[Caitlin]

Tissue nucleated implies there is tissue deep in the middle of the pearls.
As it turns out, the tissue inserted in the cut must consist of at least some epithelial cells from the mantle, which then organize themselves into a sack which then fills up with nacre (Strack 2006 p 116 is a very nice diagram of this process)

so don't you think tissue-stimulated is a more correct term?

Edited to say the Strack said this very thing, that tissue-stimulated is a more correct term that she prefers, in her lecture Feb 3, 2007 at the AGTA show in Tucson.