THE MOSQUITO. 103 



lakes, they are apparently double brooded ; the first brood 

 appearing in July and the second in August.^ During the 

 hot weather of July and August the mosquitoes are most 

 numerous, and more annoying than during the cooler 

 weather. The life duration of the mosquito in the imago 

 state lasts about one week. A few individuals of the last 

 brood hibernate over the winter. The food of the mos- 

 quito, besides blood of human beings and animals, con- 

 sists of the sweets of flowers and other vegetable juices. 

 (I have often taken mosquitoes with a mixture of molasses 

 and rum used as a bait for capturing moths at night.) 



Mouth Parts. 



In this inquiry it is necessary to treat at some length 

 the disposition and arrangement of tlie mouth parts, the 

 contents and structure of the poison glands, which together 

 constitute the offensive and injurious portion of the mos- 

 quito. 



The mouth parts of Culex have received the careful 

 study of many observers, who vary considerably in their 

 results and give different enumerations of this compli- 

 cated mechanism. From Dimmock (Anat. of the Mouth 

 Parts, etc., of Diptera, pages 9-22, pi., 1881), the latest 

 writer on this subject, I extract the descriptions (with some 

 condensation) essential for the purpose of this paper. I 

 have further restricted these extracts to the mouth parts of 

 the female Culex, as it seems as yet doubtful whether the 

 male mosquito possesses the sanguinary tastes of its trucu- 

 lent companion. The difference that obtains in the mouth 

 parts of the male and female is chiefly comprehended in 

 the absence from the former of tlie mandibles, and the 



1 Eoss, Append. Second Arct. Voy., page Ixxvi. 



