108 ENTOMOLOGY FOR MEDICAL OFFICERS 



The larva, which may be found in any sort of water in 

 and near human habitations, even in sewage, has a long 

 slender breathing-tube, which is about two and a half times 

 the length and twice the breadth of the slender, pointed 

 tracheal gills. The shaft of the antenna is broader in its 

 proximal two-thirds than in its distal third ; the broader 

 proximal portion is sparsely covered with microscopic spinules 

 and carries distally a fan-like tuft of about twenty long 

 branching hairs ; the slenderer distal portion has numerous 

 terminal hairs ; the terminal segment of the antenna is 

 minute and truncated. On either side of the 8th abdominal 

 segment are three rather irregular rows of scales, which are 

 rather numerous and stand in Echelon. 



Apart from its practical importance, Culex fatigans has a 

 peculiar interest as being the living document of two dis- 

 coveries of the first magnitude in the history of medicine, 

 namely. Sir Patrick Hanson's discovery {Journal of the Linnean 

 Society, " Zoology," 1 879) of the part played by mosquitoes 

 in the life-cycle of certain filarial blood-parasites, and Sir 

 Ronald Ross's Alscovery {Indian Medical Gazette, 1898 and 

 1899) of the necessary connection between mosquitoes and 

 certain Protozoon blood-parasites. The first discovery laid 

 open a new world to Pathology ; the second, which is 

 the outcome of the first, will affect the destiny of the 

 human race. 



Stegomyia, Theobald (Gr. o-Te'yo? = a house; /j.via = a. fly). 



Head and scutellum covered with overlapping squames 

 which on the scutellum are usually snow-white ; usually some 

 darts on the posterior part of the head. Palpi long in the 

 male, very short in the female. Clypeus scaly. Smallish, 

 black mosquitoes with bright (usually snow-white) markings 

 on head and thorax, and generally with bright white cross- 

 bands on abdomen and legs ; common in tropical and sub- 

 tropical latitudes all round the globe. Some of the best 

 known species are thoroughly domestic in habits, living in 

 human habitations, biting freely by day as well as at night, 

 and laying their eggs in anything that happens to contain 

 water. The eggs, so far as they are known, are dark — almost 



