1965 CAP (clean air package) Air Cleaner Decal?

While we are on the subject, since the hose is placed outside the filter medium of the paper filter element, what is the point of the hose in the first place? Since the PCV on the opposite valve cover sucks the air/vapor from the crankcase, this air cleaner hose is just sucking in unfiltered atmospheric air from the outside (not polluting anything whether it was hooked up to the air cleaner or not). Maybe I am missing something here.