The pearl; isolation of outside bodies by molluscs: evolution of the graft and the pearl-sac in Pinctada margaritifera (Mollusca, Lamellibranchia)

摘要

The production of a cultured pearl needs a 'graft', i.e. the introduction into the recei- ver nacre's pearl pocket of an aragonite bead and a mantle piece from a donor nacre. The contribution of the external epithelium of the graft is essential to the constitution of the pearl sac. This secretory sheath is produced within about twenty days; it is monocellular and exhibits four cell types. The other tissues of the graft rapidly degenerate. Conjunctive and hemocytic reactions of the receiver mollusc are described.