The poor wee lassie's navel string, of course. Where else should it be but hung on her own little tree?
9 seconds sound clip from the The Wicker Man (1973) movie soundboard.
You can hear this line at 00:33:46 in the Blu-ray version of the movie.
Quote context
[...]
- They're just a wee bit late with the headstone.
- What on earth's that? It looks like a piece of skin.
- Where does your minister live?
- Anyone'd think you didn't want to get better.
- Now, in he goes! And out he comes.
[...]