The microscopic organisms found in the blood of man and animals and their relation to disease. / By Timothy Richards Lewis.

  • Timothy Richards Lewis
Date:
1879
Catalogue details

Licence: Public Domain Mark

Credit: The microscopic organisms found in the blood of man and animals and their relation to disease. / By Timothy Richards Lewis. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    Professor Cohn favoured Dr. Kocli with a sketch of the same developmental process as seen under a higher power. This figure is also reproduced for purposes of comparison. Koch suggests that probably the ' spore' consists of a strongly refractive substance, probably oil, which is enveloped by a thin layer of proto- plasm—the latter being the substance capable of germination, and the former, perhaps, serving as nourishment during the germinating process. The foregoing, according to various writers, represents the complete cycle of development undergone by Bacillus anthracis. Davaine, it will be recollected, had found that animals eating diseased tis- sues mixed up with their food became themselves Virus, according: to Koch, inert ^ in aumentary canal. affcctcd, and he believcd that the spread of the disease could thus to some extent be easily accounted for. Koch, on the con- trary, finds that animals very susceptible to infection by inoculation, such as mice and rabbits, may devour such a mixture with impunity. Attempts to inoculate two dogs, a partridge, and a sparrow, proved fruitless. The latest contribution which has been made towards this enquiry is from the pen of Dr. J. Cossar Ewart.^ Dr. Ewart confirms Dr. J. cossarEwart's experiments. Koch's experiments in many points, and his description of the development of the rods into filaments [fig. 8, and fig. 9, (a)] corresponds with that of previous writers; but his description and figures of (b) o ® ® (» ^ ■(c) Fig. 9 . . . x ? diam. „ - „ J. Bacillus anthracis: (a) A filament containin? Fig. 8 . . . x ? diam. . ' ' , ■, , spores, becoming granular at one end, and snew- Bacillus anthracis : Rods undergoing segmentation ing transverse lines between the spores ; (b) Part and lengthening into a filament. (After Ewart.) of a filament containing a spore in process of , division ; (c) shews the different stages through which a spore passes in its development into a rod. (After Ewart.) the germination of the 'spores' are totally different. 'The spores,' writes Dr. Ewart, ' when free, according to previous observers, at once grow into rods, ' Quarterly Journal of Microscopical Science, Apiil 1878, p. 161.