[Zope] LocalFS question

How do you access an individual object in a LocalFS? By that, I mean: If I wanted the last_mod time of any Zope object, I could say <dtml-var "object.subobject.bobobase_modification_time">. However, if you try to do the same thing with a LocalFS object, i.e. <dtml-var "localfs_object.localfs_subobject.bobobase_modification_time">, you get the error NameError: localfs_subobject This leads me to believe that LocalFS subobjects are not really objects. But then how does the Zope management interface deal with them, and how can I?