chief function, however, is to assist the act of ovipositing, and with 

 the aid of the sting palpi, the egg is guided from the vent down the 

 sting and into the cell. Nowhere is this action more faithfully or 

 clearly indicated than in Herrod-Hempsall's sudy of the subject, 

 and to whom tribute is due for this contribution to our greater 

 knowledge of the bee's anatomy. 



Under a high power microscope tiny pores forming sense organs 

 may be discerned in the shaft of the sting proper. 



(2) The Operating Mechanism. At the end of the sting furthest 

 from the tip, the sheath and the two lancets are together curved 

 upwards and outwards (see Fig. 3), and at their extremities they are 

 firmly secured to a number of rigid plates which act as levers and as 

 anchorages to the muscles (see Fig. 1). To these are attached the 

 various muscles which acting under the control of the nervous 

 system bring the whole structure into operation when required. 

 AU these several parts are neatly folded and packed into the confined 

 space of the sting chamber in the last abdominal segments. One 

 of the most advanced and complete descriptions of the sting mecha- 

 nism was given some years ago by that able and painstaking inves- 

 tigator, R. E. Snodgrass^, of the American Bureau of Entomology. 



The sting is manipulated as follows. First of all the tip of the 

 abdomen is bent down. Then, through the operation of the muscles, 

 a lever action on the base of the sheath moves it out of the sting 

 chamber and forward between the lancets enabling it to be inserted 

 a little way into the victim until the barbs at the tip hold it firmly. 

 The two lancets are then also projected down and entering the 

 puncture formed by the point of the sheath, make the hole a little 

 deeper. Their barbs in turn hold them secure while the sheath is 

 again driven forward, the lancets following suit in due course, and 

 being worked alternately. This action continues until the shaft is 

 buried right up to the pouch, a depth of penetration which is, in 

 fact, little more than one-twentieth part of an inch. All the time this 

 rapid movement has been in progress, venom is being pumped down 

 the main channel and diffuses into the wound through the various 

 openings in the tip. 



And here should be mentioned another point in the design of 

 the organ. A reference to Fig. 2A will show the intimate contact that 

 occurs between the lancets and sheath, and in view of the great 

 slenderness of the sting it would be exceedingly hable to buckle if 

 excessive friction were to be set up while sliding motion was occur- 

 ring over such a length. This difficulty also is ingeniously overcome 

 by the provision of a number of microscopically minute studs or 

 projections distributed along the length of the grooves or rails 

 uniting the lancets to the sheath and preventing too intimate a con- 

 tact. Furthermore, they act as distributing points for an oily liquid 

 from a special gland which is fed into the base of the three main 



°R. E. Snodgrass. The Bee World, Jan., 1933. 



