OYSTER CULTURE IN FRANCE. 547 



The collectors employed by M. de Thevenard differ 

 according to the nature of the soil. On muddy grounds 

 they are composed of a cluster of ten tiles crossed, one 

 above the other, two and two, suspended on a stake two 

 metres high. A platform nailed 30 centimetres below the 

 tiles prevents the apparatus from sinking in the mud. This 

 extremely ingenious plan, which allows of placing collec- 

 tors on all the muddy bottoms of the rivers in Morbihan, 

 was invented by M. Eugene Le Roux, and M. Thevenard 

 has perfected it by adding a second platform above the 

 first. 



On more solid grounds the usual hives are used, or 

 else tiles are merely placed one above the other on cross- 

 pieces of wood, sometimes also boards are made use of as 

 collectors. The collectors are plastered over before their 

 .immersion. This operation is effected in the following 

 manner : According to the method of M. Martin, of the 

 River Crach, \vhich M. de Thevenard has adopted, some 

 mud, to which a tenth part of hydraulic lime has been added, 



9 



is diluted in a large tub of sea-water. It is necessary that 

 this mixture should be sufficiently liquid for it to spread 

 and adhere easily everywhere. The collectors are then 

 plunged into these baths. Three or four hours after, and 

 before this layer is quite dry, the apparatus is again soaked 

 in another tub, in which there is only hydraulic lime and 

 sea-water. 



The collectors are put in their places at the commence- 

 ment of June, the time when the emission of the spat com- 

 mences, which is sometimes prolonged until the month of 

 August, and even a little later in the River of Bono ; they 

 are taken out, for picking off, at the beginning of winter. 



M. de Thevenard conducts this operation by means of 

 a barge, on which is fixed a lever, one of the extremities of 



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