244 On the Economical Uses of some species of Testacea. 



six to nine men each, were entered at the custom house of Cancale, 

 in France, and carried back one hundred and nineteen millions four 

 hundred and seventy three oysters, chiefly to London. On an aver- 

 age of 1831 — 1832, the imports into the same city amounted to 

 fifty two thousand and ninety five bushels a year. In or about 1786, 

 Glasgow consumed twenty thousand annually, which were carried 

 from Leith on horseback or by carts, across the country. The quan- 

 tity in the present day must be much greater. In 1803, the con- 

 sumption of Paris was estimated at one million dozen, selling on an 

 average at six sous per dozen. 



JVatural habits. — The European oyster is smaller, thinner, and 

 more rounded than the American, while the lower valve is less con- 

 cave or vaulted, it is not beaked, and the fish, compared with the size 

 of the shell, is smaller and of a different flavor; there are besides, va- 

 rious other differences, and their habits are so very dissimilar that there 

 can be no doubt at all of their being distinct species. The European 

 oyster is found only adhering to rocks and stones, or occasionally to 

 very strong clayey bottoms, and should these be washed away, the 

 oyster beds perish. The fish is viviparous, and the young produced 

 with a perfectly formed shell. They are, when first emitted, quite 

 transparent, and they swim with great quickness, by means of a 

 membrane extending out of the shell. So small are they in this 

 state that Van Leeuwenhoek computes that one hundred and twenty 

 of them in a row would extend an inch, and consequently a globular 

 body, whose diameter is an inch, would, if they were round, be 

 equal in size to one million seven hundred and twenty eight thousand 

 of them ! The vulgar opinion, and that on which the restraining 

 laws have been framed is, that the period of spawning is May, at 

 which time the young, or spat, is found adhering to the rocks. But 

 as the young, as described above, are found in the parents perfectly 

 formed and alive in the month of August, this is most probably the 

 period of parturition, though it be not till May that they become 

 fixed or sufficiently grown to be seen by the common observer. At 

 this time they are about the size of a sixpence, and comparatively 

 hard and firm, and have been well compared to a drop of candle 

 grease in water. In two, or at farthest three years, they are fit for 

 the table. The age to which it attains is probably great, but after 

 having arrived at its full size, the valves are thickened, instead of 

 being increased in length or breadth. From May to July, both the 

 male and female oyster are said to be sick, and are in thin and poor 



