Last night while taking off my oil filler cap which has become a bit stiff I accidentally banged this guy and broke it:
Some kind of breather no doubt. The break is about a half inch downhill from the elbow. One thought is to get some sort of sheet rubbery gasket material, wrap it a bit and use an hose clamp to gently hold it in place. I understand from he who shall not be named that removing if from the valve cover gasket is a serious PITA.
S'funny though, looking at the pic I see what looks like a crack running diagnolly across the vertical part. That part seemed fine when I pieced it back together. For now I put some aluminum tape around it but that's not a good solution.
Who knows, renewing the valve cover gasket might not be a bad idea, getting a new tube could be good all in all.