278 INDIRECT BENEFITS DERIVED FROM INSECTS. 



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 *, a large number 

 of insects are guilty of the same offence. Reaumur tells 

 us, that having put into a glass vessel twenty caterpillars 

 of the same species, which he was careful to supply with 

 their appropriate food, they nevertheless devoured each 

 other until one only survived''; and De Geer relates se- 

 veral similar instances'^. The younger larvae of Calosoma 

 Sijcophanta often take advantage of the helpless inacti- 

 vity into which the gluttony of their maturer comrades has 

 thrown them, and from mere wantonness it should seem, 

 when in no need of other food, pierce and devour them. A 

 ferocity not less savage exists amongst the Mantes. These 

 insects have their fore legs of a construction not unlike 

 that of a sabre ; and they can as dexterously cleave their 

 antagonist in two, or cut off his head at a stroke, as the 

 most expert hussar. In this way they often treat each other, 

 even the sexes fighting with the most savage animosity, 

 llosel endeavoured to rear several specimens of M. reli- 

 giosa, but always failed, the stronger constantly devour- 



^ " Even Tiger 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 Rokcbj/, canto iii. 1. 



" Reaumur, ii. 413. <^ De Geer,i. 533. iii. 3G1. v. 400. vi. 91. 



