More Mind Boggling Questions

Today I was reading a children's rhyme called The House That Jack Built. You know how it goes:

This is the house that Jack built.
This is the malt that lay in the house that Jack built.
This is the rat that ate the malt that lay in the house that Jack built.
This is the cat that chased the rat that lay in the house that Jack built.
This is the dog that worried the cat, that chased the rat, that ate the malt, that lay in the house that Jack built.
etc... etc... etc....

Well, at the end of it all, my daughter looks up at me and asks "Who's Jack?"