riSH AND FISHEEIES. 119 



Auray in Brittany is, next to Arcachon, the seat of the most 

 important of all French oyster fisheries. There is one establishment in 

 the Auray district which comprises about 100 acres in a single enclosure 

 and about 12 hectares between the enclosure and the sea. In 1864 the 

 sea broke in and submerged it, causing as it was thought great destruc- 

 tion ; but the proprietor took advantage of the accident to form the 

 pare into an oyster tank by means of substantial and costly embank- 

 ments. In 1876 the owner laid down six million oysters, more than 

 half of which were about 1^- inch long. All have grown well, and so 

 satisfactory have been the results that contracts were entered into for 

 the supply of a million of oysters to Paris, and the same to London, and 

 the quantity is now probably doubled to each place. 



In this Colony we have plenty of salt-water swamps, marshes, mud- 

 banks (" cressets") more or less covered by the tides, where the fattening 

 of oysters, or "greening" them, could be carried on. We have the 

 same kind of rich mud as the estuary of the Thames, which is so 

 celebrated for fattening oysters. Analyses made of the mud from one 

 of the bays of George's River showed it to be similar to the London 

 clay out of which Portland cement is made. Our unsightly and 

 unhealthy waste marshes might then be made a great source of wealth. 

 The " claires" need not be of any particular shape or size. Oysters 

 grow best in shallow water. A fattening ground is usually a small 

 creek with muddy banks, and the bed is made in the middle with shells 

 on which the oysters are laid. Mr. Holt (Chairman of the Oyster 

 Commission) constructed many claires on the coasts of New South 

 Wales, more than 30 miles in total length, but his experience was 

 decidedly against damming them. At first he made many flood-gates 

 and dams, according to the most approved systems he had seen in 

 Prance ; but he has since done away with them entirely, and let the 

 oysters have the full benefit of the ebb and flow of the tide. This has 

 been a great saving in the expense, and the oysters have done better. 

 It should, however, be mentioned the ebb and flow is much smaller 

 here than on the coasts of France, and with consequently less danger of 

 the stock being carried away. 



Oysters have many enemies, one of the commonest of which is the 

 sponge {Hymeniacidon celata*), which forms for itself branching cavities 

 by its siliceous spiculje, and completely honeycombs the shell. It is thus 

 easily crushed, and the animal becomes exposed and dies. It is said 

 that exposing the shell to the sunshine is a remedy to this, and in efiect 

 the rock oyster, which is often long uncovered by the tide, does not 

 seem to be much attacked by this parasite. 



" Ten or twelve years ago the oyster industry in France was in a high 

 state of prosperity, but five or six years later it was in a most deplorable 

 state, and Mr. Pennell and others gave melancholy accounts of the 

 failures of oyster culture in that country. This did not arise from 

 natural causes, such as frost, snow, floods, &c., which occasioned such 



* This was the old opinion, and is quoted by Buckland. Dr. Bowerbank contends 

 that the mischief is done by an annelid worm which leaves borings which the 

 sponge afterwards inhabits. H. celata, Bk. (which Buckland refers to as C'liona) 

 is in its anatomical details one of the simplest and smallest of sponges, being a 

 mere thread. 



