186 BEES AND BEE-KEEPING. 



forcibly dragged from its position up to S. The 

 darts are terminated by ten barbs, of ugly form (D, 

 Plate VI.), and much larger than those of the sheath, 

 and, so soon as the latter has established a hold, first 

 one dart, and then the other are driven forward by 

 successive blows. These, in turn, are followed by 

 the sheath, when the darts again more deeply 

 plunge, until the murderous little tool is buried to 

 the hilt. But these movements are the result of a 

 muscular apparatus yet to be examined, and which 

 has been dissected away to bring the rigid pieces 

 into view. The dovetail guides of the sheath are 

 continued far above its bulbous portion, as we see by 

 E, Plate VII. ; and, along with these, the darts are 

 also prolonged upwards, still held to the guides by 

 the grooved arrangement before explained ; but both 

 guides and darts, in the upper part of their length, 

 curve from each other, somewhat like the arms 

 of a Y, to the points c, c (A, Plate VI.), where the 

 darts make attachment to two levers [i, i'). The 

 levers {k, I, and k', V) are provided with broad 

 muscles, which terminate by attachment to the lower 

 segments of the abdomen. These, by contraction, 

 revolve the levers aforesaid round the points f, f, so 

 that, without relative movement of rod and groove, 

 the points c, c approach each other. The arms of 

 the Y straighten and shorten, so that the sheath and 

 darts are driven from their hiding place together, 

 and the thrust is made by which the sheath produces 

 its incision and fixture. The sides being symmetrical, 

 we may, for simplicity sake, concentrate our attention 

 on one, say the left in the Figure. A muscular con- 



