44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



According to the law of capillarity the height to which a liquid rises, 

 in a tube varies inversely with the diameter of the tube. In other 

 words, the smaller the tube the higher a liquid rises in it. Using a 

 tube four times as long as the glossa and with the diameter equal to 

 that of the average diameter of the groove in the glossa, water would 

 rise to the top of the tube merely by capillary attraction. This demon- 

 strates that licfuids quickly pass through the groove, and the move- 

 ment of them is increased by the aid of the many pseudo-hairs (fig. 

 3 A, Hr 2 ) lining the groove and by some of them interlocking at the 

 extreme edges of the groove to exclude the outside air. These hairs 

 point toward the base of the tongue, making the groove as capable of 

 carrying liquids as a wick is of lifting oil from the bottom of a tall 

 bottle. 



At the proximal end of the groove the liquid is turned to either 

 side of the glossa by the fleshy tongue (fig. 8, Tri), and is prevented 

 from traveling further on the ventral side of the mentum by the 

 shoulder which is formed by the two chitinous processes (Pr) pro- 

 jecting below the ventral surface of the glossa. The shallow groove 

 (fig. 7, Gz\) on top of the tongue probably serves to hold the excess 

 of liquid when it has difficulty in following its proper course. 



As soon as saliva mixes with the food, a chemical or physical 

 change is effected, and this change perhaps liberates odors that were 

 not smelled by the bee before the food was eaten. Again, the saliva 

 might so affect the quinine in the food described on page 14 that the 

 faintest odor imaginable could be detected by the pores on the base 

 of the tongue, and also probably by those on the labial palpi and 

 maxillae. It must be remembered that while the liquids are passing 

 from the ventral side to the dorsal side of the tongue, and vice versa, 

 the paraglossae close around the tongue, making a perfect tube, and 

 the labial palpi close tightly against the paraglossae, and the maxillary 

 lobes are folded around all of these appendages. It is thus seen that 

 the olfactory pores on the glossa, labial palpi and maxillae are almost 

 against the liquid as it passes to the base of the mentum, for, as 

 already pointed out, the pores on the labial palpi and maxillae lie on 

 the inner surfaces of these appendages. 



This closes the description of the role played by capillary attraction 

 in carrying liquids from the tip of the tongue to the base of the 

 mentum. The entire process is clear to the writer except where the 

 saliva and liquid food pass around the base of the tongue. It is 

 strange that both liquids can travel in opposite directions along the 

 same route by no force other than capillarity. This is partially 



