IPhone : Couldn't make a particle follow a path in spriteKit

This is the animation in XCode SKEmitter editor (I want to achieve this on the iPhone) :

This is the animation on the iPhone (I don't want this animation):

Using this code:

    let sparkEmmiter = SKEmitterNode(fileNamed: "fireflies.sks")
    self.addChild(sparkEmmiter) // self is a SKScene

    var circle: CGPathRef? = nil
    circle = CGPathCreateWithEllipseInRect(CGRectMake(400, 200, 200, 200), nil)
    let followTrack = SKAction.followPath(circle!, asOffset: false, orientToPath: true, duration: 3.0)
    let followTrackForever = SKAction.repeatActionForever(followTrack)
    //sparkEmmiter.runAction(followTrackForever)
    sparkEmmiter.particleAction = followTrackForever;

I tried both runAction and particleAction by referring to this question, but it doesn't work as I wanted it to...