584 AUDITORY APPARATUS OF THE MOSQUITO. 
I cemented a live male mosquito With shellac to a glass slide 
and brought to bear on various fibrils a th objective. I then 
sounded successively, near the stage of the microscope, a series of 
tuning-forks with the openings of their resonant boxes turned 
toward the fibrils. On my first trials with an Ut, fork, of 512 ¥. 
per sec., I was delighted with the results of the experiments, for! 
saw certain of the fibrils enter into vigorous vibration, while others 
remained comparatively at rest. 
he table of experiments which I have given is ch 
of all of the many series which I have made. In the first colu 
(A) I have given the notes of the forks in the French notation, 
which König stamps upon his forks. In the second (B) are the 
amplitudes of the vibrations of the end of the fibril in divisions 
of the micrometer scale; and in column (C) are the values 
these divisions in fractions of a millimetre. 
4° 
A. B. 3; 
Ut, ‘5 div 0042 mm 
Ut, 2:5 0200 
Mi, 1:75 ‘0147 
Sol, 2-0 -0168 
Ut, 6-0 0504 
Sol, 1:5 0126 
Bè- 1-5 0126 
Ut; 2-0 0168 
fork on the fibril 
pserved ampli- 
in the inten- 
put vibrated 
The superior effect of the vibrations of the Ut, 
is marked, but thinking that the differences in the 0 
tudes of the vibrations might be owing to differences 
sities of the various sounds, I repeated the experiment, 
with lower intensities the forks which gave the greater 
equality of amplitude, yet the fibre gave the a 
was tuned to unison with Ut, or to some other note vie 
tone of it. The differences of amplitude given by he inter- 
and Mi, are considerable, and the table also brings out the 1 
esting observation that the lower (Ut;) and the higher prt 
monics of Ut, cause greater amplitudes of vibration th pie 
intermediate notes. As long as a universal method for pe itch 
mination of the relative intensities of sounds of ai P 
remains undiscovered, so long will the science of acoustics 
