Auditory Apparatus of the Culex mosquito. 363 
outward in every direction, enter the capsular space, and are 
lodged there for more than half their length in sw/ci wrought in 
the inner wall or cup of the capsule. 
“Inthe female the disposition of parts is observed to be nearly 
the same, excepting that the capsule is smaller, and that the 
last distal antennal joint is rudimental. 
“The proboscis does not differ materially in the two sexes ; 
but the palpi, although consisting in both instances of the same 
number of pieces, are very unlike. In the female they are ex- 
tremely short, but in the male attain the length of 2°73 millims., 
while the proboscis measures but 2°16 millims. They are curved 
upward at the extremity. 
“.... The position of the capsules strikes us as extremely 
favourable for the performance of the function which we assign 
to them; besides which there present themselves in the same 
light the anatomical arrangement of the capsules, the dispo- 
sition and lodgment of the nerves, the fitness of the expanded 
whorls for receiving, and of the jointed antennz fixed by the 
immovable basal jomt for transmitting vibrations created by 
sonorous undulations. The intracapsular fluid is impressed by 
the shock, the expanded nerve appreciates the effect of the 
sound by the quantity of the impression, of the pitch or qua- 
lity by the consonance of particular whorls of stiff hairs accord- 
ing to their lengths, and of the direction in which the undula- 
tions travel by the manner in which they strike upon the 
antenne or may be made to meet either antenna in consequence 
of an opposite movement of that part. 
“That the male should be endowed with superior acuteness 
of the sense of hearing appears from the fact that he must seek 
the female for sexual union either in the dim twilight or in the 
dark night, when nothing but her sharp humming noise can 
serve him as a guide. The necessity for an equal perfection of 
hearing does not exist in the female; and accordingly we find 
that the organs of the one attain a development which the 
other’s never reach. In these views we believe ourselves to be 
borne out by direct experiment, in connexion with which we may 
allude to the greater difficulty of catching the male mosquito. 
“In the course of our observations we have arrived at the 
conclusion that the antenne serve to a considerable extent as 
organs of touch in the female; for the palpi are extremely 
short, while the antenne are very movable and nearly equal 
the proboscis in length. In the male, however, the length 
and perfect development of the palpi would lead us to look for 
the seat of the tactile sense elsewhere; and in fact we find the 
two apical antennal joints to be long, movable, and compara- 
