PEARLS AND PEARL-DIVING 



they are most often found in certain species of oysters. 

 Very fine ones have been discovered in the ordinary 

 British fresh-water mussel, notably from the Welsh and 

 Scotch rivers; the best known of these being one that 

 was found at Conway in the seventeenth century and 

 presented by the Lord of the Manor to Catherine of 

 Braganza, wife of Charles II ; it is still preserved among 

 the Crown jewels. The sea mussels found at the mouth 

 of the Conway are still crushed for the sake of any pearls 

 they may contain. 



About a year ago a large spherical pearl was taken 

 from a Whitstable oyster ; and pearl-bearers, both mussel 

 and oyster, are so continually found off* the coast of 

 Scotland that a local fishery has more than once been 

 seriously mooted even in our own time. In the seven- 

 teenth and eighteenth centuries such an industry was 

 carried on there, over a hundred thousand pounds 1 worth 

 of pearls being shipped to France between the years 

 1760 and 1800 alone. The Chinese oyster, too, often 

 contains a very small pearl. 



In a general way, however, we can only expect to find 

 the genuine article in really warm seas and at a consider- 

 able distance from the shore, as in the case of Ceylon, the 

 East and West Indies, Central America, and the Persian 

 Gulf. The pearl-oyster proper (Mekagrlna margaritiferus) 

 has a shell that is almost semicircular and of a greenish 

 colour outside, the inside being lined throughout with an 

 unusually thick and hard nacreous coat; the two valves 

 are joined together by a very long straight hinge. Such 

 fish are found either singly or in huge clusters, clinging 



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