27i INDIRECT BENEFITS DERIVED FROM INSECTS. 



the water, pulling off their wings with great adroitness 

 and devouring in an instant the contents of the body. 

 From the number of insects of this tribe which are every 

 where to be observed, we may conjecture how useful 

 they must be in preventing too great a multiplication of 

 the other species of the class to which they belong. 



Lastly, under this head, not to dwell upon some other 

 apterous genera, devourers of insects, as the scorpion and 

 centipede, Phalangium and Solpuga, must be enume- 

 rated the whole world of Spiders, extremely numerous 

 both in species and individuals, which subsist entirely 

 upon insects, spreading with infinite art and skill their 

 nets and webs to arrest the flight of the heedless and un- 

 wary summer tribes that fill the air, which are hourly 

 caught by thousands in their toils ; one of them (Aranea 

 13-guttata Rossi), we are told, even attacking the re- 

 doubted Scorpion 1 . 



So much for the insect benefactors to whom it is given 

 in charge to keep the animals of their own class within 

 their proper limits ; and I cannot doubt that you will re- 

 cognise the goodness of the Great Parent in providing 

 such an army of counterchecks to the natural tendency 

 of almost all insects to incalculable increase. But before 

 I quit this subject I must call your attention to what may 

 be denominated cannibal insects, since in spite of those 

 declaimers who would persuade us that man is the only 

 animal that preys upon his own species b , a large number 



4 Thiebaut de Berneaud's Voyage to Elba, p. 31. 

 b " Even Tyger fell and sullen Bear 



Their likeness and their lineage spare. 

 Man only mars kind nature's plan, 

 And turns the fierce pursuit on Man ! " 



Scott's Jlokfby, canto iii. 1. 



