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points the conditions determining its natural history may be of 

 such a nature that a slight and perfectly practicable modification 

 will destroy the species. 



In the history of mosquito control the value and the necessity 

 for a thorough study of the natural history of the different 

 species has been well illustrated. Save for the investigation 

 of certain naturalists, who were induced to study mosquitoes 

 by a general thirst for the knowledge of living things as an end 

 in itself, no studies of the natural history of mosquitoes were 

 made until a very strong suspicion of their connection with the 

 carriage of diseases had developed. Before this time arrived, 

 however, entirely from the standpoint of the naturalist, many 

 kinds had been named and the natural history and the structure 

 of the house mosquito had been given with a great wealth of 

 detail. 



The notion that mosquitoes had something to do with the 

 prevalence of malaria dates back to prehistoric times, reference 

 of that sort being found in early Indian literature. 



As early as 1848 it was clearly stated by a scientific man that 

 both malaria and yellow fever were probably transmitted by 

 insects. By 1898 Ross had completely determined the life history 

 of the malarial organism in birds and its transmission by mos- 

 quitoes. In 1898, Grassi determined that human malaria was 

 transmitted by mosquitoes of the genus Anopheles. In 1904, an 

 experiment of a most conclusive and striking nature was per- 

 formed by members of the London School of Tropical Medicine. 

 Two physicians, Sambon and Low by name, constructed a small 

 five-room house in one of the most malarial districts of the 

 Roman Campagna. The nature of the experiment and the 

 results of it are best set forth in Dr. Howard's words, as follows : 



"The experimenters, together with a Signor Terzi and two 

 Italian servants, lived in this house through the period when 

 malaria is most prevalent. They took no quinine and no health 

 precautions beyond the fact that at sundown each day they en- 

 tered the house and remained there until daylight the next morn- 

 ing. Dr. Rees, of the London School, visited them and occupied 

 the house with them for a portion of the time, and all three con- 



