IN THE UNITED KINGDOM AND FRANCE. 19 



Unfortunately, however, this most promising experiment was 

 frustrated by severe storms which covered the bottom of the bay 

 with sand so as to completely bury the fascines. 



M. Coste's next operation was at Arcachon, on the Bay of 

 Biscay — a landlocked basin of 100 kilometres circumference, and 

 containing 1,500 square kilometres in area, equal to about 30,000 

 English acres. See plate 3, Appendix. 



Many years ago a very important oyster fishery had existed 

 there, yielding annually nearly 80,000,000 of oysters, valued at 

 £10 ; 000. As alleged, this fishery became nearly destroyed from 

 over-dredging. Under M. Coste's directions in 1859, two Impe- 

 rial pares, Grand Ces and Grastorbe, were constructed. The 

 first collectors used were wood, to which shells, &c, were attached 

 by a resinous cement ; these decayed rapidly, and were replaced 

 by tiles, shells, and stone collectors. 



The first two years the proceeds were very considerable ; sub- 

 sequently there was a great falling off — but 1869 appears to have 

 produced a very large crop. During six years the quantity 

 removed from the Imperial pares was nearly sixteen millions of 

 oysters — this is independent of the pares of private proprietors 

 — many of them concessions or allotments by Government, varying 

 from one to eight acres. 



A long grass-like weed — Zostera marina — which grows in 

 great quantity on the beds, proves very useful in protecting the 

 oysters at low tide from the heat of the sun. 



Besides the area under cultivation there are several natural 

 beds in different parts of the basin, all subject to the Government 

 regulations which will be hereafter more particularly described. 



The great bulk of the oysters bred at Arcachon are sent to 

 Marennes and Tremblade, where the green tint so much esteemed 

 in France is imparted to the beard of the oyster, but against 

 which so unjust a prejudice exists in England as regards the Essex 

 oysters, most of which are in consequence sent to France — the 

 cause of the greenness being probably the same in both instances — - 

 the presence of Diatomacese (see figures 11, 12) and not, as at 

 Falmouth, owing to the presence of copper. Oysters impregnated 

 with the latter are always green in the body, whilst those of 

 Marennes and Essex are green only in the beard or " fin." 



Fig. 1 1 — Achnanthes longipes : a Diatom found at Chattellalion. 



B 2 



