580 SNAILS. 



They have but one coat ; and the vitreous, the aque- 

 ous, and the crystalline humours are (though not 

 very distinctly) to be seen. These eyes the animal 

 can direct to different objects at pleasure, by a regu- 

 lar motion out of the body; and sometimes it hides 

 them, by a very swift contraction into the belly. Un- 

 der the smaller horns is the animal's mouth ; and 

 though its substance may appear too soft to be fur- 

 nished with teeth, yet it has no fewer than eight.-— 

 With these it chews leaves and other substances, 

 seemingly harder than any part of its own body; 

 and with these it even sometimes bites off pieces of 

 its own shell. 



The snail, when its shell is broken, has a power of 

 mending it. Sometimes the animals are seemingly 

 crushed to pieces j and, to all appearance, utterly 

 destroyed ; yet still they set themselves to work, and 

 with the slimy substance that they force from their 

 bodies, which soon hardens, they in a few days mend 

 ail their numerous breaches. All the junctures, 

 however, are very easily seen; tor these have a 

 fresher colour than the rest, and the whole shell in 

 some measure resembles an old coat patched with 

 new pieces. They are sometimes seen with eight 

 or ten of these patches. Still, however, though the 

 animal has the power of mending its shell, it cannot, 

 when Come to its full growth, make a new one. — 

 Swammerdam tried the experiment. He stripped 

 a snail of its shell, without injuring any of the blood- 

 vessels, retaining that part of the shell where the 

 muscles were inserted: but it died in three days af- 

 ter it lost its covering ; not, however, without ma- 



