Note 143 — Chapter VI · THE PHYSIOLOGICAL THEORY OF FERMENTATION. (continued 2)

In what way are we to account for so great a difference between the two fermentations that we have just described? Probably, it was owing to some modification effected in the medium by the previous life of the bacteria, or to the special character of the vibrios used in impregnation. Or, again, it might have been due to the action of the air, which, under the conditions of our second experiment, was not absolutely eliminated, since we took no precaution against its introduction at the moment of filling our flask, and this would tend to facilitate the multiplication of anaërobian vibrios, just as, under similar conditions, would have been the case if we had been dealing with a fermentation by ordinary yeast.