INSECTS AND HUMAN DISEASE 97 



their fill of healthy blood and did no harm; although 

 it does not require the imagination of a Jules Verne to 

 conceive that they caused their quota of annoyance, as any- 

 one who has ever provided a meal for even one hungry 

 mosquito will readily believe. Others, perchance, alighted 

 on someone harbouring blood parasites of malaria, some 

 traveller, maybe, who had contracted the disease in the 

 country and returned to the town to be nursed back to 

 health and strength. Woe betide the individuals who later 

 on fell victims to the " bites " of the latter insects, for, after 

 a developmental period, each mosquito would spread infec- 

 tion at every stab of its lancet-like mouth parts. All this 

 is history now; for with the reclamation of the Potomac 

 Flats, Washington, figuratively speaking, shook itself free 

 from the disease. 



Before proceeding to the study of the malaria mosquito, 

 let us make a few observations on the breeding habits of 

 mosquitoes in general. Certain mosquitoes may be aptly 

 termed pool mosquitoes ; these are the individuals respon- 

 sible for the spread of malaria. They breed in ditches 

 filled with herbage, in muddy, slime-covered water-holes, in 

 abandoned clay pits, which become waterlogged in winter, 

 and other similar situations, as often as not in the neigh- 

 bourhood of villages. Other mosquitoes breed in marshes 

 of larger area, and they, as befits their more lofty tastes 

 with regard to their breeding places, are relatively large 

 mosquitoes ; they are named Mansonoides, after Sir Patrick 

 Manson. Other mosquitoes, again, like brackish water, 

 and seek their breeding places in crab-holes and similar 

 situations: these, too, are annoying, but the majority are 

 harmless, as far as disease-carrying is concerned. The 

 only other mosquitoes which we need mention breed in 

 domestic utensils such as rain-water tubs, cisterns, old cans 

 in which rain water has collected, and broken bottles any- 

 where, in fact, where even a temporary puddle can be 

 found (Plate III.). As may be surmised, these mosquitoes 



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