MOLLUSCS AS FOOD 295 



than 43 tons 10 cwts. of them was seized and condemned at 

 and near Billingsgate Market. On the Continent the consump- 

 tion is much greater than with us. 



The mussel is gready valued as a bait in British line-fishing, 

 particularly on the coast of Scodand. The yield in that country 

 for 1902 amounted to 95,663 cwts., valued at ^5445, which con- 

 trasts strongly with the 247,186 cwts., worth ^14,506, collected 

 in 1892. The meaning of the steady diminution which has 

 been going on for some years has reference to the displacement 

 of line-fishing by trawling. The same thing has been happening 

 with regard to "clams" (species of Pecten and various other 

 bivalves), another valuable bait in Scottish line-fishing. The 

 quantity of clams taken in 1892 was 20,769 cwts. (^2736), but 

 in 1902 only 4320 cwts. (^586). 



Mussel-Ctdture. — As in the case of the oyster, the eggs hatch 

 out into free-swimming "fry", which after a time attach them- 

 selves to various objects, not, however, by the substance of one 

 valve, but by silky byssus threads. Nor is the mussel obliged 

 to spend the whole of its fixed life in one spot, for it can cast 

 off the threads, and crawl away to some distance, if adverse 

 circumstances render a change of residence desirable. Import- 

 ant musselries were established some years ago at Montrose, 

 and previously barren ground was made very valuable. The 

 principle involved essentially consists in reserving certain beds 

 for the production of "seed", as in the case of the strictly- 

 preserved natural oyster-banks on the French coast (see p. 289). 

 From these beds the young mussels are collected and planted 

 out on other areas. 



On the Baltic coast of Germany tree-branches are thrust into 

 the sea-floor in shallow water (fig. 12 16), serving as collectors 

 for the fry, which grow upon them to a marketable size. After 

 from three to five years they are pulled up, weighed, and sold 

 with their living crop still adhering. 



At some points of the French sea-board, especially at Es- 

 naudes on the west coast, elaborate mussel-farming is practised, 

 on what is known as the " bouchot " system. Each bouchot is 

 a V-shaped or W-shaped collection of stakes driven into the 

 mud, with the opening directed seawards. Adjacent stakes are 

 connected by interwoven branches, and the 500 bouchots of the 

 Esnaude musselry have a collective length of not far short of 



