UNIVALVES. 165 
Helices belong to a very numerous and compre- 
hensive tribe of terrestrial animals, which are un- 
provided with feet. But the want of these is 
obviated by such a disposition of the muscles and 
fibres of the trunk, as to render it capable of a 
progressive and undulatory movement, in any direc- 
tion to which the will of the animal determines it. 
This undulatory motion occasions the exudation 
already noticed, which not only materially assists 
the common Helix in adhering to extraneous sub- 
stances, and climbing walls and trees in quest of 
food, but is also essential to its safety, as it has 
frequently occasion to travel along ceilings with the 
shell reversed. Snails, however, generally remain 
quiet, and seldom move abroad, excepting when in 
search of food. 
But why such care to provide for the security, 
and promote the comfort of an obscure shell-fish ? 
Let this great truth be solemnly impressed on 
our minds: God has made nothing in vain. It 
is a clue that will safely conduct us through many 
intricate mazes of the great labyrinth of nature, 
as far, at least, as it is permitted for finite beings 
to explore them. In many instances we are unable 
to comprehend the intentions of the Deity with 
regard to the construction of his creatures: in 
others, their uses are so obvious that they cannot 
