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FUNDAMENTALS OF AGRICULTURE. 



Mosquitoes. These insects rank among our most 

 injurious ones, owing to their being the only means for 

 the transmission of malaria and yellow fever. In the 

 case of the former disease it has been estimated that 



BACTERIA LEFT BY FLY PASSING OVER GELATINE PLATE. 

 (Permission of Doubleday, Page & Co.) 



the losses which the malarial mosquitoes cause, in the 

 United States, amounts to not less than one hundred 

 million dollars a year. The mosquitoes which carry 

 malaria usually can be distinguished from the non- 

 disease carrying forms by their spotted wings, and by 

 their standing with their bodies at an angle to the sur- 

 face upon which they may rest, rather than nearly par- 



