A shell nearly related to the oyster produces the costly pearls of the East that have ever been as highly esteemed as the diamond itself. The most renowned pearl-fisheries are carried on at Bahrein, in the Persian Gulf, and in the Bay of Condatchy, in the island of Ceylon, on banks situated a few miles from the coast. Before the beginning of the fishery, the government causes the banks to be explored, and then lets them to the highest bidder, very wisely allowing only a part of them to be fished every year. The fishing begins in February, and ceases by the beginning of April. The boats employed for this purpose assemble in the bay, set off at night at the firing of a signal-gun, and reach the banks after sunrise, where fishing goes on till noon, when the sea-breeze which arises about that time warns them to return to the bay. As soon as they appear within sight, another gun is fired, to inform the anxious owners of their return. Each boat carries twenty men and a chief; ten of them row and hoist up the divers, who are let down by fives,—and thus alternately diving and resting keep their strength to the end of their day's work. The diver, when he is about to plunge, compresses his nostrils tightly with a small piece of horn, which keeps the water out, and stuffs his ears with bees'-wax for the same purpose. He then seizes with the toes of his right foot a rope to which a stone is attached, to accelerate the descent, while the other foot grasps a bag of network. With his right hand he lays hold of another rope, and in this manner rapidly reaches the bottom. He then hangs the net round his neck, and with much dexterity and all possible despatch collects as many oysters as he can while he is able to remain under water, which is usually about two minutes. He then resumes his former position, makes a signal to those above by pulling the rope in his right hand, and is immediately by this means hauled up into the boat, leaving the stone to be pulled up afterwards by the rope attached to it. Accustomed from infancy to their work, these divers do not fear descending repeatedly to depths of fifty or sixty feet. They plunge more than fifty times in a morning, and collect each time about a hundred shells. Sometimes, however, the exertion is so great that, upon being brought into the boat, they discharge blood from their mouth, ears, and nostrils.
Ceylon Pearl-Oyster.
While the fishing goes on, a number of conjurors and priests are assembled on the coast, busily employed in protecting the divers by their incantations against the voracity of the sharks. These are the great terror of the divers, but they have such confidence in the skill or power of their conjurors that they neglect every other means of defence. The divers are paid in money, or receive a part of the oyster-shells in payment. Often, indeed, they try to add to their gains by swallowing here or there a pearl, but the sly merchant knows how to find the stolen property. The oysters, when safely landed, are piled up on mats, in places fenced round for the purpose. As soon as the animals are dead, the pearls can easily be sought for and extracted from the gaping shells. After the harvest has been gathered, the largest, thickest, and finest shells, which furnish mother-of-pearl, are sorted, and the remaining heap is left to pollute the air. Some poor Indians, however, often remain for weeks on the spot, stirring the putrid mass in the hopes of gleaning some forgotten pearls from the heap of rottenness. The pearls are drilled and stringed in Ceylon, a work which is performed with admirable dexterity and quickness. For cleaning, rounding, and polishing them, a powder of ground pearls is made use of.
The Pacific also furnishes these costly ornaments to wealth and beauty, but the pearls of California and Tahiti are less prized than those of the Indian Ocean.
Pearl-like excrescences likewise form on the inner surface of our oysters and mussels, and originate in the same manner as the true pearls. The formation of the pearl, however, is not yet quite satisfactorily accounted for. Some naturalists believe that the animal accumulates the pearl-like substance to give the shell a greater thickness and solidity in the places where it has been perforated by some annelide or gasteropod; and according to Mr. Philippi, an intestinal worm stimulates the exudation of the pearl-like mass, which, on hardening, encloses and renders it harmless.
Brilliancy, size, and perfect regularity of form are the essential qualities of a beautiful pearl. Their union in a single specimen is rare, but it is of course still more difficult to find a number of pearls of equal size and beauty for a costly necklace or a princely tiara.
Nature has given the bivalves the same beauty of colouring and wonderful variety of elegant or capricious forms as to the sea-snails; so that they are equally esteemed in the cabinets of wealthy amateurs. Among the most costly are reckoned the Spondyli, which are found in the tropical seas, where they grow attached to rocks. They are distinguished by the brilliancy of their colours, but particularly by the long thorny excrescences with which their shells are covered. A Parisian professor once pawned all his silver spoons and forks to make up the sum of six thousand francs which was asked for a Royal Spondylus; but on returning home was so warmly received by his lady that, overwhelmed by the hurricane, he flung himself on a chair, when the terrific cracking of the box containing his treasure reminded him too late that he had concealed it in his skirt-pocket. Fortunately but two of the thorns had been broken off, and the damage was susceptible of being repaired; his despair, however, was so great that his wife had not the heart to continue her reproaches, and in her turn began to soothe the unfortunate collector.
Tridacna gigas.