THE HEAD OF THE BEE AND ITS APPENDAGES. 41 



the two, since all the work of the mandible falls upon it, the extensor 

 being used simply to open the jiiw. While these muscles h.a.ve their 

 origins on the walls of the head, they are not inserted directly upon 

 the .mandibles, but on large apodemes (fig. 13 A, EAp and BAp) 

 attached to the edges of the mandible. 



A gland opens at the inner margin of each mandible between the 

 anterior articulation and the base of' the apodeme of the flexor 

 muscle (fig. 13 A and B, IMdGl). In the worker it consists of a 

 large sac covered with secreting cells lying within the front part of 

 the head between the clypeus and the compound eye (fig. 10 A, 

 IMdGl). These mandibular glands may be most easily studied by 

 removing the front as shown in figure 10 A, B, and C. In order to 

 do this, pull the head from the thorax and allow the prothoracic legs, 

 which will usually come off with the head, to remain attached to it. 

 Next melt a small hole in the bottom of a paraffin dish with a heated 

 needle and fasten the head face upward into this, the attached legs 

 helping to anchor the head in the paraffin. Cover the specimen with 

 weak alcohol and by means of sharp needles remove the part of the 

 front on either side between the clypeus and the lower half of the 

 compound eye in the worker and drone and the entire front of the 

 queen. In figure 10 the whole front is removed in all three forms in 

 order to expose other internal parts of the head. 



The mandibular gland {IMdGl) is of greatest size in the queen 

 (fig. 10 B) , though it is large in the worker (fig. 10 A and fig. 13 A) , 

 but it is reduced in the drone (fig. 13 B) to a very small oval sac, 

 Avhich is hidden by another gland {SGI) in front (fig. 10 C) . It was 

 first described by Wolff (1875) as an olfactory mucous gland {Riech- 

 SGhleimdrlisse) and was supposed by him to secrete a liquid which 

 was poured upon the roof of the mouth in order to keep this surface, 

 on which Wolff thought the olfactory organs were located, in a moist 

 condition capable of absorbing odor particles. There is absolutely 

 no evidence, however, of the presence of organs of smell in the mouth, 

 and furthermore, as pointed out by Schiemenz (1883), the gland 

 varies in the three forms of the honey bee according to the size of the 

 mandible, which is proportionately largest in the queen and smallest 

 in the drone. Of the three, we should expect the drone or the worker 

 to have the sense of smell most highly developed, and hence, even if 

 we did not know that the sense of smell is located in the antenna3, 

 it would seem more reasonable to suppose that the glands of the 

 mandibles are connected in some way with the functions of these 

 organs themselves. 



The mandibles, as already stated, are used for eating pollen and as 

 tools for manipulating and modeling wax. Therefore, according to 

 Arnhart (1906), since the queen does not eat raw pollen, the product 



