158 THB bke-kbBpkr'S guide ; 



that there are eight or ten barbs instead of one. Five of the 

 barbs are large and strong. These barbs catch hold and cause 

 the extraction of the sting when the organ is used. Near the 

 base of each lancet is a beautiful valvular organ (Fig. 74, E, E). 

 Mr. Hyatt thought these acted like a hydraulic ram, and by 

 suddenly stopping the current forced the poison through the 

 hollow lancets. It seetqs more probable that the view of Mr. 

 T. G. Bryant (Hardwick's Science Gossip, 187S) is the more 

 correct one. He suggests that these are really suction-valves — 

 pistons, so to speak — which, as the piston-rods — the lancets — 

 push out, suck the poison from the sacs. Carlet shows that the 

 poison-sac is not muscular, so the pumping is necessary. The 

 hollow inside each lancet (Fig. 74, l, I), unlike that of the awl, 

 is useful. It opens anteriorly in front of the first six barbs 

 (Fig. 74, o, ol, as shown by Mr. Hyatt, and posteriorly just 

 back of the valves into the central tube (Fig. 74, N), and 

 through it into the reservoir (Fig. 74, S). The poison then can 

 pass either through the hollow lancets (Fig. 74, /, /) or through 

 the central tubes (Fig. 74, I^), between the three spears. 



The lancets are held to the central piece by projections 

 (Fig. 74, T, T) from the latter, which fit into corresponding 

 grooves (Fig. 74, T) of the lancets. In the figure the lancets 

 are moved one side to show the barbs and valves ; normally 

 they are held close together, and thus form the tube (Fig. 

 74, N, Fig. 44, St.) 



At the base of the central awl two flexible arms (Fig. 7S, b^b) 

 run out and up, where they articulate with strong levers (Fig. 75, 

 D, D). The two lancets are singularly curve(d and closely 

 joined to the flexible arms by the same kind of dovetailed 

 groove and projection already described. These lancets con- 

 nect at their ends (Fig. 75, c, c) with heavy triangular levers 

 (Fig. 75, B, B), and these in turn with both Cand /? at/ and j. 

 All of these levers, which also serve as fulcra (Fig. 75, B, C 

 and D), are very broad, and so give great space for muscular 

 attachment (Fig. 75, m). These muscles, by action, serve to 

 compress the poison-sac, also cause the lever (Fig. 75, B) to 

 rotate about 5 as a center, and thus the whole sting is thrown 

 out something as a knee-joint works, and later the lancets are 

 pushed alternately further into the wound, till stopped by the 



