TESTACEOUS FISHES. 



691 



laboriously and slowly forward, so the razor- 

 shell h-is only a power of sinking point down- 

 ward. The shells of (his animal resemble no- 

 thing so much as the haft of a razor ; and by 

 this form it is better enabled to dive into the 

 soft sand at the bottom. All the motions of 

 this little animal are confined to sinking or 

 rising a foot downwards or upwards in the 

 sand, for it never leaves the spot where first 

 it was planted. From time to time it is seen 

 to rise about half way out of its hole ; but if 

 any way disturbed, it sinks perpendicularly 

 down again. Just over the place where the 

 razor buries itself, there is a small hole like a 

 chimney, through which the animal breaths, 

 or imbibes the sea-water. Ujton the deser- 

 tion of the tide, these holes are easily distin- 

 guished by the fishermen who seek for it ; and 

 their method of enticing the razor up from the 

 depth of its retreat is by sprinkling a little sea- 

 salt upon the hole. This, melting, no sooner 

 reaches the razor below than it rises instantly 

 straight upwards, and shows about half its 

 length above the surface. This appearance, 

 however, is instantaneous ; and if the fisher 

 does not seize the opportunity, the razor buries 

 itself with great ease to its former depth. 

 There it continues secure ; no salt can allure 

 it a second time ; but it remains unmolested, 

 unless the fisher will be at the trouble of dig- 

 ging it out sometimes two feet below the sur- 

 lace. 



Such are the minute differences between 

 bivalved shell-fish ; but in the great outlines 

 of their nature they exactly resemble each 

 other. It is particularly in this class of shell- 

 fish that pearls are fo-nv! in great abundance; 

 aii'l it is in the internal parts of those shells 

 tint are of a shining silvery colour that these 

 gp'ris vire usually generated ; but the pearl is 

 also found to breed as well in the muscle or 

 the se illop ;is in the oyster. In fact, it is found 

 in all bivalved shells, the insides of which re- 

 semble that well known substance called 

 mother-of-pearl. 



Whether pearls be a disease or an accident 

 in th" animal is scarcely worthy inquiry. The 

 corn non opinion is, that they are a kind of 

 calculus concr<'ti.>i) in tin- body of the animal, 

 some \hat resembling a stone in the bladder, 

 and are consequently to be considered as a 

 disorder. It is said, in confirmation of this 

 opinion, that those coasts upon which pearls 



NO. 59 & 60. 



are fished, are very unhealthy ; and therefore 

 most probably oysters share the general in- 

 fluence of the climate ; it is also added, that 

 those oysters in which pearls are found are 

 always ill-tasted, which is a sign of their be- 

 ing unsound ; and lastly, it is asserted that the 

 pearl grows sometimes so big as to keep the 

 shells of the animal from shutting, and that 

 thus it dies by being exposed. It is easy to 

 see the weakness of these assertions, which 

 seem neither true nor amusing. To answer 

 them in their own way : If a stone in the 

 bladder be a disorder, a stone in the stomach 

 of an ostrich is a benefit, and so it may be in 

 the shell of an oyster. If the shores where the 

 pearls are fished be unwholesome to man, that, 

 instead of being disadvantageous, is so much 

 the more lucky for the oyster. If the pearl 

 oysters are the worst tasted, so are kites and 

 ravens among birds ; and yet we know that 

 they are healthy and long-lived animals : if 

 the oyster had ever its shell kept asunder by 

 the pearl within it, that would be a disease 

 indeed : but this, in reality, never happens ; 

 for the oyster that breeds a large pearl always 

 breeds a large shell, and the shell itself indents 

 to receive its impression. The pearl upon the 

 whole seems bred from no disorder in the ani- 

 mal, but accidentally produced by the same 

 matter that goes to form the shell. The sub- 

 stance, which is soft at first, quickly hardens; 

 and thus, bv successive coats, layer over layer, 

 the pearl acquires its dimensions. If cut 

 through it will be found to consist of several 

 coats, like an onion; and sometimes a small 

 speck is seen in the middle, upon which the 

 coats were originally formed. 



All oysters, and most shell fish, are found 

 to contain pearls ; but that which particularly 

 obtains the name of the pearl oyster, has a 

 large strong whitish shell, wrinkled and rough 

 uithout, and within smooth and of a silver 

 colour. From these the mother-of-pearl is 

 taken, which is nothing more than the inter- 

 nal coats of the shell, resembling the pearl in 

 colour and consistence. This is taken out 

 and shaped into the variety of utensils which 

 are found so beautiful, but the pearl itself is 

 chiefly prized; being found but in few oysters, 

 and generally adhering, sometimes making a 

 print in the body of the shell, sometimes at 

 large within the substance of the fish. 



There are a great number of pearl fisheries 



