Royal Physical Society. 405 



of the same means, succeeded in producing pearls in the edible 

 mussel or oyster of England. It may therefore be hoped that 

 I shall eventually succeed with the pearl oyster of Ceylon. All 

 that I can at present say is, that they do not die under the oper- 

 ation, and that they are still living, having also re-formed new 

 byssuses. This is the only way the period required for the 

 formation of good sized pearls can be ascertained. There are 

 some other points in the natural habits of the pearl oyster 

 which I reserve for future Reports, as precipitate conclusions 

 may mislead the Government. 



Through the kindness of Patrick Dalmahoy, Esq., W.S., specimens of 

 the Meleagrina margaritifera were exhibited ; and also the large fresh- 

 water mussel of this country, Unio margaritiferus, in which our native 

 pearls are chiefly found, as well as several fine specimens of Scottish pearls 

 from Argyle shire. 



One of the members of the Society having stated that, according to 

 fishermen, the common mussel could not refix itself after having been re- 

 moved from its attachment, Dr Strethill Wright said that such an opinion 

 was incorrect, the mussel could cast off its byssus and renew it at pleasure, 

 moving from place to place in the meantime. The threads of the byssus 

 were moulded in the groove of the foot. He stated, in reference to the 

 pearl oyster living in brackish water, that the common oyster thrives in 

 fresh water, and thought it not impossible that it might be kept in this 

 way, and fed for economic purposes. 



II. Exhibition of Lignite from the Ballarat Gold-Field, and of some 

 specimens of recent Woods from Australia. By William Oliphant, 

 Esq. 



Mr Oliphant stated that some time since he had received 

 from John L. Currie, Esq., Lara, Victoria, several specimens 

 of lignite or bituminous wood, which possessed considerable 

 interest. They had been procured on a visit to the Ballarat 

 gold-field, which is situated about 75 miles from Melbourne, 

 in a deep sinking, from a stratum at about 170 feet from the 

 present surface. This stratum was several feet in thickness, 

 and contained many large and apparently nearly perfect trunks 

 of trees, which must be the remains of a dense and extensive 

 forest. The lignite overlies the deposit in which the gold is 

 found, and may possibly serve as an index to the position of 

 gold in other localities. The lignites exhibited are of a gray- 



