THE PEAEL FISHERIES. 67 



The pearl oyster (Meleagrina mar gar it if era) is the most valuable and interesting of 

 all the nacre (mother-of-pearl) bearing shells. The shell is nearly round, and greenish in 

 colour on the outside ; it furnishes at once the finest pearls, under favourable circum- 

 stances, and the nacre so useful in many industrial arts. Fine pearl and nacre have, 

 in short, the same origin. The nacre invests the whole interior of the shell, being the 

 same secretion which, in the pearl, has assumed the globular form; in one state it is 

 deposited as nacre on the walls of the bivalve, in the other as a pearl in the fleshy 

 interior of the animal. Between nacre and pearls, therefore, there is only the difference 

 of the form of the deposition. The finest pearls "solidified drops of dew/' as the 

 Orientals poetically term them are secretions of nacrous material spread over foreign 

 bodies which have accidentally got beneath the mantle of the mollusc. The animal, 

 if irritated by the intrusion of only a grain of sand, and being unable to remove it, 

 covers it with a natural secretion, and the pearl gradually grows in size. Almost 

 invariably some foreign body is found in their centre, if broken, which has served as 

 a nucleus to this concretion, the body being, perhaps, a sterile egg of the mollusc, 

 the egg of a fish, or a grain of sand, round which has been deposited in concentric 

 layers the beautiful and much prized gem. 



The Chinese and other Eastern nations turn this fact in the natural history of 

 this bivalve to practical use in making pearls and cameos. By introducing into the mantle 

 of the mollusc, or into the interior of its body, a round grain of sand, glass, or metal, 

 they induce a deposit which in time yields a pearl, in the one case free, and in the other 

 adhering to the shell. 



Pearls are sometimes produced in whole chaplets by the insertion of grains of quartz 

 connected by a string into the mantle of a species of Meleagrina ; in other cases, a dozen 

 enamelled figures of Buddha seated have been produced by inserting small plates of 

 embossed metal in the valves of the same species. The pearls are very naturally 

 small at first, but increase by the annual layers deposited on the original nucleus, their 

 brilliancy and shade of colour varying with that of the nacre from which they are pro- 

 duced. Sometimes they are diaphanous, silky, lustrous, and more or less iridescent; 

 occasionally they turn out dull, obscure, and even smoky. 



The pearl oyster is met with in very different latitudes. They are found in the 

 Persian Gulf, on the Arabian coast, and in Japan, in the American seas, and in the 

 islands of the South Sea; but the most important fisheries are found in the Bay of 

 Bengal, Ceylon, and other parts of the Indian Ocean. The Ceylon fisheries are 

 under Government inspection, and each year, before the fisheries commence, an official 

 inspection of the coast takes place. Sometimes the fishing is undertaken on account of 

 the State, at other times it is let to parties of speculators. In 1804 the pearl fishery 

 was granted to a capitalist for 120,000 ; but, to avoid impoverishing all the beds at 

 once, the same part of the gulf is not fished every year ; and, indeed, sometimes 

 the oysters disappoint the scientists and practical finders by migrating. 



The great fishery for mother- o'-pearl takes place in the Gulf of Manaar, a large 

 bay to the north-east of Ceylon. It occupies 250 boats, which come from different 

 parts of the coast ; they reach the ground at daybreak, the time being indicated by 



