THE HEAD OF THE BEE AND ITS APPENDAGES. 47 



by the honey stomach (fig. 44, HS), which latter, as Cheshire re- 

 marks, could no more suck honey through the ajsophagus than a 

 balloon could suck gas from a pipe. The liquid undoubtedly runs 

 up the temporary tube between the blades of the mouth parts first 

 by capillary attraction, but it must be greatly assisted along its way 

 to the mouth by the retraction of the labium. The load brought up 

 when this is pulled back is then sucked into the mouth by the 

 pharynx while the labium immediately goes out again after more. 

 It acts thus as a sort of mechanical feeder and this function is prob- 

 ably derived from the lapping motion of the under lip in wasps and 

 hornets. 



The mentum (fig. 15 D and G, Jit) is hinged freely upon the 

 submentum (Smt), the latter, as already described, is set into the 

 socketlike angle of the lorum, while, finally, the arms of the lorum 

 are articulated to the distal ends of the cardines of the maxillae. 

 Now, when the labium is retracted by means of muscles attached to 

 the mentum, the submentum turns in the loral socket and assumes a 

 position at right angles to the mentum while the lorum itself turns 

 somewhat on its articulations with the cardines. This great freedom 

 of motion is permitted by the loose membrane of the fossa in which 

 both the maxillaj and the labium are suspended. 



The observer, however, can not fail to note that beside this motion 

 of the entire labium the tongue itself, or glossa (6-7.y), performs a 

 conspicuous independent movement of its own. It is by far the most 

 active member of the mouth parts during feeding, being activeh' 

 thrust out and retracted while its tip is constantly moved about in 

 a way suggestive of its being delicately perceptive of taste or touch 

 or perhaps to both of these senses. So great is the retractile power 

 of the tongue that its tip, which normally extends far beyond the end 

 segments of the labial palpi, can be drawn back entirely within the 

 latter. This contractile activity appears at first sight to be due to 

 elasticity, but a closer examination will show that the entire ligula, 

 i. e., the paragiossae (Pgl) as well as the glossa (Gls), moves back 

 and forth and that the action is due to a retraction of the base of the 

 ligula (fig. 15 F, Lg) into the anterior end of the mentum (Jit). 

 The ligula is supported on a membranous cone at the end of the 

 mentum whose walls are strengthened by three thin chitinous plates, 

 two above (F, p) and one below (D, g). By the contraction of 

 muscles situated within the mentum (fig. 16, IRMd) and inserted 

 upon the base of the ligula the latter is pulled into the end of this 

 cone whose walls, including the chitinous plates, simply turn inward. 



But the tongue does possess also a contractile power of its own by 

 means of which it actually shortens its length. A flexible rod arising 

 from the median ventral supporting plate (fig. 15 D, o) of the ligula 

 extends throughout its length. The base of this rod is curved down- 



