MOSQUITOES 147 



spotted wings and boat-shaped eggs undoubtedly be- 

 longed to the genus appropriately named Anopheles ; 

 and only the species of this genus, so far as we know, 

 are capable of conveying the infection from man to 

 man. In their bodies ohly will the gametocytes 

 develop. If swallowed by other biting insects or by 

 leeches, etc., they disintegrate, and are no more. 



The word mosquito has no scientific import ; 

 derived from the Spanish or Portuguese, it simply 

 means ' little fly ' ; it is used popularly to denote a 

 gnat which bites, and most gnats bite when they have 

 a chance. The word is sometimes extended to include 

 certain midges. The Dipterous family, Culicidae, to 

 which the gnat belongs, contains, according to Major 

 Giles, some 242 species, divided amongst 8 genera. 

 The great majority of species, some 160, however, 

 belong to the genus Culex ; Anopheles includes 30 ; 

 whilst the remainder are divided amongst the 

 other 6 genera, none of which are large. The 

 collections which have been made at the British 

 Museum, and which were worked out by Mr. 

 Theobald, contain many species of Anopheles new 

 to science ; so that we have now some half 

 hundred species of the genus 'which has been 

 hopelessly convicted of being the medium by which 

 the malaria parasite is transmitted from person 

 to person.' According to the last-named authority, 

 we have in England 17 species of Culex, and 2 of 

 Anopheles, A. bifurcatus and A. maculipennis {claviger), 

 though some authorities are inclined to add a third, 

 A. nigripes. Five other species, belonging to the 

 smaller genera of Culicidae, make a total of some 

 24 species of gnat or mosquito found in England. 

 Culex pipiens, probably the commonest gnat the wide 

 world over, conveys the parasite Proteosoma, or, as 

 Ross now calls it, Hcemamoeba relicta, of the avian 

 malaria from bird to bird ; but it will not carry the 



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