For many years we have known that malarial fever and certain similar animal diseases are caused by minute parasites of the blood. Considering the number of investigations on the etiology of these diseases, it certainly seemed strange to some that no light could be thrown on the form and mode in which the parasites, especially of human malaria, existed outside of the body, and on the way in which they gained entrance into our bodies. A number of theories were advanced; it was assumed that the microphytes existed in the soil, air, or water of humid regions, multiplying freely in these elements; that they were carried by air currents and in mists and vapors, infecting persons through the air breathed or the water which they drank; and in not a few places it was thought that malaria stood in some close relation to the bite of mosquitoes and other insects.
MOSQUITOES AND MALARIA.. JAMA. 1899;XXXIII(7):417-419. doi:10.1001/jama.1899.02450590047008