THE MOSQUITO. 105 



tills appendage may be considered a rod or a tube, and, if 

 the latter, whether it is not a duct for the injection of 

 poison. He is in no doubt as to the actual eifusion of a 

 poisonous fluid, but, from tlie extreme delicacy of the 

 microscopic examination, is unable to reach a definite re- 

 sult as to whether the hypopharynx is its channel. The 

 later examinations (alluded to under "Poison Glands") of 

 Macloskie seem to place this trying question in a clearer, 

 if not certain, light. At any rate, the hypopharynx acts in 

 conjunction with the epipharynx as an instrument of suc- 

 tion, and both are complementary organs. 



The mandibles are the most delicate of the mouth parts 

 of Culex and are composed of "two very thin, linear lance- 

 olate lamellte of transparent chitin, which rest with their 

 inner edges beneath each half of the hypopharynx, their 

 outer edges projecting beyond its outer edge, on each 

 side." (Dimmock.) Dimmock describes them but does not 

 seem to have discovered their significance or suspected it. 



The maxillae are also lamellae of chitin serrated with 

 a minute corrugation, which varies in diflerent species in 

 its inclination to the strengthening chitin rod on the inner 

 side of the maxillfe. In some species it is at right angles, 

 in others obliquely inclined. At the extremity of the 

 maxillae is a row of papilla?, varying in their number 

 both in different species and different individuals. The 

 papilla have been regarded as serrations, by some ob- 

 servers. The maxillse are accompanied by the maxillary 

 palpi at their bases, which are four or five jointed flexible 

 and abbreviated stalks. Dimmock considers the office of 

 the maxillfe to be the drawing into the perforated skin of 

 the other mouth parts, but ]\Iacloskie expressly alludes 

 (Science, X., 106) to their cutting action as the actual or 



