40 



THE ANATOMY OF THE HONEY BEE. 



KMcl 



shows tlie ajipearance of the left mandible in side view, while the 

 right one is shoAvn detached from the head in figure 13 A. The 

 mandibles differ consjiicuously in size and shape in the three forms 

 of the bee as already described and as shown in figure 10 A, B, and C. 

 That of the worker is hollowed out somewhat on the distal half of 

 its inner face (fig. 13 A, Md) forming a spoon-shaped organ, the 

 edge of which is smooth and rounded. The mandibles of both the 

 queen (fig. 10 B) and the drone (C), however, are pointed at the 

 apex and have a conspicuous subapical notch. Those of the drone 



are smaller than those of 

 either form of the female, 

 but appear to be especially 

 small on account of the 

 great size of the drone's 

 head. The mandible of the 

 worker is undoubtedly to 

 be regarded as the special- 

 ized form, since the notched 

 mandible of the drone and 

 queen is of the ordinary 

 Hymenopteran type. Both 

 the drone and the queen 

 are, under normal circum- 

 stances, fed almost entirely 

 by the workers, and they 

 probably never have any 

 use for their jaws as feed- 

 ing organs. The queen 

 needs her large, sharp- 

 pointed mandibles for bit- 

 ing her way out of the 

 thick wax cell in which 

 she is reared, but the 

 drone, on the other hand, 

 being reared in an ordinary cell resembling that of a worker, except 

 in size, is easily able to cut through the thin cell cap with his com- 

 paratively weak jaws. The workers, however, have numerous uses 

 for their mandibles, such as biting through the cell caps, eating 

 pollen, and modeling wax. The last is the especial function of 

 the worker mandible, and probably it is to accommodate this jjur- 

 pose that it has acquired its specialized spoonlike shape. 



Each mandible is jnoved by two sets of muscles within the head. 

 The outer one constitutes the extensor muscle (fig. 13 A, EMd) and 

 the inner the flexor muscle (RMcl). The latter is the stronger of 



Fig. 13. — A, right mandible of worljer, anterior 

 view, witli extensor and flexor muscles (EAIrl 

 and Rilcl) and mandibular glands (IMdOl) at- 

 tached ; B, corresponding view of mandible of 

 drone, with muscles cut off a short distance from 

 their bases. 



