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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



base of the mandibles, and a few (fig. 2 N) on top of the head directly- 

 above the pharyngeal plate (fig. 10). The following figures repre- 

 sent the innervated hairs found in sections through the palpigers 

 (figs. 2 O, 7, Pig) ; on the side of the mentum (figs. 2 P, 7, c 15 ) ; on 

 the glossa (fig. 2 Q and R) ; on the lab rum (fig. 2 S and T) ; and on 

 the labial palpi and maxillae (fig. 2 U). 



In structure these various hairs are all alike in that they have thick 

 Avails, sharp points and distinct sockets. The sockets of the smaller 

 hairs usually lie slightly beneath the external surface of the chitin, 

 as shown in figure 2 D, while those of the larger hairs may lie a little 

 beneath the external surface of the chitin, as seen in figure 2 G, or 

 above the surface of the chitin, as shown in figure 2 Q. The chitin con- 

 necting the base of the hair with the socket is always more or less 



Fig. 3. — Cross-sections through glossa or tongue of a worker honey bee, 

 showing internal anatomy including groove (Gv), canal (Can) inside rod (R), 

 sense cells (SC), nerve (JVi), trachea (Tr) ; lumen (L), and bases of pseudo- 

 hairs (Hr 1 to Hr*) and innervated hairs (c w ), x 230. A, through middle and B 

 through tip of glossa. 



flexible, so that the least movement of the hair mechanically irritates 

 the end of the sense fiber. 



The sense cells belonging to all the hairs drawn were not seen, but 

 the sense fibers were seen as shown. A hair was never regarded a 

 sense organ unless a sense fiber was seen running into it. The sense 

 cells are always spindle-shaped and the sense fibers (fig. 2 H, SF) 

 never run far into the hairs. 



The hairs at the tip of the tongue of the honey bee (fig. 7, Gls) 

 have been regarded as gustatory in function, but as yet no one has 

 ever shown that they are innervated. In cross-sections through the 

 middle of the tongue the sense cells (fig. 2 Q, SC) are generally dis- 

 cernible, but owing to the poor fixation only traces of them may be 

 seen in the tip of the tongue, although the sense fibers (fig. 2 R, SF) 

 are usually visible. On either side of the tongue a nerve (fig. 2 Q, 

 N x ) and a trachea (Tr) are always present. They lie side by side 

 and are fastened together with connective tissue. Branches from 



