588 AUDITORY APPARATUS OF THE MOSQUITO. 
The auditory apparatus we have just described does not in the 
least confirm Helmholtz’s hypothesis of the functions of the organ 
of Corti; for the supposed power of that organ to decompose 480 
norous sensation depends upon the existence of an auditory nerve 
differentiated as highly as the co-vibrating apparatus, and in the 
case of the mosquito there is no known anatomical basis for sud 
an opinion. In other words, my researches show external €o- 
vibrating organs whose functions replace those of the tympanic 
membrane and chain of ossicles in receiving and transmitting 
vibrations; while Helmholtz’s discoveries point to the existence 
of internal co-vibrating organs which have no analogy to those of 
the mosquito, because the functions of the former are not to receive 
and transmit vibrations to the sensory apparatus of the ear, but 
to give the sensation of pitch and to decompose a composite 8 
norous sensation into its elements; and this they can only do by 
their connection with a nervous development whose parts are as 
numerous as those of the co-vibrating mechanism. Now as such 
a nervous organization does not exist in insects, it follows that 
neither anatomical nor functional relations exist between the co- 
vibrating fibrils on the antennz and the co-vibrating rods in the 
organ of Corti, and therefore, that neither Hensen’s experiments 
on the Mysis (assumed by Helmholtz to confirm his hypothesis), 
nor mine on the mosquito, can be adduced in support of Helmholtz’: 
hypothesis of audition.* 
The above described experiments were made 
think that I am authorized to hold the opinion that 
lished a physical connection existing between the sounds emi 
by the female and the co-vibrations of the antennal fibrillæ iation 
male mosquito; but only a well established physiological 7° . 
with care, and I 
I have estab: 
ciful and entirely devoid of reason; for the semicircular canals are fx geat 
ynamic relation to the ted ani c me embrane, aa receives the vibration i 
the inner ear. Really, we duced in 
the direction of a manā w the e difference in ie intensities of the anes enr and by te 
the two ears, and this determination is aided by the form of the pee en ve ; 
that man can turn his head around a vertical axis. Other he see 
have the power of facilitating the determination of motion by moving a 
outer ears ang rege n It is also a fact that when one depte 
that t sciou "e o affected always supposes 4 § sound to 
tide on which is his goo de s, it is not 
he organ of Corti having disappeared in the lower oe 
iikely that it would reappear in the articulata; and paii Corti is the PPF 
when we gme that the peculiar function of the organ constantly 
of tie als are 
ciation 
called upon to 
omposite sounds, whose signification mam 
