342 ON THB StIM OP TEJ5FJ. 



Insects contract sects in the cnrrant, and many other leaves, that show the 

 wire. p 0wer f ^ e e j asr ; c w j re? as muc Ji as an y thing yet men- 

 Honed. Nature has taught them, to draw up these spiral 

 vessels, to make themselves nests, in which to deposit their 

 eggs and young ; and any one may see in what manner it is 

 done, and how the leaf is shortened. 



Heat contracts 5 ^« I tools, sl quantity of these spiral vessels from a cab- 



the spiral wire, bage leaf, and plaeed them on a long netting needle in my 

 solar microscope, that the motion might be extremely visi- 

 ble, and made my assistant hold a candle to the other end 

 of the needle. As the heat approached it, the vessels were 

 agitated inexpressibly, and appeared wreathing like a worm, 

 till with one effort they flung themselves off the needle. 

 The fresh water conferva, and the dodder tribe, are the 

 only plants without leaves, that have the spiral vessels, that 

 I am acquainted with. The former is almost formed of it; 

 and the sensitive plants have scarce more motion than the 

 common green conferva. I have seen it draw itself up, 

 then turn with a sudden motion, and surround a pin, coiling 

 up it like a worm; and it will continue to move thus for 



Strength of more than an hour after it is taken from the water. In the 



lv v^ak P iartsot * ea ^ s * em °^ ^ e § erai " um cordifolium the spiral vessels are 

 vegetables. so very tough, and so very tightly coiled, that I have by 

 great care drawn up the leaf by their means ; but this is dif- 

 ficult to be done. Some may imagine, that these spiral wires 

 are too delicate to turn the leaf or flower ; but can any one 

 say this, w ho is in the constant habit of dissecting plants ? 

 or who ha? seen the extreme delicacy of flowers, and yet the 

 force they will exert, or the tenderness of the young shoot- 

 ing plant, and yet the strength with which it will force its 

 way through brick and mortar, and even through solid 

 stones? The works of man are effected by using strong ma- 

 terials, when powerful ends are in view ; but the works of 

 God are performed in a more wonderful manner, the most 

 delicate means produce the greatest ends. Look on the 

 _^. vegetable cuttings; it is ihe aggregate of such pieces which 



forms our ships, and which stands the united attacks of 

 winds and waves. View the metals, as they first grow or 

 shoot into crystallization in the Arbor Diana? or the leaden 

 tree; who would recoguize the destructive bomb, or the 



hardened 



