Oct.— dec. 1857.] The Pearl Oyster of Ceylon. 



103 



have seen the vestiges, or cicatrices, in the mantle where the 

 Pearls once existed. Though Pearls originate in the mantle, 

 when large they work their way out, and lie loose between it and 

 the shell ; or become attached to the " Mother-o'-Pearl" surface 

 of the latter. I have no doubt that Pearls can work their way 

 out from this position, and be found entangled in the meshes of 

 the byssus. I also consider it very possible, that an over-distended 

 ovarium is one of the causes of Pearls being discharged from the 

 Oyster and lost. If this be really the case, it will easily account 

 for the singular fact, that a sample of Oysters, fished in the month 

 of October, will yield a larger proportion of Pearls, than a batch of 

 Oysters fished from the same bank in the months of April and May 

 of the following year. These observations are somewhat sugges- 

 tive, and can be improved upon by future investigation. 



I have now drawn to a conclusion this Report, which, I fear, 

 has extended to a greater length than will suit the patience of the 

 reader. Eut the subject being one which has been so long neg- 

 lected and so little understood, I hope that the Government which 

 has engaged my services, if they do not consider my endeavours as 

 already productive of some practical results, will, at least, see in 

 these researches, glimpses of future success. It is due to Sir Henry 

 Ward, here to acknowledge my grateful thanks, in which my bro- 

 ther Naturalists in all parts of the world, I am sure, will join for 

 the gracious manner in which my humble services have been re- 

 tained, for investigating, fundamentally and practically, the Natural 

 History of a species of Shell, which from the darkest ages of the 

 world to the present, has been considered of inestimable value in 

 producing one of the richest of gems. Time was, when the product 

 of Pearl Oyster fisheries founded cities in South America and the 

 Red Sea. Rut what is the state of the Islands in the Red Sea, 

 " whose merchants were princes" ? They are now thinly inhabit- 

 ed by a miserable race of fishermen. The sites of some of the Oys- 

 ter banks in South America are not even now known ; they have 

 been destroyed by being overfished. New beds are doubtless form- 

 ing in localities to be yet known to future generations. Ceylon 

 Pearl banks were once on the point of sinking into the same state, 

 but for the subsequent observance of more caution, I was present 



