84 
ORGANS OF SOUND. 
The voice organs of insects have been studied by 
Swammerdam (158), Reaumur (139), Hunter (69), 
Charbrier, and Burmeister (17) ; but it is principally 
to Landois (88) and Marey (107), who carried out 
elaborate experiments, that we are most indebted for 
what we know. 
Charbrier, Burmeister, and Landois recognise three 
tones produced by bees : the first by the vibration 
of the wings ; the second, much sharper, by the 
vibrations of the abdominal rings ; and the third, 
the most acute and intense, by the action of a true 
vocal apparatus placed in the stigmatic orifice. 
Landois ( 88 ) described the tones due to the 
wing-beats. The wings produce a tone which 
depends upon the number of vibrations, varying 
from one individual to another according to the 
size of the wing. Landois found this wing- tone 
in the bee in vigorous flight to be 440 vibrations, 
up to a in the treble clef, and dropping to e, or 
330 vibrations, when fatigued. The queen and drone 
])rodiice different tones, owing to their wings being 
longer. 
Marey (107), in 1868, measured the wing-beats by 
the graphic method described on page 44, and found 
190, but such experiments are uncertain, owing to their 
great difficulty. When the vibrations are reduced to 
190 the tone produced is over an octave lower than 
the note a. 
The noise is not produced by the wings only, as 
a , simple experiment of Girard (48) proves this. If 
one of the large humble bees, such as Bovibus ter- 
