File:Handbook of medical entomology (1915) (14778497221).jpg

Identifier: handbookofmedic00rile (find matches)
Title: Handbook of medical entomology
Year: 1915 (1910s)
Authors: Riley, William Albert, 1876- Johannsen, Oskar Augustus, 1870-1961 Metcalf Collection (North Carolina State University). NCRS
Subjects: Insect pests Insects as carriers of disease Medical parasitology
Publisher: Ithaca, N.Y., The Comstock publishing company
Contributing Library: NCSU Libraries
Digitizing Sponsor: NCSU Libraries

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le, analternation of generations, of which the asexual stage is undergone inman, the sexual in certain species of mosquitoes. The mosquito istherefore the definitive host rather than the intermediate, as usuallystated. The complicated cycle may be made clearer by the diagram ofMiss Str>^ke (1912) which, by means of a double-headed mosquito(fig. 126) endeavors to show how infection takes place through thebiting of the human victim, (at A), in whom asexual miiltiplicationthen takes place, and how the sexual stages, taken up at B in thediagram, are passed in the body of the mosquito. The experimental proof that mosquitoes of the Anopheline groupare necessary agents in the transmission of malaria was afforded in1900 when two English physicians, Drs. Sambon and Low lived forthe three most malarial months in the midst of the Roman Campagna, Mosquitoes and Malaria 193 a region famous for centuries as a hot-bed of malaria. The twoexperimenters moved about freely throughout the day, exposed
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126. Life cycle of the malarial parasite. After Miss Anna Stryke. themselves to rains and all kinds of weather, drank marsh water,slept exposed to the marsh air, and, in short, did everything whichwas supposed to cause malaria, except that they protected them-selves thoroughly from mosquito bites, retiring at sunset to a mosquito- 194 Arthropods as Hosts of Pathogenic Protozoa proof hut. Though they took no quinine and all of their neighborssuffered from malaria, they were absolutely free from the disease.To complete the proof, mosquitoes which had fed in Rome onmalarious patients were sent to England and allowed to bite twovolunteers, one of them Dr. Mansons own son, who had not beenotherwise exposed to the disease. Both of these gentlemen con-tracted typical cases of malaria and the parasites were to be found inabundance in their blood. Since that timic there have been many practical demonstrationsof the fact that malaria is transmitted exclusively by the bite of mosquitoes and that

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