a mechanism for selectively activating a plurality of downhole pathways is disclosed . the method includes a casing segment which includes a plurality of casing ribs , a valve which includes a sleeve coupled for movement between an open and normally closed position , a rocker member mounted to the sleeve , a dart for pumping in hole including a dart profile matched to the rocker member profile such that the dart profile couples to the rocker member profile when in close proximity and , in turn , the sleeve moves from the closed position to the open position .