AUDITORY SENSE OF HONEY-BEE 197 
adapted for this purpose, providing they had an external por tion, 
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 peculiar 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 flagellum. 
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 elliptical 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 complicated 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 ganglion 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 (’08), who 
beHeves that insects do not hear, at least as we do, but compares 
this perception in them to that in deaf-mutes who feel the rolling 
of a carriage at a distance. Forel says: 
