298 N. E. McINDOO 



MANDIBLES 



Janet ('lib) describes a sense organ in the mandible of the 

 honey bee which he thinks may have an olfactory function. To 

 ascertain this experimentally, the mandibles of 30 workers were 

 amputated close to the base. These bees appeared completely 

 normal and did not fight each other. They lived from 5 hours 

 to 15 days, with 7 days as an average. The average reaction 

 time to oil of peppermint was 2.6 seconds, to oil of thyme 3.3 

 seconds, to oil of wintergreen 4.6 seconds, to honey and comb 7.7 

 seconds, to pollen 6.2 seconds and to leaves and stems of penny- 

 royal 4.7 seconds. These give a general average of 4.8 seconds 

 whereas the average for the same odors with unmutilated bees 

 was 3.4 seconds. We may attribute this slight difference in 

 time either to the injury caused by the amputation, or to the 

 fact that the mandibles help to perceive odors or to both. The 

 bees tested were 20 in number. 



BUCCAL CAVITY 



Huber (1814) states that the seat of the organs of smell in the 

 honey bee is the buccal cavity, whereas Wolff (1875) discovered 

 some sense organs on the epipharynx of the same insect. The 

 epipharynx lies in the mouth cavity and forms a portion of its 

 roof. To determine whether this cavity has anything to do with 

 olfaction, Huber's experiment of filling the mouth cavity with 

 flour paste was repeated. With the aid of a small pencil brush 

 the mouth cavities of 25 workers were thus filled. When the 

 paste had become perfectly dry, the bees were put into observa- 

 tion cases. They seemed otherwise entirely normal and all tried 

 to eat candy although some were unable to move their probosces 

 on account of the hard paste. They lived from 2 hours to 16 

 days, with 7§ days as an average. However, by the end of the 

 fourth day the paste had come out of their mouths. The aver- 

 age reaction time to oil of peppermint was 2.55 seconds, to oil 

 of thyme 2.75 seconds, and to oil of wintergreen 2.75 seconds. 

 This gives a general average 2.68 seconds. The average for 



