136 



Beekeeping 



The typical mandible of the 

 Hymenoptera is like those of 

 the queen and drone while the 

 worker mandible is a specialized 

 type. The fact that the worker 

 mandible is smooth and rounded 

 is often pointed out in connec- 

 tion with the fact that worker 

 bees cannot puncture fruit. It 

 need scarcely be said that queens 

 and drones never injure fruit. 

 The mandibles are moved by 

 two sets of muscles (Fig. 70, A, 

 EMcl and RMcl) with their origin 

 in the head. On each mandi- 

 ble is the opening of a gland 

 {IMdGl), located in the head 

 (Fig. 69, A, B ; Fig. 70, A, B), 

 which is a large sac in the 



worker (Fig. 70, A) but is reduced in the drone (Fig. 70, 



B). In the queen (Fig. 69, B) it reaches its greatest size. 



It was originally described by 



Wolff ^ as a mucous gland which 



serves to keep the surface of the 



roof of the mouth moist, where 



he thought the olfactory organs 



are located. The function of 



this gland is not clear, but it is 



supposed by Arnhart ^ to func- 

 tion in softening wax. This 



theory rests on the assumption ^jq 71 



Fig. 70. — A, right mandible 

 of worker with muscles and 

 mandibular gland (IMdGl) 

 attached ; B, corresponding 

 view of mandible of drone 

 with muscles cut off. 



2MdCI 



Internal mandibular 



made by Cheshire and others gland (BMdGl) of worker. 



1 Wolff, O. J. B., 1875. Das Riechorgan der Biene. Nova Acta der Ksl. 

 Leop.-Carol. Deutsch. Akad. der Naturf., XXXVIII, pp. 1-251. 



2 Arnhart, Ludwig, 1906. Anatomie und Physiologie der Honigbiene. 

 In AlfoDsus' "AUgemeines Lehrbuch der Bienenzucht," Wien. (99 pp., 

 4 pis., 53 figs.). 



