WILD LIFE OF ORCHARD AND FIELD 



Yet why not? Snails are of vast multitude and 

 variety, ancient race, graceful form, dignified 

 manners, industrious habits, and gustatory excel- 

 lence ; quod est demonstrandum. 



Snails differ from other gasteropodous mollusks 

 chiefly in that they are provided with lungs, and 

 thereby are fitted to live in air instead of water. 

 Hence all true snails are terrestrial. As the snail 

 crawls upon a cabbage-leaf, all that you can see 

 of the body is the square head bearing two long 

 and two short horns, with the muscular base ta- 

 pering behind. There is an oily skin, and on 

 the back is borne a shell containing the rest of the 

 body, twisted up in its spiral chamber. Extend- 

 ing along the whole under surface of the body is 

 the tough, corrugated disk upon which the animal 

 creeps. This foot is the last part of the body 

 to be withdrawn into the shell, and to its end, in 

 a large division of pulmonate as well as marine 

 mollusks, is attached a little horny valve which 

 just fits the aperture of the shell and completely 

 stops it up when the animal is within. This is 

 called the operculum. The foot secretes a viscid 

 fluid which greatly facilitates exertion by lubri- 

 cating the path, and snails may often be traced 

 to their hiding-places by a silvery trail of dried 



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