490 THE PEARL FISHERTER OF CEYLON. 



sions given in my proliiuinarv report (July, 1002) to the governor 

 of Ceylon ran as follows : 



I. The oysters we met Avith seemed, on the whole, to be very 

 healthy. 



'2. There is no evidence of any epidemic or of nuich disease of any 

 kind. 



'^. A considei'ahle numher of i:)arasites, both extei-nal and internal, 

 both Protozoan and ^"ermean, were met with, but that is not uuusual 

 in molluaks, and we do not regard it as atfecting seriously tiie oyster 

 population. 



4. Many of the larger oysters were reproducing actively. 



5. We fouud large (juantities of minute " s})at " in several places. 

 G. We also found enoi'iiions quantities of young oysters a few 



months old on many of the ]>aars. On the Periya Paar the number 

 of these probably amounted to over 100,000 million. 



7. A very large number of these young oystei's never arrive at; 

 maturity. There are several causes for this. 



8. They have many natural enemies, some of which we have deter- 

 mined. 



9. Some are smothered in sand. 



10. Some grounds are nnich more suitable than others for feeding 

 the 3'oung oysters, and so couducive to life and gi'owth. 



II. Probably the majorit}' are killed by overcrowding. 



12. They should therefore be thinned out and transplanted. 



13. This can l)e easily and speedily done, on a large scale, by 

 dredging from a steamer, at the proper time of year, when the young 

 oysters are at the best age for transplanting. 



14. Finally, there is no reason for any despondency in regard to 

 the future of the pearl oystei- fisheries, if they are treated scientific- 

 ally. The adult oysters are plentiful on some of the paars and seem 

 for the most part healthy and vigoi'ous, while young oysters in their 

 first year, and masses of minute spat just deposited, are vei-y abun- 

 dant in many places. 



To the biologist two dangers are, hoAvever, evident, and, paradox- 

 ical as it may seem, these ai'e overcroAvding and oA'erfishing. Put the 

 superabundance and the rislv of depletion are at the opposite ends Oi 

 the life cycle, and therefore both are possible at once on the same 

 ground — and either is sufficient to cause locally and teni})orarily a 

 failure of the pearl oyster fishery. What is required to obviate these 

 two dangers ahead and insure more constancy in the fisheries, is 

 careful supervision of the banks by some one Avho has had sufficient 

 biological training to understand the life problems of the animal, 

 and Avho Avill therefore kuQAV Avhen to carr\' out sim])le measures oi: 

 farming, such as thinning and transplanting, and Avhen to advise as 

 to the regulation of the fisheries. 



