228 
Part III. — Eighth Annual Report 
greening and fattening of the oyster ; but on the nortli of the river Seudre, 
which separates La Tremblade from Marennes, and opposite He d'Oleron, 
the oyster can be fattened and still remain white. 
The chief point to be noticed is that the oysters are transferred to a 
locality rich in food, and fulfilling other conditions of nutrition — to pares 
d'elevage. 
The oysters which it is not desired to green are laid down either on the 
banks of mud, or on the gravel and rocks close to land. These are 
laid down in the sea directly, but others are transferred to pares, viviers et 
depots — reservoirs — which are in direct connection with the sea at all times ; 
but if it is sought to green the oysters, these are laid down in specially 
prepared claires, which are often some distance removed from the river 
Seudre, and have only connection with the sea at the times of 'springs.' 
The claires are the property of the proprietors of the neighbouring lands, 
and thus differ from the foreshore concessions or ordinary pares let by the 
Government. 
The greening claires are either high or low, situated according to their 
distance from the Seudre. They are bounded by banks of mud about a 
metre high, and they are provided with sluices to regulate the entrance 
and exit of water. Inside the bounding banks a ditch runs round the 
claire, and the bottom of the claire slopes from the centre downwards to- 
wards the ditch. Oysters which are placed in one of those specially prepared 
claires generally begin to green in about a fortnight, though some of them 
take longer. The labial palps, gills, and intestine become green-coloured 
from the presence of a diatom, Navicula ostrearia, and the green oysters 
are regarded by connoisseurs as special delicacies. While the greening is 
taking place the oyster fills up and fattens, becoming ready for the 
market in a comparatively short time. 
The claire has to be prepared every year, and there are two steps in 
the preparation. They are dug, and the ground is cleared and hardened 
by evaporation. After the draining and hardening of the rounded 
surface, the ground cracks, and the process of gralage is completed. This 
process occupies six or eight weeks, and is succeeded by the second step. 
A small quantity of water is introduced, and ultimately the bottom is 
covered by a white, creamy effervescence — humeur. This completed, the 
claire is ready to receive the oysters, which have to be greened and 
fattened. 
Oysters are received in March and April, and they are edible in 
September and October. The mortality is great, averaging about 20 per 
cent., but the proprietors, who buy oysters from the Morbihan and 
Arcachon at 15 to 25 francs per thousand, realise for them 30 to 90 francs, 
the average being from 40 to 50 francs per thousand. 
The ground in the Morbihan is not only too soft for the laying of the 
tiles upon, necessitating the placing them en bouquet to receive the spat, 
but in places it is even too soft to lay down oysters for fattening. Dr 
Gressy, to render this soft ground suitable for placing oysters upon it, 
mixed the mud with gravel, and so hardened or macadamised the ground 
of the pare, thus reclaiming it and making it suitable for oyster pares. 
Conclusion. 
It is exceedingly desirable that general information as to the best 
methods, or the methods which in other countries have yielded the best 
results, should be as widely made known as possible, especially among 
these meditating the starting of oyster culture on dilferent parts of the 
Scottish seaboard. There is a pretty widely diffused notion that some- 
