A. M. Mayer— Researches in Acoustics. 97 
To subject to a severe test the supposition I now entertained, 
that the fibrils were tuned to various periods of vibration, I 
measured with great care the lengths and diameters of two 
fibrils, one of which vibrated strongly to Ut,, the other as 
powerfully to Ut,; and from these measures | constructed in 
homogeneous pine wood two gigantic models of the fibrils; the 
ril, and hence the direction of the pulses in the wave are in 
the direction of the fibril’s length, the latter cannot be set in 
vibration ; but if the vibrations in the wave are brought more 
and more to bear athwart the fibril it will vibrate with ampli- 
them to an auditory capsule, or rudimentary labyrinth, then 
these insects must cr ! 
direction sound more highly developed than in any other class 
of animals : 
