[17] CONDITION OF OYSTER CULTURE IN 1875. 901 
They are especially employed upon bottoms consisting of soft mud. 
They consist of rude deal platforms, placed one above the other, at a 
certain elevation, and separated by interspaces whose height is equal to 
the cross-pieces serving as supports. In order to retain the structure 
in place and prevent its being carried away by the waves, it is either 
surrounded by a line of stakes or the upper platform is loaded with 
stones. The objection to this style of collector is, that the oysters do 
not adhere to it very firmly, but are easily detached and swept off by 
the currents. This defect is remedied by a coating of lime like that 
given to the tiles, for a very different purpose, however. On hard bot- 
toms the parkers of Morbihan prefer tiles arranged in hives, as at Ar- 
cachon. They also suspend the tiles from stakes by means of iron wire. 
The tiles are pierced by a single hole at each extremity, and through 
these holes an iron wire is passed so as to maintain the tiles in a nearly 
horizontal position. The ends of all the wires are then fastened to the 
top of the stake. By this means veritable quagmires can be utilized, 
which are otherwise unproductive and inaccessible to persons on foot. 
In Morbihan the collectors are not usually put in place until the begin- 
ning of July; but there, as elsewhere, it depends upon the temperature, 
and the prudent oyster culturist should, before proceeding, make certain 
that the mother oysters of the natural banks are about to spawn. The 
preservation of the spat is now the principal question in this region. 
Many claires are constructed for the reception of the young oysters, 
which are usually detached from the collectors at the age of nine months; 
but suitable grounds are not always within reach of the breeding-park, 
and amends are sometimes made for this by using boxes, whose four 
sides consist of wire netting. 
USAGES AT THE PARKS OF VIVIER. 
The collectors which have produced the best results on the shores of 
Vivier, near Cancale, are slabs of schist and birch screens. ‘The slates, 
although favorably regarded in the beginning, have been discarded on 
account of their expense, and for the reason that they cause the oysters 
to assume a flattened shape, which reduces their market value. The 
screens are divided into sections, from 5 to 6 meters (16 to 20 feet) long, 
to facilitate their removal and cleansing; they are fastened to stakes, 
5 centimeters (2 inches) in diameter and 66 centimeters (24 inches) 
high. Being arranged in the direction of the current, they form paraliel 
lines, stretching the entire length of the park, and at a distance of 4 or 
5 meters (13 {016 feet) apart. Between these rows are placed horizontal 
cross-pieces of wood, raised 20 centimeters (8 inches) above the bottom, 
on which are fastened slabs of schist, 50 centimeters (20 inches) long by 
25 (10 inches) wide, and 15 (6 inches) thick, supported one upon the 
other at their extremities. In some parks the stones are retained in a 
vertical position by means of stakes driven into the ground on both sides 
of them. The latter arrangement is more favorable for the collection. 
