Manual of veterinary microbiology / by Professors Mosselman and Liénaux ; translated and edited by R.R. Dinwiddie.

  • Mosselman, Gustave.
Date:
1894
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Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Manual of veterinary microbiology / by Professors Mosselman and Liénaux ; translated and edited by R.R. Dinwiddie. Source: Wellcome Collection.

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    fore arriving at the ceriter is itself shorter. How- ever, under natural conditions the duration of this latent period is influenced by various factors, such as the quantity of the virus, the richness in nerves, and the extent of the injury to these nerves. The action of the virus of rabies on the nerve cen- ters and on the nerves is indirect; this virus does not act as a chemical agent would, strychnine, for exam- ple. The anatomical changes, little visible to the naked eye, appear under the microscope as inflammatory lesions at different stages of their evolution. These lesions have their seat principally in the nerves of the bitten part and in the corresponding part of the spinal cord. They consist of congestions and capillary hemorrhages, with infiltration of leucocytes; other lesions observed are limited foci of necrosis, diverse degenerations of the central nerve cells, transforma- tion of the myeline, hypertrophy of the axis cylin- ders, etc. The rabid symptoms are the expression of the neu- ritis and myelitis which successively develop. These changes manifest themselves by phenomena of excite- ment or of depression according as they are more or less advanced. Such phenomena are usually suc- cessive in occurrence, but may appear separately; hence the two forms, furious rabies and dumb or paralytic rabies. Most frequently they are combined, and mixed forms result, intermediate between the two preceding, thus establishing the unity of the disease. The symptomatic tableau will naturally vary accord- ing to the part of the cerebro-spinal axis first invaded, and therefore according to the place of inoculation. The experiments of Pasteur, in which rabies was