Come to think of it, that's how trees are. The root system is kind of an upside down version of the branches.
Actually I was making a joke... There's the one about the lady who claimed the world is flat and it rests on the back of four giant elephants, all standing on the back of a giant turtle. A young man asked what the turle stands on. Another turtle, she says. And what does that one stand on? "You can't fool me, young man," she says, "It's turtles all the way down."