134 PEARLS [CH. 



oysters, by artificial "culching," that is to say, 

 scattering dead coral, rocks or rubble on the sandy 

 bottom adjoining the more important paars. 



The following agents were recognised as causing 

 widespread death of the pearl oysters : 



1. Shifting sand, due to strong currents ; 



2. Voracious fishes, chiefly rays and file fishes; 



3. Invertebrate animals, such as boring shellfish, 



boring sponges, starfishes and the smother- 

 ing mollusc, Modiola. 



At the time of this scientific investigation, it was 

 seen that certain banks were covered with pearl 

 oysters and there was a prospect, if all went well, 

 of a fishery in 1903. This fishery came ofi* and was 

 the first for 12 years. The revenue netted by the 

 Government was over £55,000 



The following years, 1904 and 1905, were still 

 greater successes and record fisheries took place, 

 giving £71,150 and over £167,000 respectively. 



Such was the position, Avhen in 1906 a company 

 was formed and the Ceylon pearl fisheries were 

 leased for a period of 20 years at an annual 

 rental of Rs. 310,000. In addition to this, however, 

 the company had to undertake to spend from 

 Rs. 50,000 to Rs. 150,000 annually "on the experi- 

 mental or practical culture of the pearl oyster and 

 on the improvement of the pearl banks within the 

 conceded area, and the maintenance thereon of a 



