246 MEANS OF DEFENCE OP INSECTS. 



of black, elevated, conical tubercles, of a hard sub- 

 stance; from all of these when touched the animal 

 emits a small drop of a white milky fluid, the smell of 

 which, De Geer observes, is almost insupportable, being 

 inexpressibly strong and penetrating. These drops 

 proceed at the same instant from all the eighteen scent- 

 organs; which forms a curious spectacle. The insect, 

 however, does not waste this precious fluid; each drop 

 instead of falling, after appearing for a moment and 

 dispensing its perfume, is withdrawn again within its 

 receptacle, till the pressure is repeated, when it re- 

 appears ''. 



I shall now introduce you to the true counterparts of 

 the skunk, which explode a most fetid vapour from the 

 ordinary passage. I have lately hinted thatthe scent of 

 many Carabidae is thus emitted. Harpalus prasinus, a 

 beetle of this tribe, combats its enemies with repeated 

 discharges of smoke and noise : but the most famous 

 for their exploits in this way are those, which on this 

 account are distinguished by the name of bombardiers 

 (Brachinus, F.). The most common species (B. cre- 

 pita7is, F.), which is found occasionally in many parts 

 of Britain, when pursued by its great enemy, Ccdosoma 

 Inquisitor, F., seems at first to have no mode of escape ; 

 when suddenly a loud explosion is heard, and a blue 

 smoke, attended by a very disagreeable scent, is seen 

 lo proceed from its anus, which immediately stops the 

 progress of its assailant : when it has recovered from 

 the effect of it, and the pursuit is renewed, a second 

 discharffe ajjain arrests its course. The bombardier can 



■ De Geer, v. 291. Compare Ray's Ldters, 13. See Pj-vte XV 11 1. 

 Fig, 1. 



