544 THE MUSCLE. 



membrane the animal is able to thrust out of the shell, 

 and with it makes a kind of furrow in the sand, whilst 

 the muscle travels edgeways in a convenient kind of 

 groove. 



The muscle cannot be entirely called a marine ani- 

 mal, as it is found in lakes and rivers, as well as in the 

 sea ; though, in the latter, they are to be met with in 

 greater abundance, and likewise of a larger make. 



THE OYSTER. 



Though the internal conformation of the oyster 

 hears some resemblance to the muscle, and the intes- 

 tines, lungs, and heart are nearly the same, yet only one 

 side of the shell is concave, and in that the animal al- 

 ways dwells. The muscle, as we have observed, is ca- 

 pable of erecting itself upon its edge, and of proceed- 

 ing forwards, although with a very slow pace ; but the 

 oyster remains in a stationary situation, and attaches 

 itself either to rocks, stones, or sea-weeds, and may 

 frequently be seen in the tropical climates hanging in 

 clusters to different branches of trees whose boughs 

 happen to bend over that element in which the fish na» 

 turally resides. This adhesive quality which the crea- 

 ture possesses is generally produced from a glutinous 

 cement, though sometimes it is observed growing to 

 the rocks by threads which appear to have taken root 

 upon the shell. 



Oysters usually cast their spawn in May, which ge- 

 nerally adhere to some hard substance, and has the ap- 

 pearance of drops of candle-grease, which in two or 

 three days acquires a callous covering, though it is 

 three years before they are large enough to eat. It is 

 the custom at Colchester, and other parts of the king- 

 dom where the tide settles on marshy land, to pick up 



