INSECTS: STINGS AND OVIPOSITORS 



149 



We need not be long in finding it. For "here, at the 

 base of the sheath, into which it enters by a narrow neck, 

 lies a transparent pear-shaped bag, its surface covered all 

 over, but especially toward the 

 neck, with small glands set 

 transversely. It is rounded 

 behind, where it is entered 

 by a very long and slender 

 membranous tube, which, after 

 many turns and windings, 

 gradually thickening and be- 

 coming more evidently glandu- 

 lar, terminates in a blind end. 



This is the apparatus for 

 preparing and ejecting a pow- 

 erful poison. The glandular 

 end of the slender tube is 

 the secreting organ: here the 

 venom is prepared; the re- 

 mainder of the tube is a duct 

 for conveying it to the bag, a 

 reservoir in which it is stored 

 for the moment of use. By 

 means of the neck it is thrown 

 into the groove at the mo- 

 ment the sting is projected, 

 the same muscles, probably, 

 that dart forward the weapon 

 compressing the poison- bag 

 and causing it to pour forth its contents into the groove, 

 whence it passes on between the two spears into the 

 wound which they have made. 



STING OF BEE. 



a, Tip of Lancet, more enlarged. 



