278 PHYSIOLOGY. 



plex apparatus, which in the bee is used both as 

 a weapon of defence and offence, is a hollow horny 

 tube or scabbard, inclosing two bearded darts, 

 which can be thrust a short way beyond the 

 sheath, though the whole appears to the naked 

 eye like the solid point of the minutest needle. 



This apparatus is moved by muscles which, 

 though invisible to the eye, are yet strong enough 

 to force the sting to the depth of one twelfth of 

 an inch through the thick cuticle of a man's hand. 

 It is articulated by thirteen scales to the lower 

 end of the insect's body ; and at its root are situ- 

 ated two glands or ducts, from which the poison 

 is secreted : these glands uniting in one duct, eject 

 the venomous liquid along the groove formed by 

 the junction of the two piercers. There are four 

 beards on the outside of each piercer : when die 

 insect is prepared to sting, one of these piercers, 

 having its point a little longer or more in advance 

 than the other, first darts into the flesh, and being 

 fixed by its foremost beard, the other strikes in 

 also, and they alternately penetrate deeper and 

 deeper, till they acquire a firm hold of the flesh 

 with their hooks, and then follows the sheath en- 

 tering and conveying the poison into the wound. 

 The action of the sting, says PALEY, affords an 

 example of the union of chemistry and mechanism : 

 of chemistry, in respect to the venom which can 

 produce such powerful effects : of mechanism, as 



