Kechil beach. Many people believe that they come to better perfection if kept in sea water. I have reared mine in closed boxes, with Pulot rice strewn losely around them and the whole covered with a layer of cotton silk, though Mr. L. J. Scheerder has successfully reared some in fresh water. I am not able to say what is the average percentage of these pearl-producing shells, but out of 15 or 20 I picked up at Tanah Merah I only came across one. Mr. P. Marcus tells me he has extracted them from all descriptions of bivalve shells, the larger the shells the larger being the pearls. In one case he took a very large one from the Tridacna gigas, or giant clam, (of which a specimen may be seen at the foot of the stairs leading to the Raffles Library.)
The pearls when discovered are usually found embedded close to the valves of the shell, though in some cases found adhering to the fish. There appears to be no certainty as to size, the breeding pearls varying like the ordinary ones, though the rule as to the largest being contained in the largest shells does not in the latter case hold good. They are almost invariably spherical when found, but, when commencing to breed, change their shape to a more or less irregular oval, with layers of scales on them visible to the naked eye. In some cases the scales are them- selves spherical.
As regards the time occupied in "breeding," Mr. Woodford names a very much longer period than that specified by the other correspondents who have so kindly answered my enquiries. He states that it usually takes eight years for a seed pearl to into four times its original diameter, i. e. about 1/6 th of an inch, though he has seen one over 1/4 inch in measurement produced in that period.
After a certain time (which appears to be uncertain) "breeding pearls" die and change their lustrous colour to a dirty flake white, the outer scales appearing to have peeled off. Mr. Woodford attributes their formation to insects, though this otherwise feasible theory is at variance with all received beliefs as to the formation of the pearl within the oyster.
Several other residents have informed me that they have seen breeding pearls and their young (if the term be admissible) under circumstances which left no doubt as to the bona fides of their exhibitors. I have however doubtless given names enough to help us to a dispassionate discussion of this curious freak of nature.
