282 Professor W. A. Herdman [March 27, 



Mar. 1893. Abundance of oysters of 6 months old. 



Mar. 1894. No oysters on the bank. 



IMar. 1895. Ditto. 



Mar. 1896. Abundance of young oysters, 3 to 6 montlis. 



Mar. 1897. No oysters present. 



Mar. 1898. Ditto. 



Mar. 1899. Abundance of oysters, 3 to 6 months old. 



Mar. 1900. Abundance of oysters 3 to 6 months old ; none of last year's 



remaining. 

 Mar. 1901. Oysters present of 12 to 18 months of age, but not so numerous 



as in preceding year. 

 Mar, 1902. Young oysters abundant, 2 to 3 months. Only a few small 



patches of older oysters (2 to 2^ years) remaining. 

 Nov. 1902. All the oysters gone. 



It is shown by the above that since 1880 the bank has been 

 naturally re-stocked with young oysters at least eleven times without 

 yielding a fishery. 



The 10-fathom line skirts the western edge of the paar, and the 

 100-fathom line is not far outside it. An examination of the great 

 slope outside is sufficient to show that the south-west monsoon 

 running up towards the Bay of Bengal for six months in the year, 

 must batter with full force on the exposed seaward edge of the bank 

 and cause great disturbance of the bottom. We made a careful 

 survey of the Periya Paar in March 1902, and found it covered with 

 young oysters a few months old. In my preliminary report to the 

 Government written in July, I estimated these young oysters at not 

 less than a hundred thousand millions, and stated my belief that 

 these were doomed to destruction, and ought to be removed at the 

 earliest opportunity to a safer locality further inshore. Mr. Hornell 

 was authorised by the Governor of Ceylon to carry out this recom- 

 mendation, and went to the Periya Paar early in November with 

 boats and appliances suitable for the work ; but found he had arrived 

 too late. The south-west monsoon had intervened, the l)ed had 

 apparently been swept clean, and the enormous population of young 

 oysters, which we had seen in March, and which might have been 

 used to stock many of the smaller inshore paars, was now in all 

 probability either buried in sand or carried down the steep declivity 

 into the deep water outside. This experience, taken along with what 

 we know of the past history of the bank as revealed by the inspectors' 

 reports, shows that whenever young oysters are found on the Periya 

 Paar, they ought, without delay, to be dredged up in bulk and 

 transplanted to suitable ground in the Cheval district — the region 

 where the most reliable paars are placed. 



From this example of the Periya Paar it is clear that in consider- 

 ing the vicissitudes of the pearl oyster banks, we have to deal with 

 great natural causes which cannot be removed, but which may to 

 some extent be avoided, and that consequently, it is necessary to 

 introduce large measures of cultivation and regulation in order to 

 increase the adult population on tlic grounds, give greater constancy 



