Selected monographs.

  • New Sydenham Society
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    artificial malaria of animals* A priori, artificial production of malaria in the latter would seem unlikely, as in malarious dis- tricts most deadly to man they appear to enjoy a perfect immunity; and certain diseases and poisons which attack man seem not to affect animals, and vice versd. Experimental pathology has shown, however, that such im- munity is more relative than absolute; and the tubercular and diphtheritic infection have been produced in animals, while one of us (Klebs) has shown that syphilis may be communicated to monkeys. Contrasting the unhappy condition of man in, for example, the Pontine marshes, with the thriving state of thousands of mam- mals, there exposed much more completely to malarious infections, it is difficult to explain the immunity of the latter. The rule, however, seems to have its exceptions, as certain breeds of horses introduced into the Campagna are said to suffer from enlarged spleens; and flocks of goats are said to be deci- mated in such localities by disease attended with splenic enlarge- ment. Some part of the immunity of animals may be due to acclimatization, just as the negro race resists as no other can the malarious poison, and thrives in tropical lands uninhabitable by the less resistant white races. This may in part be the outcome of natural selection in the hereditary struggle against malaria aggression, and in the long course of centuries animals may acquire a power of resistance to malaria so long as it only reaches them through accustomed channels. The greater extent and tortuosity of the nasal respiratory passages, and the necessity for air laden with malaria germs to traverse such an extent of moist membrane, may, in animals, place them at an advantage in com- parison with man, whose respiration, unlike theirs, is chiefly buccal. Experiments might settle this question, but it only falls within our design to secure the introduction, into the circulation, of malaria poison, and to observe if a true malaria fever results. We confined ourselves to the subcutaneous injection of the sus- pected material, and obtained the positive results set forth in the next chapter. In order to judge of the precise nature of the fever so origi- * My experience coincides with that of Sir Joseph Fayrer and others, that a fever, clinically indistinguishable from typhoid, ar'ses in malarious countries, from a cause other than faecal emanatious.—E. D. 2
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