This explanation implies that the rate of fermentation after the action of the toluene represents the amount of fermenting complex present, a supposition which has been shown (p. 53) to be highly improbable. It further necessitates, as also pointed out independently by Euler and Ugglas [1911], a rapid destruction of the fermenting complex both in the process of fermentation and by the action of the antiseptic, as otherwise the store of zymase remaining in the dead cell would be practically the same as that contained in the living cell at the moment when it was subjected to the antiseptic, and this store would therefore suffice to carry out fermentation at the same rate in the dead as in the living cell. No such rapid destruction, however, occurs in yeast-juice, as judged by the rate of fermentation, which falls off [p126] slowly and to about the same extent in the presence or absence of toluene. Moreover, as shown above, it is highly probable that the actual amount of fermenting complex in yeast-juice is a large fraction of that present at any moment in the cell, and is capable under suitable conditions of producing fermentation at a rate comparable with that of the living cell. This last criticism also applies to the view expressed by Euler [Euler and Ugglas, 1911; Euler and Kullberg, 1911, 1, 2] that in the living cell the zymase is partly free and partly combined with the protoplasm; when the vital activity of the cell is interfered with, the combined portion of the zymase is thrown out of action and only that which was free remains active. The suggestion made by Rubner [1913] that the action of yeast on sugar is in reality chiefly a vital act, but that a small proportion of the change is due to enzyme action, is similar in its consequences to that of Euler and may be met by the same arguments. Buchner and Skraup [1914] have moreover shown that the effects of sodium chloride and toluene on the fermenting power of yeast which were observed by Rubner, can be explained in other ways.