FISH AND FISHERIES. 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 
parc 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 14 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 (“crossets”) 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 
France; 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 spicule, 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 effect 
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 Cliona) 
ig in its anatomical details one of the simplest and smallest of sponges, being a 
mere thread. 
