4^4 OF BIVALVED SHELL-FISH. 



Its inftrument of motion, from place to place, is that mufcdlar fub- 

 fiance refembling a tongue, which is in fome two inches long, in others 

 not one. This, being thruft out of its fhell, is capable of making a 

 flight furrow in the fand. By means of this furrow the muflel can ere6t 

 itfelf on the edge of its fhell ; and prolonging this furrow as it advances, 

 it projeds its tongue, that anfwers the purpofe of an arm, and thus car- 

 ries its fhell edge -ways, as in a groove. Where it determines to refide, 

 it fixes the ends of its beard ; and thus, like a fhip at anchor, braves 

 all the agitations of the water. Sometimes the animal is attached by a 

 large number of threads ; fometimes but by three or four, that feem 

 fcarce able to retain it. It lives on little earthy particles that the water 

 tranfports to its Hiells, and perhaps the flelh of the moil diminutive animals. 

 However, fome of this kind have been found a foot long. Of the beard 

 the natives of Palermo fometimes make gloves and flockings. 



Thefe fhell-nfn are found in lakes, rivers, and the fea. Thofe of lakes 

 often grow very large ; but they feem folitary, and are found generally 

 feparate. Thofe of rivers are not fo large, but more numerous : the fea 

 muffel is the moil abundant. Thefe are often bred artificially in falt- 

 water marlhes overflowed by the tide : being thrown in at proper feafons, 

 undifturbed by the agitations of the fea, and not preyed on by their pow- 

 erful enemies, they call their eggs, which foon become mature, and are 

 generally found in clufters of feveral dozen together. It requires a year 

 for the peopling a muffel-bed j fo that, if the number confifts of forty 

 thoufand, a tenth part may annually be left for peopling the bed anew. 



The OYSTER differs little from the mulTd, except in its thick- 

 nefs of fhell, and greater im.becillity. Has organs of life and refpira- 

 tion, very voluminous inteftines, a liver, lungs, and heart. Is felf-im- 

 prcgnatedj opens its fhells to receive the influx of water, and is ftrongly 

 attached to its fhell both above and below. Thefe fhells are not equal, 

 one being cupped, the other flat ; it always refts on the cupped fhell, 

 for if it lay on the flat fide it would lofe all its water. Its fhells are 

 fo flrongly lined and defended, that no animal will attempt to pierce them. 

 But it often ferves as an obje6t to which pipe-worms, corallines, and 

 other little animals, fix their habitation, and live in fecurity. Among 

 the number of thefe is a little red worm, often found on the fhell ; which 

 fome erroneoufly fuppofed to impregnate their fpawn. The oyfter is 

 utterly unable to change its fituation ; but is attached very firmly to 

 objefls. Rocks, Hones, timber, fea weeds, all feem proper to give it a 

 fixture, and to fecure it againll the agitation of the waves. Nothing 



fo 



