the true nature of Instinct* 23 



pressing its conscious mind, and producing the effects of the most 

 perfect science ; thereby accomplishing those objects which con- 

 stitute the ends of its existence. No effect can be produced without 

 a cause, and the Bee is either a scientific and intellectual being, 

 or it is the instrument of an agency that is of such a quality, 

 operating in and upon its animal mind, in a sphere above its 

 proper perception. 



Other less familiar, but not less wonderful instances of the me- 

 chanical and even philosophical powers exerted in the actions of 

 insects, are exhibited to us in whatever quarter we contemplate 

 their economy. The larva of a small Moth, (P. Tinea serratella 

 L.) constructs a little cylindrical tower for its residence upon the 

 surface of a leaf, and uses the utmost ingenuity to fix and retain it 

 in a position perpendicular to the site, by attaching silken threads 

 from a protuberance at its base to the surrounding surface ; and 

 when the stability of its habitation is threatened by external vio^. 

 lence, it produces a vacuum by drawing itself up to the summit of 

 its tower, which at other times it completely fills ; " and thus as 

 effectually fastens it to the leaf as if an air-pump had been em* 

 ployed ;" and in order to preserve the power of forming this va- 

 cuum, the insect never eats through the lower epidermis, or infe- 

 rior surface of his esplanade on the leaf: — yet so insignificant is 

 this little creature as to its bulk, that its castle appears like a small 

 spine on the leaf to which it is attached.* 



Equally curious is the history of insect architecture in other in- 

 stances, as in the Aquatic Spider, ( Aranea aquatica,) whose habi- 

 tation " is built in the midst of water, and formed, in fact, of air !" 

 This creature spins a frame work for her intended chamber, which 

 she attaches to the leaves of aquatic plants growing at the bottom 

 of the water, and having spread over the threads which form this 

 frame work a transparent varnish resembling liquid glass, and very 

 elastic, she next spreads over her belly a pellicle of the same ma- 

 terial, and ascending to the surface of the water, by some means 

 not fully ascertained, transfers a bubble of air beneath this pelr 

 licle, and then descending to her structure, discharges the bubble 

 into it, until, by successively repeating the operation, she effects 

 * Kirby and S pence, vol. i, p. 462. 



