Rensselaer Semi-Weekly Republican, Volume 41, Number 22, Rensselaer, Jasper County, 27 November 1908 — Tapeworms Make Pearls. [ARTICLE]

Tapeworms Make Pearls.

Prof. Herdman’s recent Investigations on the subject of pearl formation have yielded some Interesting conclusions. In the great majority of cases it appears that the pearl is due to the presence In the oyster of a marine tapeworm. When the spherical larva of the worm dies nacreous matter is deposited round it, and the resulting mass is known as a pearl. The life history of the tapeworm is continued in the bodies of certain species of file fish which prey on the oysters. These file fish, again, are devoured by fishor sharks. In these latter the tapeworm becomes mature, and sets free numerous embryos into the sea. These finally enter the oysters, and so complete the life cycle. The small so-called “seed” pearls are caused by the deposition of necreous matter round small crystals formed in certain muscles of the oyster. Perhaps the most important result of Prof. Herdman’s work from the scientific standpoint is the establishment of a marine biological station at Galle for further research. —London Globe.