222 NATURAL THEOLOGY. 



body wliicli was attached to it. This expedient, so new to 

 us, proves to be no other than what the Author of nature has 

 employed in the gossamer S'pider. We frequently see this 

 spider's thread floating in the air, and extended from hedge 

 to hedge, across a road or brook of four or five yards width. 

 The animal which forms the thread has no wings where 

 with to fly from one extremity to the other of this line, nor 

 muscles to enable it to spring or dart to so great a distance ; 

 yet its Creator has laid for it a path in the atmosphere, 

 and after this manner. Though the animal itself be heavier 

 than air, the thread which it spins from its bowels is spe- 

 cifically lighter. This is its balloon. The spider, left to 

 itself, would drop to the ground ; but being tied to its thread, 

 both are supported. We have here a very peculiar provis- 

 ion ; and to a contemplative eye it is a gratifying spectacle 

 to see this insect M^affced on her thread, sustained by a levity 

 not her own, and traversing regions which, if we examined 

 only the body of the animal, might seem to have been ibr- 

 bidden to its nature. 



I must now crave the reader's permission to introduce 

 into this place, for want of a better, an observation or two 

 upon the tribe of animals, whether belonging to land or 

 water, which are covered by shells. 



I. The shells of syiaiU are a wonderful, a mechanical, 

 and, if one might so speak concerning the works of nature, 

 an original contrivance. Other animals have their proper 

 retreats, their hybernacula also, or winter-quarters, but tho 

 snail carries these about with him. He travels with his 

 tent ; and this tent, though, as was necessary, both light and 

 thin, is completely impervious either to moisture or air. 

 The young snail comes out of its ^gg with the shell upon its 

 back ; and the gradual enlargement which the shell receives, 

 is derived from the slime excreted by the animal's skin. 

 Now the aptness of this excretion to the purpose, its property 

 of hardening into a shell, and the action, whatever it be, of 



