OOP: __construct() and "extend"

Hey list, I'm writing my own class which extends upon the Memcached class (php.net/memcached). I'm a bit confused as to how the constructor works when extending a class. class caching extends Memcached { function __construct() { echo "Caching Class Construct!"; } } For something like the above code, is the Memcached constructor called? Or do I have to explicitly call it via parent::__construct() within the caching class? Thanks.