4S8 Hmtdbook of Nature-Study 



VII. OTHER INVERTEBRATE-ANIMAL STUDY 



THE GARDEN SNAIL 



Teacher's Story 



ERCHANCE if those who speak so glibly of a "snail's pace" 

 should study it, they would not sneer at it, for carefully 

 observed, it seems the most wonderful method of locomotion 

 ever devised by animal. Naturally enough, the snail can- 

 not gallop since it has but one foot ; but it is safe to assert 

 that this foot, which is the entire lower side of the body, is a 

 remarkable organ of locomotion. Let a snail crawl up the side of a 

 tumbler and note how this foot stretches out and holds on. It has 

 flanges along the sides, which secrete an adhesive substance that enables 

 the snail to cling, and yet it also has the power of letting go at will. The 

 slow, even, pushing forward of the whole body, weighted by the un- 

 balanced shell, is as mysterious and seemingly as inevitable, as the march 

 of fate, so little is the motion connected with any apparent muscular 

 effort. But when his snailship wishes to let go and retire from the world, 

 this foot performs a feat which is certainly worthy of a juggler; it folds 

 itself lengthwise, and the end on which the head is retires first into the 

 shell, the tail end of the foot being the last to disappear. And now find 

 your snail! 



Never was an animal so capable of stretching out and then folding up 

 all its organs, as is this little tramp who carries his house with him. Turn 

 one on his back when he has withdrawn into his little hermitage, and 

 watch what happens. Soon he concludes he will find out where he is, and 

 why he is bottomside up; as the first evidence of this, the hind end of the 

 foot, which was folded together, pushes forth ; then the head and horns 

 come bubbling out. The horns are not horns at all, but each is a stalk 

 bearing an eye on the tip. This is arranged conveniently, like a marble 

 fastened to the tip of a glove finger. When a snail wishes to see, it 

 stretches forth the stalk as if it were made of rubber; but if danger is per- 

 ceived, the eye is pulled back exactly as if the marble were pulled back 

 through the middle of the glove finger; or as a boy would say, "it goes 

 into the hole and pulls the hole in after it." Just below the stalked eyes, 

 is another pair of shorter horns, which are feelers, and which may be 

 drawn back in the same manner; they are used constantly for testing the 

 nature of the surface on which the snail is crawling. It is an interesting 

 experiment to see how near to the eyes and the feelers we can place an 

 object, before driving them back in. With these two pairs of sense 

 organs pushed out in front of him, the snail is well equipped to observe 

 the topography of his immediate vicinity; if he wishes to explore above, 

 he can stand on the tip of his tail and reach far up; and if there is any- 

 thing to take hold of, he can glue his toe fast to it and pull himself up. 

 Moreover, I am convinced that snails have decided views about where 

 they wish to go, for I have tried by the hour to keep them marching length- 

 wise on the piazza railing, so as to study them; and every snail was 

 determined to go crosswise and crawl under the edge, where it was nice 

 and dark. 



