A. M. Mayer—Researches in Acoustics. 89 
founds his hypothesis on the supposition that the rods of Corti, 
in the ductus cochlearis, are bodies which co-vibrate to simple 
vibrations of the composite wave fall upon the membrane placed 
near the reed as they fall upon the membrane of the tympa- 
num; and these vibrations are sent through the stretched fibers, 
(or delicate splints of rye-straw, which I have sometimes used,) 
rom the membrane to the tuned forks, as they are sent from the 
membrana tympani through the ossicles and fluids of the ear to 
the rods of Corti. The composite vibration is decomposed into 
its vibratory elements by the co-vibration of those forks whose 
vibratory periods exist as elements of the composite wave 
motion; so the composite sound is decomposed into its sonorous 
elements by the co-vibrations of the rods of Corti, which are 
placing the forks in line and in order of ascending pitch, and 
attaching to each fork a sharply-pointed steel filament. If the 
arm be now stretched near the forks, so that the points of the 
filaments nearly touch it at points along its length, then any 
fork will indicate its co-vibration by the fact of its pricking the 
skin of the arm, and the localization of this pricking will tell 
us which of the series of forks entered into vibration. e 
rods of Corti shake the nerve filaments attached to them, and 
thus specialize the position in the musical scale of the elements 
of a composite sonorous vibration. Thus a complete analogy 
is brought into view between our experiment and Helmholtz’s 
comprehensive hypothesis of the mode of audition. 
3. Experiments on the supposed Auditory Apparatus of the Culex 
Mosquito. 
* For discussions of the vibratory phenomena of loaded strings, see Donkin’s 
cousties, p. 139; and Helmholtz’s Tonempfindungen, p. 267. me 
tha a4: ‘ ae } v . ry 
dissonance rests solely on a minute analysis of the sensations of the ear. 
This analysis could have ects made by any cultivated ear, without the aid of 
