Calling static method from object array variable

In PHP you can call a class's static method from an object instance (which is contained in an array) like this:

$myArray['instanceOfMyClass']::staticMethod(); // works

But for some reason when I use the $this variable, I get a parsing error. E.g:

$this->myArray['instanceOfMyClass']::staticMethod(); // PARSING ERROR

Just to illustrate what I mean:

class MyClass{
    public static function staticMethod(){ echo "staticMethod called\n"; }
}

$myArray = array();
$myArray['instanceOfMyClass'] = new MyClass;
$myArray['instanceOfMyClass']::staticMethod(); // works

class RunCode
{
    private $myArray;

    public function __construct(){
        $this->myArray = array();
        $this->myArray['instanceOfMyClass'] = new MyClass;
        $this->myArray['instanceOfMyClass']::staticMethod(); // PARSING ERROR
    }
}

new RunCode;

Any ideas on how to get around this?