ADAPTATION 



329 



secretions produced by these two types of glands form the 

 "poison" of the bee's sting. The two substances are mixed 

 in the bulb at the base of the sting and, when the sting is used, are 

 forced through the channel formed by the shaft of the sheath and 

 the two darts, by a pump located within the bulb. The darts 

 are moved along the edges of 

 the sheath by the contraction 

 of abdominal muscles. 



The damage to a victim of a 

 bee's sting is caused by the 

 action of the poisonous fluid 

 injected into the wound. The 

 effect of this poison on insects 

 like houseflies and blowflies is 

 fatal; on man it produces a very 

 painful result. There is some 

 question as to which of the con- 

 stituents of the poison sac is the 

 effective toxic agent. If the 

 sting remains in the wound, 

 the poison sac and the adjacent 

 organs in the tip of the bee's 

 abdomen are torn out with the 

 sting and the bee loses its life. 

 The adaptive value of the sting 

 might be questioned, since its 



& . , ' , ,, Fig. 184.— Sting of the honeybee, 



use frequently causes the death Apis me mfi cat dissected, d, serrated 



Of the User; but this objection darts; V, feelers provided with tactile 



, sense organs; m, muscles, attached at the 



disappears when one under- lower edge to the body wall, whose 



Stands that the activities of the contractions force the darts into the 



. f. , wound; p. s., poison sac with a duct lead- 



members oi the colony ol bees ing to the darts; Pi0#i poison gland; s, 



center about the welfare of the sheath into which the darts can be 



. ,, ,, . ,. . , withdrawn. Alkaline gland not shown. 



colony rather than the individ- 

 ual. The honeybee is a social insect, and the protective adapta- 

 tions in such organizations are directed toward safeguarding the 

 social unit, the colony, rather than the individual. In such a 

 colony, worker bees, which are abortive females, and the queen, 

 the sexually active female, have stings. The drones or males have 

 no stings. The workers use the sting indiscriminately on enemies 

 of all kinds; the queen reserves her sting for use on other queens. 



