THE NATURAL HISTORY OF BOMBAY MALARIA. 39o 



development, and produce the generation of sporozoits whereby the 

 continuation of the species might be secured. 



Besides solving a problem of the greatest interest to all natural- 

 ists, Ross' investigation supplied the answer to a riddle which had 

 baffled medical men for hundreds of years ; and what was still 

 more important, placed in the hands of the sanitarian a new 

 weapon by which he could attack the greatest scourge of human 

 existence in tropical and sub-tropical countries, with some hope of 

 success. For the discovery that anopheles mosquitoes became 

 infected with malaria by sucking the blood of sufferers from the 

 disease and that subsequently these infected mosquitoes became 

 capable by their bite of transmitting the parasite to healthy per- 

 sons, offered to all those who care to avail themselves of the know- 

 ledge, a certain method of escaping the disease by protecting 

 themselves from mosquitoes, and at the same time suggested a 

 protective measure of wider scope, the reduction or suppression of 

 anopheles mosquitoes, by the adoption of which whole communi- 

 ties may benefit. 



We may note that, malaria first became of interest to natural- 

 ists when Laveran, by his discovery of the malarial organism, 

 showed that the disease was caused by the action of a minute 

 animal parasite. Subsequently this interest was stimulated into 

 activity by Ross' remarkable demonstration of the part played by 

 mosquitoes in the transmission of this parasite from man to man 

 and the result has been the foundation of modern Tropical Sanitation, 

 which is largely based upon a knoMdedge of the natural history of 

 insect pests and animal parasites. 



In discussing the Natural History of Malaria the subject may be 

 approached from several different points of view. We can study 

 the malarial organism as a type of the minute animals called by 

 zoologists Sporozoa, a sub-class of the unicellular animals known as 

 Protozoa. Or we may take up another aspect of malaria and study 

 the anopheles mosquito, the alternative host of the parasite, which 

 is transmitted by its bite from man to man. 



It is with this latter aspect of malaria, particularly as it affects 



Bombay, that I am concerned at present ; but in a discussion of 



this subject I find myself considerably handicapped by having to 

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