Some personal observations made in Pennsylvania and in Texas regarding malarial fever and the anopheles mosquito / by Albert Woldert, M.D., of Tyler, Texas.

  • Woldert, Albert, 1867-1959
Date:
[1906?]
Catalogue details

Licence: In copyright

Credit: Some personal observations made in Pennsylvania and in Texas regarding malarial fever and the anopheles mosquito / by Albert Woldert, M.D., of Tyler, Texas. Source: Wellcome Collection.

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    from seven to ten days these same oocytes or zygotes de¬ velop in the interior many hundreds of small spindle- shaped spores or sporozoites of malarial fever and later these zygotes become so distended by the great number of spores that they rupture in much the same way as does the mother tick when it is filled with seed-ticks. These spores on becoming free in the abdominal cavity of the mosquito will then be washed upward into the salivary glands of the mosquito to be poured out with the saliva into the blood of man the moment the insect bites, and each of these spindle-shaped spores (in the mosquito) will in man become converted into the small intracor- puscular hyalin bodies and within 2 to 21 days give rise to chills. It should be remembered that the mosquito does not possess a heart nor a closed system of bloodvessels,1 but that the blood (which is white in color) flows freely throughout its entire system, being propelled along the back by what is known as the dorsal vein, a mere tube open at both ends and which contracts and expands with each pulsation, so that it is an easy matter for the spores of the malarial parasite, or spores of other disease-pro¬ ducing microorganisms, to be distributed throughout the entire body of the mosquito. Therefore, in an infected Anopheles the spores are not all washed into the salivary glands under the insect’s neck, but may be found in all parts of its body. One may readily understand how easy it would be for such an infinitesimal body as the spores of this malarial parasite to be distributed through¬ out the body of the mosquito when they will recall that fully developed parasites as Filaria sanguinis hominis have been found after dissection in different parts of the body of the mosquito, including the salivary glands. Just why one special kind of mosquito can act as the definitive host for the malarial parasites, while another genus does not seem to be able to do so, depends per¬ haps upon certain anatomic peculiarities and upon the nature of the tissue juices in certain types of mosqui-