114 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



third valvula {3VI). The second valvifer rocks on the pivot of the 

 lower articular point of the first valvifer (C, h). The curved basal 

 rami of the two valvulae of each side are closely associated with 

 each other, that of the second valvula lying against the inner face 

 of the ramus of the first valvula. The two ventral first valvulae 

 slide freely on the lower edges of the completely united dorsal second 

 valvulae. The tip of the ovipositor (F) presents no unusual features. 



APIS MELLIFICA LINNAEUS 



The sting of the bee has been the subject of many anatomical 

 studies, and the structural details of its skeletal parts are well known ; 

 the mechanism of the stinging apparatus, however, has not been 

 fully understood, and none of the various attempts to explain how 

 the bee stings is based on a correct dissection of the musculature. 

 The sting of the bee is morphologically the ovipositor, but by both 

 the worker and the queen it is used exclusively for purposes of 

 stinging. Though structurally the organ has been but little modified 

 to adapt it to its secondary use, it is effectively disqualified for 

 egg-laying purposes through the obstruction of the channel of the 

 shaft by a pair of valvular lobes arising from the first valvulae that 

 serve for driving the poison liquid through it. 



The principal feature that endows the bees and other stinging 

 Hymenoptera with their stinging properties is the conversion of one 

 of the accessory glands of the female genital system into a poison- 

 secreting organ. The duct of this gland, which appears to be the 

 right gland of a pair of accessory glands, opens into a large sac 

 (fig. 41, PsnSc) that discharges directly into the proximal end of 

 the channel of the sting. The other, much smaller, tubular gland 

 (BGl), generally known as the "alkaline gland", lies to the left of 

 the poison sac. The experiments of Carlet (1890), which seemed 

 to show that it is only the mixture of the secretions from both glands 

 that has maximum toxic qualities, are not generally accepted as con- 

 clusive, and Trojan (1930) has recently shown that in the honey 

 bee the two glands do not open together, nor even at points where 

 their products could readily mix. The alkaline gland opens ventrally 

 in the membrane between the rami of the valvulae just before the 

 base of the shaft of the sting, and entirely outside the channel of the 

 latter. Nothing definite is known concerning the function of the 

 alkaline gland, but it has been supposed that its secretion in the bee 

 serves to lubricate the sliding parts of the sting, or to neutralize the 

 acid secretion of the other gland when the bee has failed in an attempt 



