LIFE HISTORY AND SEASONAL PREVALENCE 145 



every available pool, and soon strange Culiciform larvas, 

 with short breathing tubes will be found in the pools of 

 fairly clean rain water that form in every depression of the 

 ground. Before long C.fatigans, though still taking a con- 

 siderable share in the business of rendering human existence 

 less endurable, is thrown into the shade by numbers of 

 small Mosquitoes " brindled " with intensely contrasted 

 black and white, while the unobtrusive Anopheles, though 

 really present in large numbers are less importunate in 

 their attentions, and will not so readily be found by the 

 unpractised searcher. On this account, and because they 

 are more purely nocturnal than the Culices, those who do 

 not know where and when to look for them may be led to 

 report them as scarce or absent, though in reality they 

 may be present in large numbers. I suspect too that the 

 elevation of an upper storey affords a more secure haven 

 from their attacks than is the case with Ciilex. 



Mr. Aitken, in the paper already quoted, remarks : — 

 "As regards the mature Anopheles, the most remark- 

 able fact in my notes is that I have not seen one 

 during these last twelve months, excepting those that I 

 reared. This fact will give the best idea of what an insidious 

 -enemy we have to deal with. I lived most of the year at 

 the Bombay Club, within a stone's throw of the Frere 

 Fountain, in which Anopheles was being produced by the 

 thousand, but I never saw one, though I was often tormented 

 by Culex, the larvae of which were comparatively scarce. 

 Anopheles is a small, sHm Mosquito, of a pale, ashy-grey 

 colour, difficult to see at any time, and it appears to fly only 

 by night, so it is rarely seen. Add to this that its bite 

 appears to be almost painless, and you will see that one 

 may have malaria injected into him night after night while 

 he is sleeping without curtains, under the belief that there 

 are no Mosquitoes. I say that its bite is almost painless 

 on the authority of my own experiments only. I kept mine 

 in a bottle with thin musHn tied over the mouth, and if I 

 laid my arm on the muslin the females attacked me at once 

 and did not leave off till they were bloated with blood. I 

 sometimes felt a slight prick at the moment when they 

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