NO. 51.— 1900.] PEARL FISHERIES. 



181 



been lifted for a sample of pearls for the fishery of the 

 following years were sent to the Crown Agents to dispose of, 

 in communication with Messrs. Brooks & Faith, but subse- 

 quently they reported that the shells were of no value. 



However, the Gulf of Mannar pearl oyster shell must now 

 be of some value, as during the recent fisheries men were 

 sent by mercantile firms in Colombo to collect shells for 

 shipment to Europe. 



Migration of Oysters and Employment of Divers with 

 Diving Dress. 



It has frequently been surmised when oysters were reported 

 to have disappeared from a bed and no traces left of them, 

 that they had probably migrated to some other more suitable 

 locality, into depths beyond the capacity of native divers to 

 reach ; and that the employment of European divers with 

 diving dress might be the means of tracing them or of 

 finding new beds of oysters. 



My experience of pearl oysters is that they only move 

 about in their young stage, say up to one year old, and after 

 that age they remain on the bed they settle down upon, if a 

 rocky bed, until they come to ripe old age, unless they are 

 forcibly removed ; but if they happen to come on a sandy 

 bed, they would have no means of holding on, and would 

 most probably be drifted away and destroyed. 



I am led to this conclusion by observing that it is only 

 during their young stage that I find, when at anchor on a 

 bed of oysters, that they attach themselves to the vessel's 

 cable. The fact of the oysters mooring themselves by such 

 a strong cable as they do would also bear out this conclusion, 

 for if they were in the habit of moving about always it 

 would be unnatural for them to moor with many threads of 

 their byssus, when one or two threads would be sufficient 

 for a temporary resting-place. But, supposing they were in 

 the habit of migrating and got into depths beyond the 

 capacity of the native diver, say 10 fathoms as his greatest 

 working depth, the configuration of the bed of the ocean in 



