THE STING OF THE HONEY-BEE. 



637 



seen in the figure. When in the natural position these projections lie 

 within the "sheath" {!>). These are known as the stop-valves. The 

 tubes of the lancets terminate just back of where the stop-valves are 

 attached, here opening into the cylindrical portion of the " sheath." 



Fig 2 



We pass now from the lancets to the "sheath" (Fig. 1, D), The 

 general shape is well shown in the figure. The cylindrical portion (Z>) 

 suddenly contracts, forming a shoulder at d, and a slender portion ex- 

 tends for some distance beyond. Along the straight edge the lancets 



