A manual of bacteriology / by A.B. Griffiths.

  • Griffiths, A. B. (Arthur Bower), 1859-
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: A manual of bacteriology / by A.B. Griffiths. Source: Wellcome Collection.

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    essential attributes that indicate the infectious nature of tlie pathogenic microbe, viz., its vaccinal property. Besides, Chauveau has further shown that the non-virulent Bacillus anthracis may be revivified by degrees when grown in suitable media. These researches do not point to any transformation of Bacillus anthracis into a non-pathogenic species, but simply show that oxygen under pressure is capable of modifying the microbe's pathogenic power. In fact, microbes have the power of adapt- ing themselves to considerable variation of external conditions; but this does not involve permanent change in the organism. Microbes belong to the vegetal kingdom; in other words, they are fungi. As they multiply by re- peated subdivision, and also frequently reproduce themselves by spores, which are formed endogen- ously, they are grouped together in a class called the Schizoviycetes, splitting fungi, or Spaltpilze, as the German naturalists term them. The forms of microbian cells vary considerably— they are round, ovate, elliptical, cylindrical, etc. Microbes live isolated, singly, or in larger or smaller colonies, ox, in many cases, united in pairs, or many together in threads or groups. Nearly all microbes possess two different modes of life: one of motion and another of rest. In certain conditions they are extremely motile, and wlien they swarm in a drop of water or other fluid they move among each other in all directions; sometimes rotating round their longitudinal axis, while in other cases the move- ment is an oscilhiting one, or the threads alternately