Note 107 — Chapter V · The Alcoholic Ferments. (continued 2)

Although we believe that the aërobian ferment of a particular yeast may be produced by a kind of transformation of the cells of the latter, yet we admit that this question is open to some doubt. The facts which we unexpectedly discovered in connection with the caseous ferment should make us extremely careful, and disposed to inquire whether aërobian ferments do not originally, in a state of intermixture, form part of the ferments from which they spring. One reason which might incline us to believe this, is the fact that a ferment sometimes perishes without the appearance of aërobian ferment on the surface. There is nothing very natural indeed in the hypothesis that we advance, which sets aside the supposed intermixture; but, on the other hand, if the aërobian ferment is a particular ferment, simply intermixed with some other variety and developed by change of conditions, how are we to account for its great resemblance in appearance and mode of budding to the ferment on the surface of which it appears? This resemblance, however, might be accounted for very naturally if the two ferments were originally related.