THE GARDEN SNAIL 



By JOHN J. WA O 



Author of "Life Histories of Familiar Plants," "S •e Nature Biographies," etc. 

 Illustrated with Photographs by ■ le Author 



THE common Garden Snail {Helix Of course, the whole body is really movmg 



aspersa) is a strange animal, whose forward ; how the motion is effected 



dirty brown and grey shell, slimy science has yet to explain, 



■exudations, and destructive habits in Another remarkable feature about the 



our gardens, quite 

 ahenate it from our 

 sympathy. Neverthe- 

 less, the Nature lover 

 may spend many a 

 profitable hour in ob- 

 serving the curious 

 habits of this leisurely- 

 moving and even-paced 

 Gastropod — as the zoo- 

 logist prefers to call 

 it, which, in plain lan- 

 guage, means stomach- 

 foot. 



The lower exposed 

 part of the snail's bocty 

 •consists of a large and 

 broad muscular foot, 

 and by means of this 

 ■organ its locomotion 

 is accomplished. The 

 curious feature about this foot is that it 

 is never lifted when its owner is moving. 

 Its progress may be ever so closely watched 

 as it ghdes over a pane of glass, but all 

 that can be observed is a series of muscular 

 undulations passing from back to front 

 as the snail ghdes slowly forward. Al- 

 though the snail obviously makes head- 

 way, yet just how it travels is a complete 

 mystery ; the whole of the time the base 

 of the foot is closely applied to the glass, 

 and is never seen to wrinkle with the 

 forward movement. 



The successive waves, commencing at 

 the posterior end, are seen to travel c()m- 

 pletely through the substance of the foot 

 to the anterior end, and the foot, therefore, 

 appears to be continually shortening at 

 its base and lengthening its fore part. 



THE GARDEN SNAIL 



snail's locomotion is 

 that it always travels 

 at the same pace ; 

 whether over loose or 

 rough soil, the bark 

 of a tree, a perpen- 

 dicular wall, or a sheet 

 of glass, the pace 

 is always the same. 

 If it is pursued by 

 an enemy it cannot 

 hurry, neither can it 

 move backwards ; its 

 muscular mechanism 

 having been put into 

 use, it must run its 

 course. Its only de- 

 fence is completely to 

 stop the machinery, 

 as it were, and start 

 another section by 

 which it is withdrawn into its shell. 



Seeing that an uneven, a too steep, or 

 a too smooth surface always impedes our 

 progress, it is at first astonishing that 

 the soft body of the snail should main- 

 tain its even pace irrespective of differences 

 in the surface over which it moves. It 

 is, however, by means of the shme, or 

 mucus, which it secretes that this equahty 

 of motion is obtained. According to the 

 character of the surface in contact with 

 the snail's body a greater or less quantity 

 of this lubricating fluid is depositetl, 

 and in this slime the moliile foot always 

 glides with the same amount of friction ; 

 hence the pace remains the same. 



Around that part of the snail jirotected 

 by the shell is a thin loose skin known as 

 the mantle, and from secretions from the 



735 



