Читать книгу The Book of the Pearl. The history, art, science, and industry of the queen of gems онлайн

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In 1871, Garner ascribed the occurrence of pearls in the common English mussel (Mytilus edulis) to the presence of distomid larvæ.^[60] Giard,^[61] and other French zoölogists, made similar discoveries in the case of Donax and some other bivalves. In 1901, Raphael Dubois confirmed the observations of Garner, associating the production of pearls in the edible mussels on the French coasts with the presence of larvæ of a parasite, to which he gave the name of Distomum margaritarum, and boldly announced: “La plus belle perle n’est donc, en définitive, que le brillant sarcophage d’un ver.”^[62]

Prof. H. L. Jameson, in 1902, disclosed the relation which exists between pearls in English mussels (Mytilus) and the larvæ of Distomum somateriæ.^[63] The life history of this trematode, as revealed by Dr. Jameson, is especially interesting from a biological standpoint, since it is entertained by three hosts at different times: the first host is a member of the duck family; the second is the Tapes clam (Tapes decussatus), or perhaps the common cockle (Cardium edule), which incloses the first larval stage, and the third is the edible mussel, in which the second larval stage of the parasite stimulates the formation of pearls. At the Brighton Aquarium and the Fish Hatchery at Kiel, Dr. Jameson claims to have succeeded in artificially inoculating perfectly healthy mussels with these parasites by associating them with infested mollusks, and thereby producing small pearls.