§ II.] HEAD AND ORGANS OF SENS A TION. 93 



places, and the desired finish is given to the cells. This 

 organ has been denied by some to be a hollow tube, but 

 this is not the view generally held, and it certainly does 

 not act wholly by handing up the food, for there is a 

 furrow or gutter running along the whole length of its 

 under side. Thus, when a bee is imbibing honey the 

 rings of the abdomen have a vibratory motion similar to 

 pumping, showing to the casual observer that suction is 

 rapidly going on. Dr. Bevan tells us that the true 

 tongue is an extremely minute object at the base of the 

 maxillsej but this appears to have been a mistake of 

 his own. 



The labial palpi (Plate II. Fig. 3 0) rise from the base 

 of each side of this lapping instrument, and are also 

 ciliated exteriorly. They appear to serve as feelers to 

 the mouth. Between these and the tongue are the two 

 small sheaths or membranes called the paraglossae ; and 

 outside of the same are the working portions of the lower 

 jaw, or the maxillae (Fig. 3 n), which are also provided 

 with hairs and with two feelers midway known as maxil- 

 lary palpi. When the jaws close on the tongue they 

 form a sheath or defence thereto. 



With the mandibles of the upper jaw opening right 

 and left, and the maxilla of the lower, which serve to 

 hold the object laboured upon, the insect prepares its 

 work for the sweeping-up apparatus of the lower parts. 

 Thus, when combs become mouldy, or in any way unfit 

 receptacles for brood or honey, these tools provided by 



