor directors now in office are hereby terminated. The commissioners shall, however, employ each of the present paid county poor directors until his existing term of office shall expire, in the administration of this act, paying him his present annual salary, and if he now receives no fixed annual salary, then such salary as may be fixed by the commissioners.
62 P.S. § 2252