 1883.] Pearls and Pearl Fisheries. 733 
pearl. The second species is much larger and thicker; nearly 
flat, and produces the most valuable pearl-shell as well as good 
pearls.. Both species, with several local varieties, are somewhat 
widely spread- over the Indian, Australian and Indo-Pacific seas. 
The beds and banks are annually surveyed to ascertain their con- 
dition. They are situated about twelve miles west of Ceylon, and 
extend some ninety miles parallel with the coast, consisting of 
calcareous or coral rocks covered with eighteen to forty feet of 
water, 
The numerous changes which have taken place in the mode of 
letting and regulating the fisheries, have rendered it difficult to 
give a thoroughly accurate account of their present status. Most 
books of reference, such as the Encyclopædia Britannica and the 
descriptions of such authors as Frédé, are compiled from other 
accounts of different dates, and are therefore inaccurate and con- 
fused. 
It has been the policy of the authorities in Ceylon to divide the 
beds and to allow only one fourth of them to be fished annually, 
thus giving each bed four years’ rest. In earlier times seven years 
was allowed. But the objection to the system is, that, owing to 
the numerous enemies to whose attacks the shell fish are subject 
(and other causes), banks of oysters have been known to disappear 
almost totally within a single year when left unfished for more - 
than three or four years. So while the temptation is very great 
to leave the beds untouched for a long period, in hope of securing 
a supply of large pearls, the danger that the whole may be lost, 
More than counterbalances it. The government is therefore pro- 
ceeding experimentally to determine the most suitable length for 
. the period of rest. Experimental divings made from 1875-8 
showed that the banks then being fished contained some ten mil- 
lions oysters. The average number of pearls to be expected is 
about two in one hundred oysters. The value per thousand of 
the oysters depends upon the size of the pearls. The theory is, 
that pearl-oysters in the last year of their existence double their 
Value all round. If a thousand oysters produce pearls altogether 
Worth $100, the catch is considered very good. One hundred as 
ig asa pin’s head are not worth one as big as a pea, so that the 
fishery is practically a lottery with a few prizes and millions of 
blanks. To give all an equal chance, the boats are selected by 
Tot, sent out by turns in fleets of about fifty, each fleet in succes- 
