106 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



nisliiiig- to commerce great quantities of oysters from other parts of 

 France, -whicli are brought here to be raised and fattened. 



The following figures, which I owe to the courtesy of M. Senne-Desjar- 

 dins, show the importan(;e of tlie Marennes trade for the years 1880-'81. 



The number of oysters introduced at Miirennes was one hundred and 

 ninety million, of which one hundred aiul thirty million were placed iu 

 the live-boxes and depots, and sixty million were placed in the claires. 

 Of the one hundred and thirty million in the rivers about forty million 

 were Portuguese, and about ninety million French. The exportation of 

 oysters from this place amounted to one hundred and fifty-one million. 

 Of this number fifty-four n)illion Portuguese and forty-seven million 

 French came from the depots and rivers, and fifty million came from 

 the claires. 



So, then, Marennes has sent off this year one hundred and fifty-one 

 million oysters, representing a value of 5,900,000 francs [$1,138,700]. 

 For the reasons which I have already indicated, these figures should 

 be increased rather than diminished. Marenues, outside of the oysters 

 raised in its claires, has an important trade iu the.se moUusks. Of the 

 one hundred and ninety million imported in 1880-'81, only sixty million 

 entered the claires. It is also iuipossible not to remark how much de- 

 velopment the Portuguese oyster business has taken. The one hun- 

 dred and fifty-one million oysters sold this year are estimated to include 

 fifty-four million of the Portuguese species. 



I must now dwell for an iu^tant on the care taken of their claires by 

 the oyster-culturists of this region. Not that I wish to repeat facts 

 here Avhich have been known for a long time, but because it appears to 

 me that the management of the claires of Marenues could be imitated 

 with advantage in other oyster-cultural centers. 



The claires are located on the two banks of the Seudre. They are not, 

 like those of Arcachon, submerged at every tide, but only at the height of 

 the si)ring tides. Some are even quite a distance from the rivei banks. 

 They are parceled out iu sucli a manner that some are being prepared 

 while the others are in operation. The preparation of the ground takes 

 place generally in the month of March. It comprehends two operations, 

 gralage and moistening. The gralagc has for its object the purification 

 of the soil by evaporation ; it lasts about six weeks or two months. The 

 claires are cut, that is to say, the retention of water is prevented, and 

 they are no more visited by the sea except at the spring tides. They 

 dry up iu the sun, crack, and grale. When the claire is graled, in other 

 words, covered with a very dry layer, fifteen da.ys are spent in moisten- 

 ing it. A small quantity of water is caused to enter and remain. The 

 dry crust splits [sedelife — breaks in the grain) in the water; it produces 

 a sort of effervescence, and the final result is a uniform deposit on the 

 claire of a creamy layer called humor. The oysters can then be put in 

 place, and commence to become green at the end of a fortnight. This 

 operation should be gone through every year. The oysters are placed 



