Cannondaleriders

I was looking at my overflow bottle today and noticed that there is no overflow hose on it just the hose off the radiator? There is no mold on the bottle for a hose. My brothers cdale has one and his production date was only 3 months later than mine. My question is do I really need this overflow hose?

mine is an early 02 and I don't have one either, and haven't had any probs.