[11] OYSTER CULTURE IN FRANCE. 735 



It is also impossible not to perceive how the trade in Portuguese oys- 

 ters has developed. Of the 151,000,000 of oysters sold this year 54,- 

 000,000 were Portuguese. 



I must now pause for an instant to dwell on the care bestowed by the 

 cultivators of this district on their claires. i!^ot that I desire now to 

 bring forward facts already well known, but because I conceive that the 

 administration of the claires of Marennes might be imitated with ad- 

 vantage in other centers of oyster cultivation. 



The claires are placed on both banks of the Seudre; they are not, as 

 at Arcachon, submerged at each tide, but only at spring tide. Some 

 are even a long way from the banks of the river. They are so worked 

 that some are in a state of preparation whilst others are in use. 



The preparation of the ground generally goes on in March. It in- 

 cludes two operations: gralage and la mise en humeur. 



Gralage has for its object the purification of the soil by evaporation; 

 it lasts from six weeks to two months. The claires are cutj that is, the 

 water is no longer kept in them, and they are not visited by tlie sea 

 except at high tides. They dry in the sun. When the claire is gralee^ 

 or, in other words, covered with a well drained bed, 15 days are spent 

 in bringing it into condition. A small quantity of water is allowed to 

 enter, and the retention is resumed. 



The dry crust dissolves in the water, produces a kind of effervescence, 

 and the final result i. a uniform deposit on the claire of a creamy precipi- 

 tate, which is called humeur. The oysters may now be laid down, and 

 thej' begin to turn green at the end of a fortnight. 



This operation must be conducted every year. The oysters are laid 

 down at the bottom of the elaire, and placed at a proper distance from 

 each other by hand. About 5,000 are placed in an area of 33 acres. 



Down to the present time the industry of Marennes has been con- 

 fined to rearing and fattening. It is to be hoped that before long pro- 

 duction will be introduced into this locality. The commissary of marine 

 of this quarter is indeed actually engaged on this question. 



Having resided for a long time at Auray, Bt. Senn^-Desj^rdins is 

 conversant with every question pertaining to oyster-cultivation. His 

 intelligence and the devotion he displays in all his duties allow of the 

 hope that this new enterprise will be a success. On many other points 

 of our seashore the rearing of oysters engages attention. 



1 do ijot consider it desirable to pass in review all the localities where 

 the industry is exercised, but I will speak a few words respecting one 

 of these centers which, I think, possesses special interest. 



1 wish to speak of the pares established some time since at CourseuUes. 

 They are situated in the vicinity of the Senile, a small river which runs 

 into the sea at this point of our Norman coast. 



The canals which communicate with the sea and the oyster basins 

 are so disposed that when the sea rises it cannot, during neap tide, get 

 beyond the sluice gates 5 consequently, during that period the sea water 



