The question arises, What _are_ pearls? Are they a morbid concretion of matter produced in the endeavour to heal a wound or to cover some irritating body that cannot easily be ejected from the shells? Are they the result of a disease, or are they simply an over-production of the matter forming the shell of the creature? Whatever they are, it is only in the adult oyster that they are found of any size. The rate of growth in the size of a pearl cannot of course be actually ascertained; but by a series of averages, taken from the produce of a large number of oysters from the same bed in different years, it is proved that after the fourth year, the yield of pearls both in quantity and quality rapidly increases. It is in the hope of a bed of oysters which produces say five hundred rupees’ (L.50) worth of pearls per thousand oysters one year, so improving as to yield double that value next year, that many a fine bank has been left to perish from the causes referred to above, as well as from the attacks of enemies or sickness.
The whelk has lately been discovered to be a serious enemy to the pearl-oyster, just as it to the edible oyster of commerce; and a curious disease occasionally manifests itself among the inhabitants of the banks. The fatty portion of the animal, under which pearls are usually found, and which is usually of a pale cream colour, assumes a yellow tint, denoting sickness of some sort, the exact nature of which has not yet been ascertained.
Pearl-fishing is at the best only a gigantic lottery, the prizes in which bear a very small proportion to the blanks. But in this as in many other uncertain pursuits, hope always tells a flattering tale, and keeps awake the energies of thousands of interested operators. First there are the divers, who perform the actual operations of fishing for pearls. Arrayed in Nature’s garb, and provided with a knife and a small bag of netting in which to collect the gathered oysters, and with a rope tied round their waists, and a heavy stone attached to their feet, they are let down into the water, taking first a deep breath, and remaining there till forced to rise again. Expert divers will remain beneath the water for sixty, ninety, and even a hundred and eighty seconds. This period they occupy in detaching the mussels from the rocks, a matter frequently of much difficulty. Those of very small size they do not attempt to gather, for, as we have shewn, the larger the shells the more chance of their containing a pearl. The native divers are able to guess at the age of the oyster by the resistance it offers; and, as explained above, the older the oyster the more easily it is detached, and the greater the chance of its producing a large pearl.