OF THE CULEX MOSQUITO. 99 



in their anterior legs immediately below the coxo-tibial arti- 

 culation. These organs are composed of a fossa on each 

 side, or of two, more or less capacious, cavities (auditory 

 capsules) with orifices opening forwards ; and each having on 

 the inner side an elongated oval tympanum ; and the two 

 tympana are in close contact with a dilatation of the large 

 tracheal tube of the leg, whose upper extremity is in con- 

 nexion with an acoustic nerve which derives iis origin from 

 the first thoracic ganglion. A neighbouring portion of the 

 tracheal system he supposes to serve the purpose of a Eus- 

 tachian tube. 



And finally, J. Miiller, as quoted l)y Carus,* regards as 

 organs of hearing " two depressions or pits, in Gryllus 

 hieroglyphicus^ situated, one on each side, of the metathorax, 

 on the dorsal aspect, above the attachment of the last pair of 

 legs upon and closed by a delicate membrane, behind which 

 there exists a vesicle, filled with liquid, which receives a nerve 

 from the third thoracic ganglion." 



While bearing in mind the difference between feeling a 

 noise and perceiving a sonorous vibration, we may safely assume 

 with Carus — for a very great number of insects, at least — that 

 whenever true auditory organs are developed in them, their 

 seat is to be found in the neighbourhood of the antennae. 

 That these parts themselves are, in some instances, concerned 

 in collecting and transmitting sonorous vibrations, we hold as 

 established by the observations we have made particularly 

 upon Culex mosquito; while, we believe, as Newport has as- 

 serted in general terms, that they serve also as tactile organs. 



The male mosc(uito differs considerably, as is well known, from 

 the female; his body being smaller and of a darker colour, and 

 his head furnished with antennce and palpi in a state of greater 

 development. (Plate VI.. fig. 1.) Notwithstanding the fitness 

 of his organs for predatory purposes he is timid, seldom enter- 

 ing dwellings or annoying man, but restricts himself to damp 

 and foul places, especially sinks and privies. The female, on 

 the other hand, gives greater extension to her flight, and, attack- 

 ing our race, is the occasion of no inconsiderable disturbance 

 and vexation during the summer and autumn months. 



The head of the male mosquito, about 0-67 mm. wide, is 

 provided with lunate eyes, between which in front superiorly 

 are found two pyriform capsules nearly touching each other, 

 and having implanted into them the very remarkable anten7i(B. 



The capsule, measuring about 0-21 mm., is composed of a 

 horny substance, and is attached posteriorly by its pedicle, 

 while anteriorly it rests upon a horny ring, united with its 



* Loc. cit, 



II 2 



