PERFECT SOCIETIES OF INSECTS. 67 



naced or attacked, no insects show a greater degree of 

 it. Providence, moreover, has furnished them with wea- 

 pons and faculties which render it extremely formidable 

 to their insect enemies, and sometimes, as I have related 

 on a former occasion, a great annoyance to man him- 

 self 3 . Two strong mandibles arm their mouth, with 

 which they sometimes fix themselves so obstinately to 

 the object of their attack, that they will sooner be torn 

 limb from limb than let go their hold ; and after their 

 battles, the head of a conquered enemy may often be seen 

 suspended to the antennae or legs of the victor,~-a tro- 

 phy of his valour, which, however troublesome, he will 

 be compelled to carry about with him to the day of his 

 death. Their abdomen is also furnished with a poison- 

 bag (Ioterium\ in which is secreted a powerful and veno- 

 mous fluid, long celebrated in chemical researches, and 

 once called formic acid, though now considered a modi- 

 fication of the acetic and malic b ; which, when their ene- 

 my is beyond the reach of their mandibles (I speak here 

 particularly of the hill-ant, or F. rufa\ standing erect 

 on their hind-legs, they ejaculate from their anus with 

 considerable force, so that from the surface of the nest 

 ascends a shower of poison, exhaling a strong sulphu- 

 reous odour, sufficient to overpower or repel any insect 

 or small animal. Such is the fury of some species, that 

 with the acid, according to Gould c , they sometimes partly 

 eject, drawing it back however directly, the poison-bag 

 itself. If a stick be stuck into one of the nests of the 



3 VOL. I. p. 122. 



b See Fourcroy, Annales dit Museum, no. 5. p. 338, 342. Some, 

 however, still regard it as a distinct acid. c p. 34. 



F 2 



