AUDITORY SENSE OP] HONEY-BEE 197 



adapted for this purpose, providing they had an external portion, 

 corresponding to the tympanum. 



The Johnston's organ, lying in the second antennal segment, 

 consists of the peculiarly modified articular membrane between 

 the second and third antennal segments and of many sense cells 

 whose fibers unite with pecuhar knobs extending inwardly from 

 the articular membrane. This organ does not seem well adapted 

 to act as an auditory organ unless it is able to receive sound 

 vibrations of a very low frequency. It might also be sensitive 

 to weak air currents and possibly to jars, but the most reasonable 

 function that. the writer can think of is that it may serve as a 

 statical organ to register the movements of the fiagellum. 



The pore plates, lying so abundantly on the antennae and called 

 olfactory organs by most of the other authors, were found to have 

 two grooves encircling each elhptical plate, thereby allowing the 

 plate to move in and out on a double hinge. Judging from this 

 mechanism, the pore plates might act as an air-pressure apparatus 

 to inform the bees of an object immediately in front of them, and 

 thus prevent them from striking against objects. They might also 

 be sensitive to the weak air currents made by workers fanning, 

 thereby serving as an apparatus to keep the bees constantly 

 informed whether or not the fanners are working properly. 



The functions of the Forel flasks and pit pegs are problematical. 



The chordotonal organs, found in the proximal ends of the 

 tibiae, are very compUcated in structure and are similar to those 

 found in the tibiae of crickets and katydids, but the former do 

 not have external membranes, while the latter do. Nothing can 

 be said about the function of the chordotonal organs in 

 honey-bees. 



A group of gangUon cells was found in the extreme distal end 

 of each tibia, but nothing can be said about its function. 



In conclusion, it may be that the sense of hearing in insects is 

 on no higher plane than that advocated by Forel C08), who 

 believes that insects do not hear, at least as we do, but compares 

 this perception in them to that in deaf-mutes who feel the roUing 

 of a carriage at a distance. Forel says: 



