THE REASON WHY. 333 



" Notwithstanding they hearkened not unto Moses ; but some of them left it 



until the morning, and it bred worms, and stank : and Moses was wrath 



with them." EXODUS xvi. 



Kpiral body of the shell to turn, and so to wind its growth around 

 the centre. 



1309. Why has the snail four tentacula attached to its 

 head? 



Because the insect, having no other limbs, is provided with 

 those projecting members, the lower two serving as feelers 

 and the upper two also as feelers and eyes. These, projecting 

 in the front of the animal, impart to it a consciousness of surrounding 

 objects, and especially of those which lie in its path. 



1310. Why is the snail able to move, without feet ? 



Because it has attached to its body a fringe of muscular skin, 

 which is capable of considerable contraction and expansion, and by 

 alternately stretching and shortening this, the snail is able to draw 

 himself along. 



1311. Why do we see no snails in the winter time ? 

 Because they bury themselves in the ground, or in holes, where 



they remain in a torpid state for several months. Before th<>y 

 enter into the torpid state, they form with their slimy secretion, and 

 with some earthy matters which they collect, a strong cement with 

 which they seal up the opening to their shells. 



1312. Why can snails live in shells thus sealed ? 



Because they leave, in the thin wall by which they close them- 

 selves in, a small hole, too small to admit water, but large enough 

 to let in sufficient air to carry on their feeble respiration during 

 their winter sleep. 



1313. Why do insects abound in putrid waters, and in 

 decaying substances ? 



Because they have been endowed with appetites and with 

 constitutions that enable them to live upon and to enjoy corrupt 

 matter. In this point of view the maggots of flies are exceedingly 

 useful; a dead carcass is speedily threaded by them in every 

 direction ; thus that corrupt matter which, in a large mass, would 

 poison the air, is taken up in small portions by millions of living 

 bodies, and by them dispersed, and becomes innoxious. 



