INSECTS. 



4-79 



Spiders, and insects in the krva and perfect states, were 

 found to leave any visible track behind them when they 

 crawled over glass; and, by the aid of powerful magnify - 



Fig. 240. 



1, Foot and leg of Ophion. 2, Foot and leg of Blow-fly. 3, Foot and leg of 

 Drone-fly. (The small circles enclose the objects about the natural size.) 



ing-glasses, it was found that traces were left of an exceed- 

 ingly minute quantity of glutinous matter, which appeared 

 to have been emitted by the feet of these creatures ; and 

 subsequent experiments proved that the hair-like appen- 

 dages which form the brushes of Spiders and Flies are all 

 tubular. (See an interesting paper on this subject by 

 J. Hepworth, in the Microscopical Journal, 1854.) 



Fig. 241 represents the tongue and piercing apparatus 

 of the Drone -fly. This remarkable compound structure, 

 together with the admirable form and exquisite beauty of 

 the apparatus, must strike the mind with wonder and 

 delight, and lead the observer to reflect on the weakness 

 and impotence of all human mechanism, when compared 

 with the skill and inimitable finish displayed in the object 

 before us. The fleshy outer case which encloses it has 



