252 OF BIVALVED SHELL-FISH, 



from the head to the tail : thus the body of the animal, when cut 

 of the fhell, refembles a number of foft bits of flefh, threaded on a 

 firing. How it contrives to difengage its body from fo intricate an ha- 

 bitation ; how it makes a fubllance, to appearance ahTioft as thick as 

 one's wrifl, pafs through forty openings, each fcarcely admitting a goofe 

 quill, is not difcovered : but the fa6t is certain ; for the animal is often 

 found without its fhell i and the fhell more frequently without the ani- 

 mal. This animal, particularly that of the white light kind, is chiefly 

 found in the Mediterranean. When the fea is calm, they are obferved 

 floating on the furface ; fome fpreading their little fail ; fome rowing 

 with their feet, as if for life and death ; others floating on their mouths, 

 like a fhip keel upwards. If taken while thus employed, the extraordi- 

 nary mechanifm of their limbs for failing appears manifeft. The nau- 

 tilus is furnifhed with eight feet, which ilTue near the mouth, and may as 

 properly be called barbs : thefe arc connected to each other by a thin 

 . membrane, like that between the toes of a duck, but much thinner and 

 more tranfparent. Of thefe eight feet thus conne6ted, fix are fhort : 

 thefe are held up as fails to catch the wind ; the two others, being longer, 

 are kept in the water ; ferving, like paddles, to fleer its courfe. When 

 the weather is quite calm, and the animal is purfued from below, it ex- 

 pands only part of its fail, rowing with the refl: : when interrupted, or 

 alarmed from above, it inftantly furls the fail, catches in all its oars, 

 turns its fhell mouth downward, and finks to the bottom. Sometimes 

 it is feen pumping the water from its leaking hulk ; and, when unfit for 

 failing, deferts its fhell entirely. The forfakenhulk is feen floating along, 

 till it dafiaes, by a kind of fhipwreck, on the rocks or the fhore. 



OF BIVALVED SHEL L -FISH, O R SHELLS 

 OF THE OYSTER KIND. 



WE fliall find thefe in every refpeft inferior to fnails we have been 

 defcribing; in their fenlations j in their powers of motion; in their 

 gene;-ation. All the bivalve tribe are hermaphrodite, but require no aflifl- 

 ance from each other towards impregnation -, and a fingle muflTelor oyfter, 

 , were there no other in the world, would quickly replenifh the ocean. 

 1 V As 



