118 CEYLON PEAEL OYSTER REPORT. 



We do not mean to assert that the oysters have a power of locomotion that would 

 enable them to migrate to any great distance ; but our observations have convinced 

 us that they have powers of freeing themselves from sand, of moving to a better 

 position, of re-attaching themselves when torn off from their moorings, and of 

 repairing injuries to shell and mantle (for details see section ' Observations and 

 Experiments,' &c, Part I., p. 125), with which they are not usually credited.* All 

 these field and laboratory observations, it is scarcely necessary to point out, have an 

 important bearing upon some of the practical recommendations that follow (p. 133). 



IV. Practical Considerations. 



Many of our observations and experiments were made with the view of gaining 

 information as to the practicability of transplanting the pearl oysters from one locality 

 to another. We have shown that the transportation of oysters, both old and young, 

 even for considerable distances such as from the head of the Gulf of Manaar to Galle, 

 a matter of four or five days at the hottest season of the year, is comparatively easy if 

 ordinary precautions be taken to keep the water in the vessels as cool as possible and to 

 prevent any decomposition taking place. Transplanted specimens, moreover, flourished 

 in our hands. Both at Galle and in the Gulf of Manaar (where some batches were 

 moved from the Muttuvaratu Paar to the Cheval) the oysters improved in health and 

 grew rapidly in size when moved to a new locality. We have given the details of 

 growth for both old and young oysters in preceding sections of this Report (see 

 Part I., p. 136). These and other experiments were all undertaken because of their 

 beaiing upon that transplantation, in quantity, from overcrowded and unreliable 

 paars to more suitable ground, which we have advocated throughout this Report. 



Some of our experiments gave us a clear indication, which, however, we also 

 obtained from observations on the pearl banks, of the kinds of foreign objects best 

 suited for young pearl oysters to settle down upon, and also of the objects, such as 

 living coral, to which they cannot become attached. This, then, led lis to recognise 

 the value of natural " cultch," or suitable hard objects, such as dead coral fragments, 

 old shells and nullipores, upon the bottom, and the importance of increasing the 

 area available for beds by the artificial "cultching" of the more sandy parts of the 

 paar-ground. 



We must not try to be too precise in regard to the positions, sizes and outlines of 

 the paars. Our work in the "Lady Havelock" showed us that some spots around 

 and between them are more or less hard-bottomed, and even, in some cases, bear 

 oysters, and are evidently capable of becoming fishable paars. On the other hand, it 

 is clear from the record of the inspections that many parts of the known paars may be 



* Although Kelaart observed certain powers of locomotion and of byssus regeneration nearly fifty 

 years ago; and more recently H. Suj.lvan Thomas (1884) made similar observations. 



