REPOPULATION 145 



sluice ; it is known as the borgnon, and is a kind of 

 dome or cone of osier. As the aperture in which the 

 borgnon is fixed is always open, the waters of the fish- 

 pond escape at low tide in a little cascade. The Arcachon 

 ponds are of the "closed" type, and those of the Vendee of 

 the "open" type. The same species of fish are found, with 

 a few soles, and sometimes turbot. Despite the cold and 

 the wind, powerful enemies of these fish, an acre of water, 

 according to M. Linyer, will furnish annually 132 Ibs. of 

 mullet and bar, 35 Ibs. of eels, and 88 Ibs. of inferior species. 

 In the Mediterranean the almost imperceptible tidal 

 currents have to be supplemented by artificial means. 

 Small watercourses are for this purpose diverted into 

 the seaside lakes. It is indispensable, however, that the 

 stream should give a constant current. As this condition 

 is not often realised, and as the salt-marshes are profit- 

 able, there are practically no fishponds now in existence. 1 

 However, in 1864 M. Paul Vidal dug some basins at 

 Port-de-Bouc, along the canal of La Molle. Each basin 

 had an area of 28 to 34 square yards, and its average 

 depth was 4 feet 10 inches. The "deeps" were 13 to 

 1 6 feet deep ; the shallowest of the " shallows " were 

 covered by only 8 inches of water. M. Vidal filled his 

 fishponds with eels, mullet, and bar. He fed the eel-fry 

 on small living fish, crushed crabs, earthworms and 

 slugs ; the mullet fry with sea-weeds, crushed mussels, 

 and dead fish ; the bar fry with crabs, shrimps, and 

 gobies. 2 Placing in a fishpond 100 feet square 700 



1 There used to be one at La Peyrade, near Cette, but I do not 

 know if it still exists. 



* Food is not distributed continually. But M. Fabre-Domergue 

 thinks that in such cases the fish eat one another, and that an 

 abundant artificial diet would increase the yield. Perhaps : but at 

 what an expense ! 



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