Perlin Noise only works in a single axis?

I've been messing around with perlin noise and meshes to create procedural terrain. It didn't work properly so I copied the code from a tutorial here in order to better visualise it. The same problem reoccurs, as shown in the pictures below (his then mine). Have they changed how the perlin noise function works in Unity? Thanks.

My Code:

 #pragma strict
 var size : int = 10;
 var cube : GameObject;
 var scale : float = 6.5;
 var move : boolean = false;
 
 function Start () {
     for(var x=0;x<size;x++){
         for(var z=0;z<size;z++){
             var c = Instantiate(cube, Vector3(x,0,z),Quaternion.identity);
             c.transform.parent = transform;    
         }
     }
     for(var child:Transform in transform){
         var height = Mathf.PerlinNoise(child.transform.position.x/scale,child.transform.position.y/scale);
         child.renderer.material.color = Color(height,height,height,height);
     }
 }
 
 function Update () {
     for(var child:Transform in transform){
         var height = Mathf.PerlinNoise(child.transform.position.x/scale,child.transform.position.y/scale);
         child.renderer.material.color = Color(height,height,height,height);
     }
     if(move == true){
         for(var child:Transform in transform){
             height = Mathf.PerlinNoise(child.transform.position.x/scale,child.transform.position.y/scale);
             child.transform.position.y = height;
         }
     }
 }