21Q THE TICTORIAX NATURALIST. [Tol. XXIIl. 



THE MOSQUITO. 



£y ] . A. Leach, M.Sc, Organizing Inspector of Nature- 

 study, Education Defartment, Victoria. 



Owing to the unfortunate recall to Melbourne of the 

 Director of Education, it was necessar}- to substitute, at 

 shoTt notice, a lecture for Saturday. A lecture, illus- 

 trated by lantern views and living larvae and pup^, was 

 therefore given by Mr. Leach on the Mosquito. 



As the mosquito has been shown to be a necessary agent 

 in the spread of such dangerous diseases as malarial and 

 yellow fever, as well as of filariasis, and pos^ribly of 

 dengue fever, this small creature is attracting an amount 

 of notice quite disproportionate to its size. 



The name mosquito, derived through the Portuguese 

 from Lat. musca, causes some slight confusion. In 

 Brazil, the animal we know as the sandfly is the mosquito, 

 while in England the mosquito is called the gnat. The 

 difference between gnats and mosquitoes seems to be, in 

 fact, entirely one of temperature. In cold weather, the 

 animal does not suck blood, and so it is a " gnat." But, 

 with increasing temperature, she seems to develop a thirst 

 which can only be appeased by blood-sucking. Thus the 

 gnat of cold weather is identical with the mosquito of 

 warmer weather. But there is not likely to be any con- 

 fusion in Victoria about the identity of the animal, for 

 you all know her well. 



By means of lantern views, mostly photos, taken with 

 the help of the miscroscope by Mrs. F. Stone, of Mel- 

 bourne, the structure of the insect and its wonderful set 

 of bloodsucking implements was shown. 



These blood-sucking implements are things of wonder 

 and of beauty, for, just as there is a beauty of form and 

 colour, so there is also a beauty of adaptation to function, 

 and these interesting mouth-parts are perfectly adapted 

 for their unpleasant work. 



The mosquito was seen to be a typical insect divided 

 ■clearly into the usual parts — head, thorax, and abdomen. 



The abdomen, concerned with digestion and egg-pro- 

 duction, has no appendages. 



The thorax is concerned with locomotion, which is 

 effected in two ways. First, the animal walks by the 

 aid of its six jointed legs. Then, it flies with the help 

 of its one pair of wings, the second pair, as in the house- 

 fly, being reduced to mere knobs. These, possibly, serve 

 as sense-organs, and assist the animal in maintaining its 

 ".balance. Hence, they are called balancers. 



