PELECYrODA. 35 



the one case, an entire fish, and in the other a small crab, have 

 been so enclosed (see side table-case E). 



The most ancient and, even at the present day, one of the most 

 important of the pearl fisheries is that carried on on the western 

 shores of Ceylon. " The Banks," or spots on which the oysters 

 grow, are at an average depth of 30 to 60 feet, and extend several 

 miles along the coast. The oysters, which shonld be six or seven 

 years old when collected, are gathered in baskets by native divers 

 and hauled up by ropes into small boats. The shells are then 

 brought to land and placed upon the ground to die and putrefy, 

 and then minutely examined for the pearls. As many as two 

 million oysters have been brought ashore on one day ; but the 

 number obtained varies very much according to the state of 

 the banks. A small proportion of the oysters contain pearls ; 

 in some only very small ones (seed or dust-pearls as they are 

 called) are found, and very few contain pearls larger than a pea, 

 that are so highly valued. In his account of the pearl-fishery 

 of Ceylon the Kgjjj.,. .Jani-5- - Coiiifee/ says that he -saw the 

 operation 'of sorting the pearls performed; the produce of 

 17,000 oysters weighed only f lb. and was contained in a vessel 

 smaller than a common soup-plate. Out of that quantity there 

 were not found two fine perfect pearls ; all of the largest were 

 slightly deformed, rugged and uneven, but of the smaller sizes many 

 were round and perfect. The chief qualities which regulate the value 

 of pearls are size, roundness, and brilliancy of lustre. Of the smallest 

 kind several may be bought for a shilling, whilst many thousand 

 pounds have been given for a single fine pearl of surpassing beauty. 



Other important pearl-fisheries besides that of Ceylon are carried 

 on in the Persian Gulf, on the west coast of Central America, and 

 especially North-west Australia, where diving-dresses are now 

 employed in collecting the shells. 



The Chinese obtain pearls artificially from a species of fvesh- 

 -w&tev Mussel {Dip sas pi icata). In order to do this they keep them 

 in tanks and insert between the shell and the animal either small 

 shot or small round pieces of mother-of-pearl, which soon receive 

 regular coatings of nacre and assume the look of ordinary pearls. 

 They also insert small metal images of Buddha, which also soon 

 become covered with pearl and firmly cemented to the shell, the 

 production being to the uninitiated a supernatural testimony to the 

 truth of Buddhism. (A shell treated in this way is exhibited in one 

 of the small cases (E) at the side of the room.) 



D 2 



