How to live in tropical Africa : a guide to tropical hygiene and sanitation the malaria problem the cause, prevention, and cure of malarial fever / by J. Murray, M.D. ; maps and climatological memoranda by E.G. Ravenstein ; edited by Leo Weinthal.

  • Murray, John.
Date:
[1912]
Catalogue details

Licence: In copyright

Credit: How to live in tropical Africa : a guide to tropical hygiene and sanitation the malaria problem the cause, prevention, and cure of malarial fever / by J. Murray, M.D. ; maps and climatological memoranda by E.G. Ravenstein ; edited by Leo Weinthal. Source: Wellcome Collection.

    96/350 (page 78)
    have been lying in the insect’s salivary glands. There are, according to Manson, Ross, and others, at least three kinds of malarial parasite, which are thus introduced into man, and which,, breeding true, cause their respective fevers ; and each kind of the malarial parasite, generally called by scientists the Plasmodium malar ice, has its special span of hours for running its complete life cycle in the human body, viz.: in the “ benign ” forms 24, 48, or 72, producing “ Quotidian, “ Tertian,” and “ Quartan” fever respectively. The “malig- nant” or JEstivo-Autumnal variety, has no definite span of maturation. But, as before stated, some authorities deny the existence of “ Quotidian ” fevers, holding them to be “double or overlapping Quartan. Still they are commonly seen clinically and must therefore be mentioned. The Life Cycle of the Benign Malarial Parasite. The development of the benign variety of the malarial parasite within the red blood-corpuscles of man, according to the most recent views of scientists, is shown in the accom- panying diagram Plate IV. To understand this diagram we must remember that the protozoa, to which the malarial parasite belongs, reproduce themselves both by simple cell division—the asexual method— and by the formation of male and female cells—the sexual method. Take the simplest illustration of this, namely, the reproduction of the Volvox globator, to which my son drew my attention. It is found commonly in ponds in England, and is a familiar microscopic object. This produces sexual and asexual spores—the sexual in autumn, the asexual in summer—either kind being capable of reproducing a perfect volvox when cast by the rupture of the mother cell into the water. (See Plate IV., c and d) It is noticeable that the sexual spores of the volvox are only produced in autumn, and the asexual in summer, a fact which, in the absence of the discovery of more definite scientific