172 ARTHROPODA. 



in the female. The queen never uses her sting except in com- 

 bat with other queens. 



Remove the dorsal integument of the abdomen of either a 

 fresh or preserved specimen, and find the dark brown shaft of 

 the sting, near the posterior end. Grasp the shaft with a pair 

 of fine forceps and forcibly remove it. A considerable mass of 

 tissue will be removed adhering to the base of the shaft, but this 

 consists for the most part of accessory organs that must be 

 understood. Spread the sting upon a slide, and either dehy- 

 drate and mount in balsam, or mount in glycerin. The balsam 

 mount will prove more satisfactory, but the cover must be 

 clamped down until the balsam hardens. 



1. The shaft consists of three parts: 



(a) A heavy support, called the awl or sheath, pointed at its 

 extremity and sending a pair of arms or arches from its base, 

 which normally bend ventrally, but are here forced to the sides. 

 At its extremity each of these arches enlarges to form a rather 

 large flattened plate, the sheath plate, to which strong muscles 

 are attached. 



(b) A pair of lancets which are fastened to the dorsal surface 

 of the sheath and the sheath arches by tongue and groove joints 

 (each tongue is enlarged along its inner margin so that it is held 

 firmly in the groove). Each lancet is pointed at its free extrem- 

 ity, and its sides near the point are set with barbs that point 

 toward the base of the sting. The arch of each lancet is con- 

 tinued past the end of the corresponding sheath arch, and is 

 there articulated to one corner of a somewhat triangular plate. 

 The remaining corners of each are articulated respectively to the 

 large sheath plate and to another plate, the oval plate. Deter- 

 mine the attachment of the muscles to the plates and find what 

 movements of the lancet the contraction of the different sets of 

 muscles would cause. You must understand that the lancets 

 are elastic and bend quite easily. 



The large muscles attached to the sheath plates were attached 

 to the wall of the abdomen and function to give the thrust that 

 sets the sting. After the sting is drawn from the body of the bee. 



