592 AUDITORY APPARATUS OF THE MOSQUITO. 
the anatomical arrangement of the capsules, the disposition and 
lodgment of the nerves, the fitness of the expanded whorls for 
receiving, and of the jointed antennz fixed by the immovable 
basal joint for transmitting, vibrations created by the sonorous 
undulations. The intra-capsular 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 quality by the con- 
sonance of particular whorls of stiff hairs, according to their 
lengths; and of the direction in which the undulations travel, by 
the manner in which they strike upon the antenna, or may 
made to meet either antenne in consequence of an opposite move 
ment 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 others never reach. 
In these views we believe ourselves to be borne out by direct © 
periment, in connection 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 coh 
elusion, that the antenn serve to a considerable extent as ier 
of touch in the female; for the palpi are extremely short, W», 
the antennz are very movable, and nearly equal the 
‘ rfect develop- 
in length. In the male, however, the length and pe da 
ment of the palpi would lead us to look for the seat of hem 
sense elsewhere, and, in fact, we find the two apical am pairs; 
joints to be long, movable, and comparatively free from more 
and the relative motion of the remaining joints very much 
limited.” 
My experiments on the mosquito began late in the fall, and 
therefore I was not able to extend them to other ime Le 
spring I purpose to resume the research, and will a” a 
pecially on those orthoptera and hemiptera which volunta y = 
distinct and characteristic sounds. 
