BIVALVE MOLLUSCANS. '257 



St. James, because the pilgrims to the shrine of 

 St. James of Compostella, in Galicia, were 

 accustomed to ornament their cloak and hat 

 with them. 



I shall next make some observations upon the 

 bivalve just mentioned, the oyster, which of all 

 shell-fish, though it is one of the rudest and least 

 sightly, has from every age been most in request, 

 as a favourite article of food. This gift of Provi- 

 dence is widely dispersed, being found on the 

 coasts of Europe, Asia, and Africa ; those that 

 frequent our own are reckoned the best of all. 

 They are not a roving animal, but when they 

 leave the matrix, they fix themselves to 

 rocks or any substance that falls in their way, 

 which they seldom quit. Like other Molluscans, 

 they are hermaphrodites, and are stated by 

 Poli, the great luminary of conchology, to con- 

 tain 1,200,000 eggs, so that a single oyster might 

 give birth to 12,000 barrels!! Providence has 

 thus taken care that the demands made upon 

 them to gratify the appetite of his creature man, 

 shall not annihilate the race. These also are 

 the only shell-fish that man has thought it worth 

 his while to cultivate, by keeping them in cer- 

 tain pits formed for the purpose, called amongst 

 us beds, and to which the salt water is admitted 

 only at high tides : and in these the green oysters 

 are said to be produced ; marine plants of that 

 colour, the growth of which is favoured by the 



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